In plants , 14 - 3 - 3 proteins are important modulators of protein-protein interactions in response to environmental stresses .

The aim of the present work was to characterize one Opuntia ficus-indica 14 - 3 - 3 and get information about its client proteins .

To achieve this goal , O. ficus-indica 14 - 3 - 3 cDNA , named as Op14 - 3 - 3 μ , was amplified by 3'-RACE methodology .

Op14 - 3 - 3 μ contains an Open Reading Frame of 786 bp encoding a 261 amino acids protein .

Op14 - 3 - 3 μ cDNA was cloned into a bacterial expression system and recombinant protein was purified .

Differential Scanning Fluorimetry , Dynamic Light Scattering , and Ion Mobility-Mass Spectrometry were used for Op14 - 3 - 3 μ protein characterization , and Affinity-Purification-Mass Spectrometry analysis approach was used to obtain information about their potential client proteins .

Pyrophosphate-fructose 6-phosphate 1-phosphotransferase , ribulose bisphosphate carboxylase large subunit , and vacuolar-type H(+)-ATPase were identified .

Interestingly chorismate mutase p-prephenate dehydratase was also identified .

Op14 - 3 - 3 μ down-regulation was observed in Opuntia calluses when they were induced with Jasmonic Acid , while increased accumulation of Op14 - 3 - 3 μ protein was observed .

The putative interaction of 14 - 3 - 3 μ with chorismate mutase , which have not been reported before , suggest that Op14 - 3 - 3 μ could be an important regulator of metabolites biosynthesis and responses to stress in Opuntia spp .

SIGNIFICANCE : Opuntia species are important crops in arid and semiarid areas worldwide , but despite its relevance , little information about their tolerance mechanism to cope with harsh environmental conditions is reported .

14 - 3 - 3 proteins have gained attention due to its participation as protein-protein regulators and have been linked with primary metabolism and hormones responses .

Here we present the characterization of the first Opuntia ficus-indica 14 - 3 - 3 ( Op14 - 3 - 3 ) protein using affinity purification-mass spectrometry ( AP-MS ) strategy .

A novel Op14 - 3 - 3 client protein has been identified ; the chorismate mutase p-prephenate dehydratase , key enzyme that links the primary with secondary metabolism .

The present results open new questions about the Opuntia spp .

pathways mechanisms in response to environmental stress and the importance of 14 - 3 - 3 proteins in betalains biosynthesis .


Plants respond to proximate neighbors with a suite of responses that comprise the shade avoidance syndrome .

These phytochrome-mediated responses include hyponasty ( i.e. a more vertical orientation of leaves ) and enhanced stem and petiole elongation .

We showed recently that ethylene-insensitive tobacco ( Nicotiana tabacum ) plants ( Tetr ) have reduced responses to neighbors , showing an important role for this gaseous plant hormone in shade avoidance .

Here , we investigate interactions between phytochrome signaling and ethylene action in shade avoidance responses .

Furthermore , we investigate if ethylene acts in these responses through an interaction with the GA class of hormones .

Low red to far-red light ratios ( R : FR ) enhanced ethylene production in wild-type tobacco , resulting in shade avoidance responses , whereas ethylene-insensitive plants showed reduced shade avoidance responses .

Plants with inhibited GA production showed hardly any shade avoidance responses at all to either a low R : FR or increased ethylene concentrations .

Furthermore , low R : FR enhanced the responsiveness of hyponasty and stem elongation in both wild-type and Tetr plants to applied GA(3 ) , with the stem elongation process being more responsive to GA(3 ) in the wild type than in Tetr .

We conclude that phytochrome-mediated shade avoidance responses involve ethylene action , at least partly by modulating GA action .


Beneficial soil microorganisms can affect plant growth and resistance by the production of volatile organic compounds ( VOCs ) .

Yet , little is known on how VOCs from soil-borne plant pathogens affect plant growth and resistance .

Here we show that VOCs released from mycelium and sclerotia of the fungal root pathogen Rhizoctonia solani enhance growth and accelerate development of Arabidopsis thaliana .

Seedlings briefly exposed to the fungal VOCs showed similar phenotypes , suggesting that enhanced biomass and accelerated development are primed already at early developmental stages .

Fungal VOCs did not affect plant resistance to infection by the VOC-producing pathogen itself but reduced aboveground resistance to the herbivore Mamestra brassicae .

Transcriptomics of A. thaliana revealed that genes involved in auxin signaling were up-regulated , whereas ethylene and jasmonic acid signaling pathways were down-regulated by fungal VOCs .

Mutants disrupted in these pathways showed similar VOC-mediated growth responses as the wild-type A. thaliana , suggesting that other yet unknown pathways play a more prominent role .

We postulate that R. solani uses VOCs to predispose plants for infection from a distance by altering root architecture and enhancing root biomass .

Alternatively , plants may use enhanced root growth upon fungal VOC perception to sacrifice part of the root biomass and accelerate development and reproduction to survive infection .


BACKGROUND : Studies in Arabidopsis show that DELLA genes may differentially affect responses to biotrophic and necrophic pathogens .

A recent report based on the study of DELLA-producing reduced height ( Rht ) genes in wheat and barley also hypothesized that DELLA genes likely increased susceptibility to necrotrophs but increased resistance to biotrophs .

RESULTS : Effects of uzu , a non-GA ( gibberellic acid)-responsive semi-dwarfing gene , on Fusarium crown rot ( FCR ) resistance in barley were investigated .

Fifteen pairs of near isogenic lines for this gene were generated and assessed under two different temperature regimes .

Similar to its impacts on plant height , the semi-dwarfing gene uzu also showed larger effects on FCR severity in the high temperature regime when compared with that in the low temperature regime .

CONCLUSIONS : Results from this study add to the growing evidence showing that the effects of plant height on Fusarium resistances are unlikely related to DELLA genes but due to direct or indirect effects of height difference per se .

The interaction between these two characteristics highlights the importance of understanding relationships between resistance and other traits of agronomic importance as the value of a resistance gene could be compromised if it dramatically affects plant development and morphology .


Two slightly differing cDNA clones corresponding to the wound-inducible form of a previously characterized seed myrosinase-associated protein ( MyAP ) have been isolated from Brassica napus L. The transcripts corresponding to the induced MyAP ( iMyAP ) were found to be developmentally regulated in various vegetative organs .

Both young and old leaves exhibited wound-inducible iMyAP expression .

Furthermore , in the young plant , wounding resulted in a systemic increase in leaves located both acropetally and basipetally to the wounded leaf .

Also , the iMyAP transcripts were induced by methyl jasmonate , jasmonic acid and abscisic acid .

The different inductions could be antagonized by salicylic acid .

A general responsiveness in methyl-jasmonate-treated leaves was demonstrated by in situ hybridization .

No effect on the amount of iMyAP transcript was detected after feeding the plants with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid .

The similarity between MyAP and a lipase from Arabidopsis thaliana indicated a possible function in liberating acylated glucosinolates from their acyl group , thereby making them available for hydrolysis by the myrosinase enzymes .

We also report on a reduction in the amount of myrosinase transcripts derived from the vegetatively expressed MB-gene family after treatment with exogenously applied salicylic acid or abscisic acid .


Multiple isoforms of chitinases participate in plant defense against outside invaders .

However , the functions of hydrolase family 19 ( GH19 ) chitinases on pest control remain largely unknown .

Here we reported the isolation and functional analysis of a gene CsChi19 , which encodes a GH19 endochitinase protein of 332 amino acid residues from tea plant ( Camellia sinensis ) .

CsChi19 expression levels were upregulated in response to mechanical wounding , infestation by two important pests : the tea geometrid Ectropis grisescens and the tea green leafhopper Empoasca ( Matsumurasca ) onukii , a fungal pathogen Colletotrichum fructicola , and treatment with two phytohormones : jasmonic acid ( JA ) and salicylic acid .

CsChi19 was heterologously expressed in Escherichia coli , and its catalytic function was further elucidated .

The protein could hydrolyze colloidal chitin , and the optimum temperature and pH for its activity was 40 ° C and pH 5.0 .

CsChi19 were found to be toxic to tea pests when they were fed on artificial diets containing this protein .

Interestingly , the regurgitant derived from E. grisescens fed with artificial diets containing CsChi19 protein induced stronger expression of CsMPK3 , more JA burst , more accumulation of defense-related secondary metabolites , and more emission of volatiles than the regurgitant derived from E. grisescens fed only with artificial diets .

Our results provide first evidence that CsChi19 is involved in mediating a novel defense mechanism of tea plant through altering the composition of the regurgitant .


Suspension cultures were incubated in the presence and absence of gibberellic acid ( GA(3 ) ) in an attempt to define a new experimental system for study of the molecular action of gibberellins upon growth .

Unlike many suspension cultures , an auxin-independent green clone from spinach ( Spinacia oleracea L. ) and an auxin-dependent line of " Paul 's Scarlet " rose ( Rosa sp. ) were promoted in expansion growth by GA(3 ) at 10(-11 ) to 10(-6 ) molar .

In Rosa the cells also elongated upon GA(3 ) treatment whereas in Spinacia they remained isodiametric .

Attempts were made to intensify the response .

The effect of GA(3 ) in Spinacia was stronger when gas exchange between the culture and the laboratory air was facilitated .

The response of Rosa was dependent on the presence of a cytokinin , although this culture did not require exogenous cytokinin for serial subculture .

GA(3 ) antagonized the growth retardant AMO-1618 in Rosa but not in Spinacia .

In general , conditions that enhanced growth also rendered GA(3 ) a more effective promoter ; conversely , GA(3 ) tended to become inhibitory under conditions that permitted only slow growth .


Abscisic acid ( ABA ) , auxins , cytokinins , gibberellic acid , alone or in combination were tested for their effects on short-term sucrose uptake in sugar beet ( Beta vulgaris cv USH-20 ) roots .

The effect of ABA on active sucrose uptake varied from no effect to the more generally observed 1.4-to 3.0-fold stimulation .

A racemic mixture of ABA and its trans isomer were more stimulatory than ABA alone .

Pretreating and/or simultaneously treating the tissue with K(+ ) or IAA prevented the ABA response while cytokinins and gibberellic acid did not .

While the variable sensitivities of beet root to ABA may somehow be related to the auxin and alkali cation status of the tissue , tissue sensitivity to ABA was not correlated with ABA uptake , accumulation , or metabolic patterns .

In contrast to ABA , indoleacetic acid ( IAA ) and other auxins strongly inhibited active sucrose uptake in beet roots .

Cytokinins enhanced the auxin-induced inhibition of sucrose uptake but ABA and gibberellic acid did not modify or counteract the auxin effect .

Trans-zeatin , benzyladenine , kinetin , and gibberellins had no effect on active sucrose uptake .

None of the hormones or hormone mixtures tested had any significant effect on passive sucrose uptake .

The effects of IAA and ABA on sucrose uptake were detectable within 1 h suggesting a rather close relationship between the physiological activities of IAA and ABA and the operation of the active transport system .


Artemisinin is a type of sesquiterpene lactone well known as an antimalarial drug , and is specifically produced in glandular trichomes of Artemisia annua .

However , the regulatory network for the artemisinin biosynthetic pathway remains poorly understood .

Exploration of trichome-specific transcription factors would facilitate the elucidation of regulatory mechanism of artemisinin biosynthesis .

The WRKY transcription factor GLANDULAR TRICHOME-SPECIFIC WRKY 1 ( AaGSW1 ) was cloned and analysed in A. annua .

AaGSW1 exhibited similar expression patterns to the trichome-specific genes of the artemisinin biosynthetic pathway and AP2/ERF transcription factor AaORA .

A β-glucuronidase ( GUS ) staining assay further demonstrated that AaGSW1 is a glandular trichome-specific transcription factor .

AaGSW1 positively regulates CYP71AV1 and AaORA expression by directly binding to the W-box motifs in their promoters .

Overexpression of AaGSW1 in A. annua significantly improves artemisinin and dihydroartemisinic acid contents ; moreover , AaGSW1 can be directly regulated by AaMYC2 and AabZIP1 , which are positive regulators of jasmonate (JA)- and abscisic acid (ABA)-mediated artemisinin biosynthetic pathways , respectively .

These results demonstrate that AaGSW1 is a glandular trichome-specific WRKY transcription factor and a positive regulator in the artemisinin biosynthetic pathway .

Moreover , we propose that two trifurcate feed-forward pathways involving AaGSW1 , CYP71AV1 and AaMYC2/AabZIP1 function in the JA/ABA response in A. annua .


Gibberellin ( GA ) regulates various plant growth and developmental processes , but its role in pathogen attack , and especially nematode-plant interactions , still remains to be elucidated .

An in-depth characterization of the role of GA in nematode infection was conducted using mutant lines of rice , chemical inhibitors , and phytohormone measurements .

Our results showed that GA influences rice-Meloidogyne graminicola interactions in a concentration-dependent manner .

Foliar spray of plants with a low concentration of gibberellic acid enhanced nematode infection .

Biosynthetic and signaling mutants confirmed the importance of gibberellin for rice susceptibility to M. graminicola infection .

Our study also demonstrates that GA signaling suppresses jasmonate (JA)-mediated defense against M. graminicola , and likewise the JA-induced defense against M. graminicola requires SLENDER RICE1 (SLR1)-mediated repression of the GA pathway .

In contrast to observations from other plant-pathogen interactions , GA plays a dominant role over JA in determining susceptibility to M. graminicola in rice .

This GA-induced nematode susceptibility was largely independent of auxin biosynthesis , but relied on auxin transport .

In conclusion , we showed that GA-JA antagonistic crosstalk is at the forefront of the interaction between rice and M. graminicola , and SLR1 plays a central role in the JA-mediated defense response in rice against this nematode .


Many induced responses in plants are systemic .

Therefore , root-induced responses may alter leaf quality for shoot herbivores .

Previously , we found that root and shoot application of jasmonic acid ( JA ) to feral Brassica oleracea both induced glucosinolates in the leaves .

However , the types of glucosinolates that increased in root- and shoot induced plants were different .

Here we analyse whether primary metabolites , such as sugars and amino acids , are also differentially affected .

Moreover , we test whether chemical differences in root- and shoot-induced plants differentially affect growth of the generalist Mamestra brassicae and the specialist Pieris rapae .

Comprehensive analysis of glucosinolates , amino acid and sugars with principal component analysis revealed that leaf chemical profiles were affected both by JA application and by the organ that was induced .

Shoot-induction increased indole glucosinolates , whereas root-induction induced aliphatic glucosinolates in the leaves .

Leaves of shoot-induced plants had lower total sugar and total amino acid levels , whereas in root-induced plants only total sugar levels were significantly decreased .

(Iso)leucine responded significantly different from the general trend , which allowed us to discuss the potential role of Myb transcription factors which are coordinating JA-induced glucosinolate and amino acid responses in Arabidopsis thaliana .

Both M. brassicae and P. rapae grew the slowest on leaves of shoot-induced plants .

M. brassicae growth and survival was also reduced on root-induced plants , whereas P. rapae growth on these plants was similar to that on controls .

Specialist and generalist herbivores thus are differentially affected by the chemical changes after root and shoot-JA application .


The phloem plays a crucial role in assimilate and nutrient transport , pathogen response , and plant growth and development .

Yet , few species have yielded pure phloem exudate and , if proteins need to be analysed , those species may not have sequenced genomes , making identification difficult .

The enrichment of Arabidopsis thaliana phloem exudate in amounts large enough to allow for metabolite and protein analysis is described .

Using this method , it was possible to identify 65 proteins present in the Arabidopsis phloem exudate .

The majority of these proteins could be grouped by response to pathogens , stress , or hormones , carbon metabolism , protein interaction , modification , and turnover , and transcription factors .

Along with putative lipid-binding proteins , several lipids and fatty acids could be identified .

Only a few examples exist of lipids ( jasmonic acid , oxylipins ) or lipid-binding proteins ( DIR1 , acyl-CoA-binding protein ) in the phloem .

Finding hydrophobic compounds in an aqueous environment is not without precedence in biological systems : human blood contains a variety of lipids , many of which play a significant role in human health .

In blood , lipids are transported while bound to proteins .

The present findings of lipids and lipid-binding proteins in phloem exudates suggest that a similar long-distance lipid signalling exists in plants and may play an important role in plant growth and development .


Plant grafting is a sequential wound healing process .

However , whether wounding induces a different jasmonic acid ( JA ) response within half a day ( 12 h ) after grafting or non-grafting remains unclear .

Using the tomato hypocotyl grafting method , we show that grafting alleviates the asymmetrical accumulation of JA and jasmonic acid isoleucine conjugate ( JA-Ile ) in scion and rootstock caused by wounding , and from 2 h after tomato micrografting , grafting obviously restored the level of JA-Ile in the scion and rootstock .

Meanwhile , five JA-related genes , SlLOX11 , SlAOS , SlCOI1 , SlLAPA and SlJA2L , are detected and show significant changes in transcriptional expression patterns within 12 h of grafting , from asymmetrical to symmetrical , when the expression of 30 JA- and defense-related genes were analyzed .

The results indicated that grafting alleviates the asymmetrical JA and defense response between scion and rootstock of the tomato hypocotyl within 12 h as induced by wounding .

Moreover , we demonstrate that in the very early hours after grafting , JA-related genes may be involved in a molecular mechanism that changes asymmetrical expression as induced by wounding between scion and rootstock , thereby promoting wound healing and grafting success .


The genes of the gibberellin ( GA ) biosynthesis pathway in Gibberella fujikuroi are organized in a gene cluster consisting of at least seven genes .

Here we report the cloning and characterization of smt , a gene encoding a membrane transporter of the major facilitator super-family 1 , which is located next to the GA gene cluster .

Since pathway-specific transporters occur frequently in prokaryotic and fungal antibiotic and toxin clusters , smt was thought to be involved in GA secretion .

The gene is expressed in mycelium grown under GA-production conditions , but not when the GA biosynthesis is repressed by high amounts of ammonium .

To investigate the function of SMT , gene replacement experiments were performed .

The smt-mutants did not show any reduction in the GA yield ; and gibberellic acid or its precursors did not influence the gene expression .

However , sugar alcohols , such as myo-inositol , sorbitol and mannitol , induced the expression of smt .

The results demonstrate that the smt gene does not play an essential role in biosynthesis and secretion of GAs in G. fujikuroi , despite the location adjacent to the GA gene cluster .


Certain plant growth promoting bacteria have ability to ameliorate abiotic and/or biotic stressors , which can be exploited to enhance plant growth and productivity of the plants under stress conditions .

Therefore , the present study aimed to examine the role of a rhizospheric bacterial isolate SBP-9 isolated from Sorghum bicolor ( i ) in promoting the wheat plant growth under salinity stress , and ( ii ) in enhancing the defense response in wheat against fungal pathogen " Fusarium graminearum . " The test isolate possessed plant growth promoting ( PGP ) traits including ACC deaminase ( ACCD ) , gibberellic acid , indole acetic acid ( IAA ) , siderophore , and inorganic phosphate solubilization .

Under salt ( NaCl ) stress , inoculation of this isolate to wheat plant significantly increased plant growth in terms of various growth parameters such as shoot length/root length ( 20 - 39 % ) , fresh weight/dry weight ( 28 - 42 % ) , and chlorophyll content ( 24 - 56 % ) following inoculation of test isolate SBP-9 .

Bacterial inoculation decreased the level of proline , and malondialdehyde , whereas elevated the antioxidative enzymatic activities of superoxide-dismutase ( SOD ; 28 - 41 % ) , catalase ( CAT ; 24 - 56 % ) , and peroxidase ( POX ; 26 - 44 % ) .

Furthermore , it also significantly decreased the Na(+ ) accumulation in both shoot and roots in the range of 25 - 32 % , and increased the K(+ ) uptake by 20 - 28 % , thereby favoring the K(+)/Na(+ ) ratio .

On the other hand , the test isolate also enhanced the level of defense enzymes like β-1 , 3 glucanase , phenylalanine ammonia lyase ( PAL ) , peroxidae ( PO ) , and polyphenol oxidase ( PPO ) , which can protect plants from the infection of pathogens .

The result of colonization test showed an ability of the test isolate to successfully colonize the wheat plants .

These results indicate that Stenotrophomonas maltophilia SBP-9 has potential to promote the wheat growth under biotic and abiotic ( salt ) stressors directly or indirectly and can be further tested at field level for exploitation as bioinoculant .


A rapid , selective , sensitive , accurate , and inexpensive immunosensor for gibberellin acid detection was designed by coupling immunoassay with the square wave anodic stripping voltammetry ( SWASV ) technique involving copper ion labeled antigen in the competitive immunoreaction .

The response signal expressed as the percentage of current reduction CR % ( y ) is linearly related to the concentration of GA ( x ) in the 1 microg/mL to approximately 150 microg/mL range with a regression equation of the form y = 0.44x + 15.59 and a correlation coefficient of 0.99 .

The results of the immunosensor assay were compared with those obtained by HPLC and ELISA , which show a satisfactory agreement .

The immunosensor was used to determine the GA content in the hybrid rice grain samples taken in the growing period .


Jasmonic acid is a carbocyclic fatty acid that is biosynthesized from alpha-linolenic acid in several steps .

The formation of the ring structure of jasmonic acid is catalyzed by the enzyme allene oxide cyclase ( EC 5.3.99.6 ) and involves the cyclization of an unstable allene oxide into the cyclopentenone 12-oxo-10,15(Z)-phytodienoic acid .

In this study , a number of allene oxides were generated , and their enzymatic and nonenzymatic cyclization into cyclopentenones was investigated .

Nonenzymatic cyclization was observed with allene oxides having one pair of conjugated double bonds and an additional isolated double bond in the beta , gamma position relative to the epoxide group , i.e. , the partial structure 4,5-epoxy-1,3,7-octatriene .

Enzymatic cyclization took place provided that this structural element was inserted in the fatty acid chain with its epoxide group in the n-6,7 position and the isolated double bond in the n-3 position .

A number of oxygenated fatty acids having structural features in common with the natural allene oxides were tested as inhibitors of allene oxide cyclase .

Fatty acids having an allene oxide structure in the n-6,7 position but lacking the double bond in the n-3 position , as well as fatty acids having a saturated epoxide group in the n-6,7 position , served as competitive inhibitors of the enzyme .

Data on the substrate specificity of allene oxide synthase ( EC 4.2.1.92 ) from corn seeds indicated that fatty acid hydroperoxides with a double bond at n-3 and with the hydroperoxide function at n-6 exhibit the highest affinity but the slowest reaction velocity .


Calmodulin ( CaM ) plays an important role in sensing and transducing changes in cellular Ca2 + concentration in response to several biotic and abiotic stresses .

Although CaM is implicated in plant-pathogen interactions , its molecular targets and their role in defense signaling pathway(s ) are poorly understood .

To elucidate the signaling pathways that link CaM to defense responses , we screened a cDNA library constructed from bean leaves undergoing a hypersensitive response ( HR ) with radiolabeled CaM isoforms .

A total of 26 putative CBPs were identified .

Sequencing of the cDNAs revealed that they represent 8 different genes .

They are homologues of previously identified CaM-binding proteins ( CBPs ) in other systems .

However , some CBPs are novel members of known CBP families .

The proteins encoded by these clones bound CaM in a Ca2 + -dependent manner .

To determine if these CBPs are involved in plant defense responses , we analyzed their expression in bean leaves inoculated with compatible , incompatible and nonpathogenic bacterial strains .

Expression of three CBPs including an isoform of cyclic nucleotide-gated channels ( PvCNGC-A ) and two hypothetical proteins ( PvCBP60-C and PvCBP60-D ) was induced whereas the expression of two other isoforms of CNGCs ( PvCNGC-B and PvCNGC-C ) was repressed in response to incompatible pathogens .

The expression of the rest , a small auxin up RNA ( PvSAUR1 ) and two hypothetical proteins ( PvCBP60-A and PvCBP60-B ) , was not changed .

The expression of most of the pathogen-regulated genes was also affected by salicylic acid , jasmonic acid , hydrogen peroxide and a fungal elicitor , which are known to induce defense responses .

Our results strongly suggest that at least five bean CBPs are involved in plant defense responses .


Biotic and abiotic stress induces the formation of galactolipids esterified with the phytohormones 12-oxo-phytodienoic acid ( OPDA ) and dinor-oxo-phytodienoic acid ( dnOPDA ) in Arabidopsis thaliana .

The biosynthetic pathways of free (dn)OPDA is well described , but it is unclear how they are incorporated into galactolipids .

We herein show that (dn)OPDA containing lipids are formed rapidly after disruption of cellular integrity in leaf tissue .

Five minutes after freeze-thawing , 60 - 70 % of the trienoic acids esterified to chloroplast galactolipids are converted to (dn)OPDA .

Stable isotope labeling with (18)O-water provides strong evidence for that the fatty acids remain attached to galactolipids during the enzymatic conversion to (dn)OPDA .


Selected strains of nonpathogenic rhizobacteria can reduce disease in foliar tissues through the induction of a defense state known as induced systemic resistance ( ISR ) .

Compared with the large body of information on ISR in dicotyledonous plants , little is known about the mechanisms underlying rhizobacteria-induced resistance in cereal crops .

Here , we demonstrate the ability of Pseudomonas fluorescens WCS374r to trigger ISR in rice ( Oryza sativa ) against the leaf blast pathogen Magnaporthe oryzae .

Using salicylic acid (SA)-nonaccumulating NahG rice , an ethylene-insensitive OsEIN2 antisense line , and the jasmonate-deficient mutant hebiba , we show that this WCS374r-induced resistance is regulated by an SA-independent but jasmonic acid/ethylene-modulated signal transduction pathway .

Bacterial mutant analysis uncovered a pseudobactin-type siderophore as the crucial determinant responsible for ISR elicitation .

Root application of WCS374r-derived pseudobactin ( Psb374 ) primed naive leaves for accelerated expression of a pronounced multifaceted defense response , consisting of rapid recruitment of phenolic compounds at sites of pathogen entry , concerted expression of a diverse set of structural defenses , and a timely hyperinduction of hydrogen peroxide formation putatively driving cell wall fortification .

Exogenous SA application alleviated this Psb374-modulated defense priming , while Psb374 pretreatment antagonized infection-induced transcription of SA-responsive PR genes , suggesting that the Psb374- and SA-modulated signaling pathways are mutually antagonistic .

Interestingly , in sharp contrast to WCS374r-mediated ISR , chemical induction of blast resistance by the SA analog benzothiadiazole was independent of jasmonic acid/ethylene signaling and involved the potentiation of SA-responsive gene expression .

Together , these results offer novel insights into the signaling circuitry governing induced resistance against M. oryzae and suggest that rice is endowed with multiple blast-effective resistance pathways .


When plants are attacked by pathogens , they defend themselves with an arsenal of defence mechanisms , both passive and active .

The active defence responses , which require de novo protein synthesis , are regulated through a complex and interconnected network of signalling pathways that mainly involve three molecules , salicylic acid ( SA ) , jasmonic acid ( JA ) , and ethylene ( ET ) , and which results in the synthesis of pathogenesis-related ( PR ) proteins .

Microbe or elicitor-induced signal transduction pathways lead to ( i ) the reinforcement of cell walls and lignification , ( ii ) the production of antimicrobial metabolites ( phytoalexins ) , and ( iii ) the production of reactive oxygen species ( ROS ) and reactive nitrogen species ( RNS ) .

Among the proteins induced during the host plant defence , class III plant peroxidases ( EC 1.11.1.7 ; hydrogen donor : H(2)O(2 ) oxidoreductase , Prxs ) are well known .

They belong to a large multigene family , and participate in a broad range of physiological processes , such as lignin and suberin formation , cross-linking of cell wall components , and synthesis of phytoalexins , or participate in the metabolism of ROS and RNS , both switching on the hypersensitive response ( HR ) , a form of programmed host cell death at the infection site associated with limited pathogen development .

The present review focuses on these plant defence reactions in which Prxs are directly or indirectly involved , and ends with the signalling pathways , which regulate Prx gene expression during plant defence .

How they are integrated within the complex network of defence responses of any host plant cell will be the cornerstone of future research .


Staphylococcus aureus is a ubiquitous gram-positive bacterium that can cause superficial to serious systemic infections in animals and humans .

Here we report the development of a plant infection model to study the pathogenesis of this bacterium .

Three global regulatory mutants , RN6911 ( agr- ) , ALC 488 ( sarA- ) ALC 842 ( sarA-/agr- ) and an alpha-toxin mutant defective in biofilm formation ( DU1090 ) which are attenuated in animal pathogenesis , were also attenuated in their ability to infect plants , suggesting that these regulators that mediate synthesis of virulence factors essential for animal pathogenesis are also required for plant pathogenesis .

Further , using Arabidopsis plants altered in defense responses such as the transgenic lines NahG [ defective in salicylic acid ( SA ) accumulation ] , and 35S-LOX2- ( defective in jasmonic acid production and hyper-accumulator of SA ) , and mutants ics1 ( depleted in SA accumulation ) , and npr1 - 1 ( non-expressor of pathogenesis-related protein ) we show that resistance of Arabidopsis to typical plant pathogens and the animal pathogen S. aureus is conserved and is mediated by SA .

The data presented here suggest that Arabidopsis thaliana resistance to S. aureus is mediated either by a direct effect of SA on the pathogen , specifically one that affects the attachment/aggregate formation on the root surface and reduces the pathogen 's virulence , or by SA-dependent , NPR1-independent host responses .


Plants coordinate and tightly regulate pathogen defense by the mostly antagonistic salicylate (SA)- and jasmonate (JA)-mediated signaling pathways .

Here , we show that the previously uncharacterized glucosyltransferase UGT76B1 is a novel player in this SA-JA signaling crosstalk .

UGT76B1 was selected as the top stress-induced isoform among all 122 members of the Arabidopsis thaliana UGT family .

Loss of UGT76B1 function leads to enhanced resistance to the biotrophic pathogen Pseudomonas syringae and accelerated senescence but increased susceptibility toward necrotrophic Alternaria brassicicola .

This is accompanied by constitutively elevated SA levels and SA-related marker gene expression , whereas JA-dependent markers are repressed .

Conversely , UGT76B1 overexpression has the opposite effect .

Thus , UGT76B1 attenuates SA-dependent plant defense in the absence of infection , promotes the JA response , and delays senescence .

The ugt76b1 phenotypes were SA dependent , whereas UGT76B1 overexpression indicated that this gene possibly also has a direct effect on the JA pathway .

Nontargeted metabolomic analysis of UGT76B1 knockout and overexpression lines using ultra-high-resolution mass spectrometry and activity assays with the recombinant enzyme led to the ab initio identification of isoleucic acid ( 2-hydroxy-3-methyl-pentanoic acid ) as a substrate of UGT76B1 .

Exogenously applied isoleucic acid increased resistance against P. syringae infection .

These findings indicate a novel link between amino acid-related molecules and plant defense that is mediated by small-molecule glucosylation .


Brassinosteroids ( BRs ) are a group of naturally occurring plant steroidal compounds with wide-ranging biological activity that offer the unique possibility of increasing crop yields through both changing plant metabolism and protecting plants from environmental stresses .

In recent years , genetic and biochemical studies have established an essential role for BRs in plant development , and on this basis BRs have been given the stature of a phytohormone .

A remarkable feature of BRs is their potential to increase resistance in plants to a wide spectrum of stresses , such as low and high temperatures , drought , high salt , and pathogen attack .

Despite this , only a few studies aimed at understanding the mechanism by which BRs promote stress resistance have been undertaken .

Studies of the BR signaling pathway and BR gene-regulating properties indicate that there is cross-talk between BRs and other hormones , including those with established roles in plant defense responses such as abscisic acid , jasmonic acid , and ethylene .

Recent studies aimed at understanding how BRs modulate stress responses suggest that complex molecular changes underlie BR-induced stress tolerance in plants .

Analyses of these changes should generate exciting results in the future and clarify whether the ability of BRs to increase plant resistance to a range of stresses lies in the complex interactions of BRs with other hormones .

Future studies should also elucidate if BRI1 , an essential component of the BR receptor , directly participates in stress response signaling through interactions with ligands and proteins involved in plant defense responses .


Two key genes in terpenoid indole alkaloid biosynthesis , Tdc and Str , encoding tryptophan decarboxylase and strictosidine synthase , respectively , are coordinately induced by fungal elicitors in suspension-cultured Catharanthus roseus cells .

We have studied the roles of the jasmonate biosynthetic pathway and of protein phosphorylation in signal transduction initiated by a partially purified elicitor from yeast extract .

In addition to activating Tdc and Str gene expression , the elicitor also induced the biosynthesis of jasmonic acid .

The jasmonate precursor alpha-linolenic acid or methyl jasmonate ( MeJA ) itself induced Tdc and Str gene expression when added exogenously .

Diethyldithiocarbamic acid , an inhibitor of jasmonate biosynthesis , blocked both the elicitor-induced formation of jasmonic acid and the activation of terpenoid indole alkaloid biosynthetic genes .

The protein kinase inhibitor K-252a abolished both elicitor-induced jasmonate biosynthesis and MeJA-induced Tdc and Str gene expression .

Analysis of the expression of Str promoter/gusA fusions in transgenic C. roseus cells showed that the elicitor and MeJA act at the transcriptional level .

These results demonstrate that the jasmonate biosynthetic pathway is an integral part of the elicitor-triggered signal transduction pathway that results in the coordinate expression of the Tdc and Str genes and that protein kinases act both upstream and downstream of jasmonates .


BACKGROUND : The plant-specific TCP transcription factor family , which is involved in the regulation of cell growth and proliferation , performs diverse functions in multiple aspects of plant growth and development .

However , no comprehensive analysis of the TCP family in watermelon ( Citrullus lanatus ) has been undertaken previously .

RESULTS : A total of 27 watermelon TCP encoding genes distributed on nine chromosomes were identified .

Phylogenetic analysis clustered the genes into 11 distinct subgroups .

Furthermore , phylogenetic and structural analyses distinguished two homology classes within the ClTCP family , designated Class I and Class II .

The Class II genes were differentiated into two subclasses , the CIN subclass and the CYC/TB1 subclass .

The expression patterns of all members were determined by semi-quantitative PCR .

The functions of two ClTCP genes , ClTCP14a and ClTCP15 , in regulating plant height were confirmed by ectopic expression in Arabidopsis wild-type and ortholog mutants .

CONCLUSIONS : This study represents the first genome-wide analysis of the watermelon TCP gene family , which provides valuable information for understanding the classification and functions of the TCP genes in watermelon .


The development of flower buds inSoldanella minima grown at 15 ° or above is stopped at the stage of sporogenous cells in the anthers .

2 . Low temperature overcomes this inhibition , resulting in microsporogenesis and subsequent flowering .

Microsporogenesis must thus be considered as a phase initiated only at low temperature .

Photoperiod does not seem to playa decisive role in this process .

3 . Applied gibberellic acid substitutes for the cold requirement of the flower buds .


The behavior of naturally virulent Meloidogyne isolates toward the tomato resistance gene Mi in major tomato-growing areas in Israel was studied for the first time .

Virulence of seven selected isolates was confirmed over three successive generations on resistant ( Mi-carrying ) and susceptible ( non-Mi-carrying ) tomato cultivars .

Diagnostic markers verified the predominance of Meloidogyne javanica among virulent isolates selected on resistant tomato cultivars or rootstocks .

To better understand the determinants of nematode selection on Mi-carrying plants , reproduction of Mi-avirulent and virulent isolates Mjav1 and Mjv2 , respectively , measured as eggs per gram of root , on non-Mi-carrying , heterozygous ( Mi/mi ) and homozygous ( Mi/Mi ) genotypes was evaluated .

Although no reproduction of Mjav1 was observed on Mi/Mi genotypes , some reproduction was consistently observed on Mi/mi plants ; reproduction of Mjv2 on the homozygous and heterozygous genotypes was similar to that on susceptible cultivars , suggesting a limited quantitative effect of the Mi gene .

Histological examination of giant cells induced by Mi-virulent versus avirulent isolates confirmed the high virulence of Mjv2 on Mi/mi and Mi/Mi genotypes , allowing the formation of well-developed giant-cell systems despite the Mi gene .

Analysis of the plant defense response in tomato Mi/Mi , Mi/mi , and mi/mi genotypes to both avirulent and virulent isolates was investigated by quantitative real-time polymerase chain reaction .

Although the jasmonate (JA)-signaling pathway was clearly upregulated by avirulent and virulent isolates on the susceptible ( not carrying Mi ) and heterozygous ( Mi/mi ) plants , no change in signaling was observed in the homozygous ( Mi/Mi ) resistant line following incompatible interaction with the avirulent isolate .

Thus , similar to infection promoted by the avirulent isolate on the susceptible genotype , the Mi-virulent isolate induced the JA-dependent pathway , which might promote tomato susceptibility during the compatible interaction with the homozygous ( Mi/Mi ) resistant line .

These results have important consequences for the management of Mi resistance genes for ensuring sustainable tomato farming .


Histone acetylation is modulated through the action of histone acetyltransferases and deacetylases , which play key roles in the regulation of eukaryotic gene expression .

Previously , we have identified a yeast histone deacetylase REDUCED POTASSIUM DEPENDENCY3 ( RPD3 ) homolog , HISTONE DEACETYLASE19 ( HDA19 ) ( AtRPD3A ) , in Arabidopsis thaliana .

Here , we report further study of the expression and function of HDA19 .

Analysis of Arabidopsis plants containing the HDA19:beta-glucuronidase fusion gene revealed that HDA19 was expressed throughout the life of the plant and in most plant organs examined .

In addition , the expression of HDA19 was induced by wounding , the pathogen Alternaria brassicicola , and the plant hormones jasmonic acid and ethylene .

Using green fluorescent protein fusion , we demonstrated that HDA19 accumulated in the nuclei of Arabidopsis cells .

Overexpression of HDA19 in 35S : HDA19 plants decreased histone acetylation levels , whereas downregulation of HDA19 in HDA19-RNA interference ( RNAi ) plants increased histone acetylation levels .

In comparison with wild-type plants , 35S : HDA19 transgenic plants had increased expression of ETHYLENE RESPONSE FACTOR1 and were more resistant to the pathogen A. brassicicola .

The expression of jasmonic acid and ethylene regulated PATHOGENESIS-RELATED genes , Basic Chitinase and beta-1,3-Glucanase , was upregulated in 35S : HDA19 plants but downregulated in HDA19-RNAi plants .

Our studies provide evidence that HDA19 may regulate gene expression involved in jasmonic acid and ethylene signaling of pathogen response in Arabidopsis .


Fourteen chemically defined hydrolyzable tannins and six impure mixtures of either condensed or hydrolyzable tannins were found to inhibit the gibberellin-induced growth of light-grown dwarf pea seedlings .

The highest ratio of tannins to gibberellic acid tested ( 1000 : 1 by weight ) inhibited from 80 to 95 % of the induced growth for all tannins tested except for two monogalloyl glucose tannins which inhibited only 50 % of the induced growth .

The lowest ratio tested ( 10 : 1 ) inhibited the induced growth by less than 25 % except for the case of terchebin where 50 % inhibition was found .

The inhibition of gibberellin-induced growth was found to be completely reversed by increasing the amount of gibberellin in three cases tested .

Tannins alone did not inhibit endogenous growth of either dwarf or nondwarf pea seedlings .

Eight compounds related to tannins , including coumarin , trans-cinnamic acid , and a number of phenolic compounds were also tested as gibberellin antagonists .

Most of these compounds showed some inhibition of gibberellin-induced growth , but less than that of the tannins .

At the highest ratio ( 1000 : 1 ) the greatest inhibition was 55 % ; at the lowest ratio ( 10 : 1 ) no more than 17 % was observed .

These compounds did not inhibit endogenous growth , and the inhibition of gibberellin-induced growth could be reversed by increasing the amount of gibberellin in two cases tested .

Six chemically defined tannins were found to inhibit hypocotyl growth induced by gibberellic acid in cucumber seedlings .

Growth induced by indoleacetic acid in the same test was not inhibited .

The highest ratio of tannin to promotor tested gave strong inhibition of gibberellic acid-induced growth , but actually enhanced the growth induced by indoleacetic acid .

This difference in action suggests a specificity between the tannins and gibberellic acid .


Nitrogen dioxide ( NO(2 ) ) forms in plants under stress conditions , but little is known about its physiological functions .

Here , we explored the physiological functions of NO(2 ) in plant cells using short-term fumigation of Arabidopsis ( Arabidopsis thaliana ) for 1 h with 10 µL L(-1 ) NO(2 . ) Although leaf symptoms were absent , the expression of genes related to pathogen resistance was induced .

Fumigated plants developed basal disease resistance , or pattern-triggered immunity , against the necrotrophic fungus Botrytis cinerea and the hemibiotrophic bacterium Pseudomonas syringae Functional salicylic acid and jasmonic acid ( JA ) signaling pathways were both required for the full expression of NO(2)-induced resistance against B. cinerea An early peak of salicylic acid accumulation immediately after NO(2 ) exposure was followed by a transient accumulation of oxophytodienoic acid .

The simultaneous NO(2)-induced expression of genes involved in jasmonate biosynthesis and jasmonate catabolism resulted in the complete suppression of JA and JA-isoleucine ( JA-Ile ) accumulation , which was accompanied by a rise in the levels of their catabolic intermediates 12-OH-JA , 12-OH-JA-Ile , and 12-COOH-JA-Ile .

NO(2)-treated plants emitted the volatile monoterpene α-pinene and the sesquiterpene longifolene ( syn . junipene ) , which could function in signaling or direct defense against pathogens .

NO(2)-triggered B. cinerea resistance was dependent on enhanced early callose deposition and CYTOCHROME P450 79B2 ( CYP79B2 ) , CYP79B3 , and PHYTOALEXIN DEFICIENT3 gene functions but independent of camalexin , CYP81F2 , and 4-OH-indol-3-ylmethylglucosinolate derivatives .

In sum , exogenous NO(2 ) triggers basal pathogen resistance , pointing to a possible role for endogenous NO(2 ) in defense signaling .

Additionally , this study revealed the involvement of jasmonate catabolism and volatiles in pathogen immunity .


Ethylene responsive factors ( ERFs ) are a large family of plant-specific transcription factors that are involved in the regulation of plant development and stress responses .

However , little to nothing is known about their role in herbivore-induced defense .

We discovered a nucleus-localized ERF gene in rice ( Oryza sativa ) , OsERF3 , that was rapidly up-regulated in response to feeding by the rice striped stem borer ( SSB ) Chilo suppressalis .

Antisense and over-expression of OsERF3 revealed that it positively affects transcript levels of two mitogen-activated protein kinases ( MAPKs ) and two WRKY genes as well as concentrations of jasmonate ( JA ) , salicylate ( SA ) and the activity of trypsin protease inhibitors ( TrypPIs ) .

OsERF3 was also found to mediate the resistance of rice to SSB .

On the other hand , OsERF3 was slightly suppressed by the rice brown planthopper ( BPH ) Nilaparvata lugens ( Stål ) and increased susceptibility to this piercing sucking insect , possibly by suppressing H(2)O(2 ) biosynthesis .

We propose that OsERF3 affects early components of herbivore-induced defense responses by suppressing MAPK repressors and modulating JA , SA , ethylene and H(2)O(2 ) pathways as well as plant resistance .

Our results also illustrate that OsERF3 acts as a central switch that gears the plant 's metabolism towards an appropriate response to chewing or piercing/sucking insects .


Abscisic-acid ( ABA ) levels were determined in triticale 6A190 kernels at various stages of development from anthesis to maturity .

22 d post-anthesis and declined rapidly 12 d later .

Associated with drying of the kernel at maturity there was a rapid increase in the endogenous level of α-amylase , apparently based upon de-novo synthesis .

Simultaneously there were visible signs of degradation of the large starch grains in the starchy endosperm .

Regulation of α-amylase production in the kernel by exogenous gibberellic acid ( GA3 ) was only evident in the almost mature kernel ( 30 - 40 d after anthesis ) and then only if these kernels were first dried artificially .

Furthermore , little α-amylase mRNA could be detected prior to kernel maturity and water loss .

Thus , the high levels of gibberellin ( GA ) that have been found early in kernel development in cereals do not appear to control the later production of α-amylase and onset of kernel germination in the ear of triticale .

However , the presence of high levels of ABA until maturity could prevent early germination and premature production of α-amylase .

Kernels of triticale 6A190 are characteristically shrivelled and non-dormant at maturity .

The relevance of changes in the capacity of kernels to respond to and produce GA and ABA is discussed in relation to problems of harvest dormancy in cereals .


The activities of (±)-abscisic acid and a number of compounds derived from p-coumaric acid and coumarin and their interaction with gibberellic acid in the control of the elongation of the first wheat leaf are examined .

(±)-Abscisic acid strongly inhibits leaf growth in the presence as well as in the absence of gibberellic acid , but the inhibition is greater in the presence of gibberellic acid ( 3 μg/l already have an observable effect ) .

Among other compounds , only ferulic acid and coumarin significantly reduce leaf elongation , and they are effective only at high concentrations ( 1.44 · 10(-4 ) M/l ) .


The plant photoreceptor phytochrome is organised in a small gene family with phytochrome A ( phyA ) being unique , because it is specifically degraded upon activation by light .

This so called photodestruction is thought to be important for dynamic aspects of sensing such as measuring day length or shading by competitors .

Signal-triggered proteolytic degradation has emerged as central element of signal crosstalk in plants during recent years , but many of the molecular players are still unknown .

We therefore analyzed a jasmonate (JA)-deficient rice mutant , hebiba , that in several aspects resembles a mutant affected in photomorphogenesis .

In this mutant , the photodestruction of phyA is delayed as shown by in vivo spectroscopy and Western blot analysis .

Application of methyl-JA ( MeJA ) can rescue the delayed phyA photodestruction in the mutant in a time- and dose-dependent manner .

Light regulation of phyA transcripts thought to be under control of stable phytochrome B ( phyB ) is still functional .

The delayed photodestruction is accompanied by an elevated sensitivity of phytochrome-dependent growth responses to red and far-red light .


Mutant T66 was isolated from 450 mutants ( constructed with Agrobacterium tumefaciens-mediated transformation method ) of Trichoderma harzianum .

Maize seeds coated with T66 were more susceptible to Curvularia lunata when compared with those coated with wild-type ( WT ) strain .

The disease index of maize treated with T66 and WT were 62.5 and 42.1 % , respectively .

Further research showed T-DNA has inserted into the ORF of one gene , which resulted in the functional difference between WT and T66 .

The gene was cloned and named Thc6 , which encodes a novel 327 amino acid protein .

To investigate its function , we obtained knockout , complementation , and overexpression mutants of Thc6 .

Challenge inoculation studies suggested that the Thc6 overexpression mutant can reduce the disease index of maize inbred line Huangzao 4 against the leaf spot pathogen ( C. lunata ) .

Meanwhile , The Thc6 mutants were found to affect the resistance of maize inbred line Huangzao 4 against C. lunata by enhancing the activation of jasmonate-responsive genes expression .

Liquid chromatography-mass spectrometry ( LC-MS ) data further confirmed that the concentration of jasmonate in the induced maize exhibits a parallel change tendency with the expression level of defense-related genes .

Hence , the Thc6 gene could be participated in the induced resistance of maize inbred line Huangzao 4 against C. lunata infection through a jasmonic acid-dependent pathway .


The tobacco N gene , a member of the Toll-interleukin 1 homology region/nucleotide binding site/leucine-rich repeat ( TIR-NBS-LRR ) class of resistance ( R ) genes , confers resistance to tobacco mosaic virus ( TMV ) .

We used a candidate gene approach to identify known defense genes that were also involved in N signaling .

The requirement for these genes was determined by downregulating their expression using the well-established tobacco rattle virus (TRV)-based virus-induced gene silencing ( VIGS ) .

Silencing of genes encoding a mitogen-activated protein kinase ( MAPK ) NTF6/NRK1 , or an MAPK kinase ( MAPKK ) MEK1/NQK1 , attenuated N-mediated resistance to TMV .

We also found that N resistance is compromised in plants in which expression of WRKY1-WRKY3 and MYB1 transcription factors were downregulated .

In addition , suppression of jasmonic acid ( JA ) signaling component COI1 ortholog affected N function .

However , downregulation of expression of CTR1 ortholog leads to more rapid hypersensitive response ( HR ) .

The involvement of these genes in N- and other R-gene-mediated defense provides further evidence for the convergence of downstream signaling pathways of different R genes .


Ramularia leaf spot disease ( RLS ) , caused by the ascomycete fungus Ramularia collo-cygni , has emerged as a major economic disease of barley .

No substantial resistance has been identified , so far , among barley genotypes and , based on the epidemiology of the disease , a quantitative genetic determinacy of RLS has been suggested .

The relative contributions of barley and R. collo-cygni genetics to disease infection and epidemiology are practically unknown .

Here , we present an integrated genome-wide analysis of host and pathogen transcriptome landscapes identified in a sensitive barley cultivar following infection by an aggressive R. collo-cygni isolate .

We compared transcriptional responses in the infected and noninfected leaf samples in order to identify which molecular events are associated with RLS symptom development .

We found a large proportion of R. collo-cygni genes to be expressed in planta and that many were also closely associated with the infection stage .

The transition from surface to apoplastic colonization was associated with downregulation of cell wall-degrading genes and upregulation of nutrient uptake and resistance to oxidative stresses .

Interestingly , the production of secondary metabolites was dynamically regulated within the fungus , indicating that R. collo-cygni produces a diverse panel of toxic compounds according to the infection stage .

A defense response against R. collo-cygni was identified in barley at the early , asymptomatic infection and colonization stages .

We found activation of ethylene signaling , jasmonic acid signaling , and phenylpropanoid and flavonoid pathways to be highly induced , indicative of a classical response to necrotrophic pathogens .

Disease development was found to be associated with gene expression patterns similar to those found at the onset of leaf senescence , when nutrients , possibly , are used by the infecting fungus .

These analyses , combining both barley and R. collo-cygni transcript profiles , demonstrate the activation of complex transcriptional programs in both organisms .


Maize ( Zea mays L. ) suspension-cultured cells with up to 70 % less cellulose were obtained by stepwise habituation to dichlobenil ( DCB ) , a cellulose biosynthesis inhibitor .

Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by Fourier transform infrared ( FTIR ) spectroscopy .

Cell wall compositional analysis indicated that the cellulose-deficient cell walls showed an enhancement of highly branched and cross-linked arabinoxylans , as well as an increased content in ferulic acid , diferulates and p-coumaric acid , and the presence of a polymer that stained positive for phloroglucinol .

In accordance with this , cellulose-deficient cell walls showed a fivefold increase in Klason-type lignin .

Thioacidolysis/GC-MS analysis of cellulose-deficient cell walls indicated the presence of a lignin-like polymer with a Syringyl/Guaiacyl ratio of 1.45 , which differed from the sensu stricto stress-related lignin that arose in response to short-term DCB-treatments .

Gene expression analysis of these cells indicated an overexpression of genes specific for the biosynthesis of monolignol units of lignin .

A study of stress signaling pathways revealed an overexpression of some of the jasmonate signaling pathway genes , which might trigger ectopic lignification in response to cell wall integrity disruptions .

In summary , the structural plasticity of primary cell walls is proven , since a lignification process is possible in response to cellulose impoverishment .


Although the roles of salicylate ( SA ) and jasmonic acid ( JA ) have been well-characterized in Fusarium head blight (FHB)-infected cereals , the roles of other phytohormones remain more ambiguous .

Here , the association between an array of phytohormones and FHB pathogenesis in wheat is investigated .

Comprehensive profiling of endogenous hormones demonstrated altered cytokinin , gibberellic acid ( GA ) , and JA metabolism in a FHB-resistant cultivar , whereas challenge by Fusarium graminearum increased abscisic acid ( ABA ) , JA , and SA in both FHB-susceptible and -resistant cultivars .

Subsequent investigation of ABA or GA coapplication with fungal challenge increased and decreased FHB spread , respectively .

These phytohormones-induced effects may be attributed to alteration of the F. graminearum transcriptome because ABA promoted expression of early-infection genes , including hydrolases and cytoskeletal reorganization genes , while GA suppressed nitrogen metabolic gene expression .

Neither ABA nor GA elicited significant effects on F. graminearum fungal growth or sporulation in axenic conditions , nor do these phytohormones affect trichothecene gene expression , deoxynivalenol mycotoxin accumulation , or SA/JA biosynthesis in F. graminearum-challenged wheat spikes .

Finally , the combined application of GA and paclobutrazol , a Fusarium fungicide , provided additive effects on reducing FHB severity , highlighting the potential for combining fungicidal agents with select phytohormone-related treatments for management of FHB infection in wheat .


Exposure of plants to toxic concentrations of metals leads to disruption of the cellular redox status followed by an accumulation of reactive oxygen species ( ROS ) .

ROS , like hydrogen peroxide , can act as signaling molecules in the cell and induce signaling via mitogen-activated protein kinase ( MAPK ) cascades .

MAPK cascades are evolutionary conserved signal transduction modules , able to convert extracellular signals to appropriate cellular responses .

In this review , our current understanding about MAPK signaling in plant metal stress is discussed .

However , this knowledge is scarce compared to research into the role of MAPK signaling in the case of other abiotic and biotic stresses .

ROS production is a common response induced by different stresses and undiscovered analogies may exist with metal stress .

Therefore , further attention is given to MAPK signaling in other biotic and abiotic stresses and its interplay with other signaling pathways to create a framework in which the involvement of MAPK signaling in metal stress may be studied .


Plant phospholipase Ds ( PLDs ) , essential regulators of phospholipid signaling , function in multiple signal transduction cascades ; however , the mechanisms regulating PLDs in response to pathogens remain unclear .

Here , we found that Arabidopsis ( Arabidopsis thaliana ) PLDδ accumulated in cells at the entry sites of the barley powdery mildew fungus , Blumeria graminis f. sp hordei Using fluorescence recovery after photobleaching and single-molecule analysis , we observed higher PLDδ density in the plasma membrane after chitin treatment ; PLDδ also underwent rapid exocytosis .

Fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy showed that the interaction between PLDδ and the microdomain marker AtREMORIN1.3 ( AtREM1.3 ) increased in response to chitin , indicating that exocytosis facilitates rapid , efficient sorting of PLDδ into microdomains upon pathogen stimulus .

We further unveiled a trade-off between brefeldin A (BFA)-resistant and -sensitive pathways in secretion of PLDδ under diverse conditions .

Upon pathogen attack , PLDδ secretion involved syntaxin-associated VAMP721/722-mediated exocytosis sensitive to BFA .

Analysis of phosphatidic acid ( PA ) , hydrogen peroxide , and jasmonic acid ( JA ) levels and expression of related genes indicated that the relocalization of PLDδ is crucial for its activation to produce PA and initiate reactive oxygen species and JA signaling pathways .

Together , our findings revealed that the translocation of PLDδ to papillae is modulated by exocytosis , thus triggering PA-mediated signaling in plant innate immunity.plantcell;31/12/3015/FX1F1fx1 .


Plant growth and development is often regulated by the interaction of environmental factors such as light and various phytohormones .

Arabidopsis FAR-RED INSENSITIVE 219 (FIN219)/JASMONATE RESISTANT 1 ( JAR1 ) participates in phytochrome A-mediated far-red ( FR ) light signaling and interacts with different light signaling regulators .

FIN219/JAR1 is a jasmonic acid (JA)-conjugating enzyme responsible for the formation of JA-isoleucine .

However , how FIN219/JAR1 integrates FR light and JA signaling remains largely unknown .

We used a microarray approach to dissect the effect of fin219 mutation on the interaction of FR light and JA signaling .

The fin219 - 2 mutant was less sensitive than the wild type to various concentrations of methyl jasmonate ( MeJA ) under low and high FR light .

High FR light reduced the sensitivity of Arabidopsis seedlings to MeJA likely through FIN219 .

Intriguingly , in response to MeJA , FIN219 levels showed a negative feedback regulation .

Further microarray assay revealed that FR light could regulate gene expression by FIN219-dependent or -independent pathways .

The expression profiles affected in fin219 - 2 indicated that FIN219/JAR1 plays a critical role in the integration of multiple hormone-related signaling .

In particular , FIN219 regulates a number of transcription factors ( TFs ) , including 94 basic helix-loop-helix ( bHLH ) TFs , in response to FR light and MeJA .

Loss-of-function mutants of some bHLH TFs affected by FIN219 showed altered responses to MeJA in the regulation of hypocotyl and root elongation .

Thus , FIN219/JAR1 is tightly regulated in response to exogenous MeJA .

It also interacts with multiple plant hormones to modulate hypocotyl and root elongation of Arabidopsis seedlings likely by regulating a group of TFs .


The role of ethylene ( ET ) signaling in the responses of two hybrid aspen ( Populus tremula L. x P. tremuloides Michx . ) clones to chronic ozone ( O(3 ) ; 75 nL L(-1 ) ) was investigated .

The hormonal responses differed between the clones ; the O(3)-sensitive clone 51 had higher ET evolution than the tolerant clone 200 during the exposure , whereas the free salicylic acid concentration in clone 200 was higher than in clone 51 .

The cellular redox status , measured as glutathione redox balance , did not differ between the clones suggesting that the O(3 ) lesions were not a result of deficient antioxidative capacity .

The buildup of salicylic acid during chronic O(3 ) exposure might have prevented the up-regulation of ET biosynthesis in clone 200 .

Blocking of ET perception with 1-methylcyclopropene protected both clones from the decrease in net photosynthesis during chronic exposure to O(3 ) .

After a pretreatment with low O(3 ) for 9 d , an acute 1.5-fold O(3 ) elevation caused necrosis in the O(3)-sensitive clone 51 , which increased substantially when ET perception was blocked .

The results suggest that in hybrid aspen , ET signaling had a dual role depending on the severity of the stress .

ET accelerated leaf senescence under low O(3 ) , but under acute O(3 ) elevation , ET signaling seemed to be required for protection from necrotic cell death .


Ca2 + and calmodulin ( CaM ) , a key Ca2 + sensor in all eukaryotes , have been implicated in defense responses in plants .

To elucidate the role of Ca2 + and CaM in defense signaling , we used 35S-labeled CaM to screen expression libraries prepared from tissues that were either treated with an elicitor derived from Phytophthora megasperma or infected with Pseudomonas syringae pv . tabaci .

Nineteen cDNAs that encode the same protein , pathogen-induced CaM-binding protein ( PICBP ) , were isolated .

The PICBP fusion proteins bound 35S-CaM , horseradish peroxidase-labeled CaM and CaM-Sepharose in the presence of Ca2 + whereas EGTA , a Ca2 + chelator , abolished binding , confirming that PICBP binds CaM in a Ca2 + -dependent manner .

Using a series of bacterially expressed truncated versions of PICBP , four CaM-binding domains , with a potential CaM-binding consensus sequence of WSNLKKVILLKRFVKSL , were identified .

The deduced PICBP protein sequence is rich in leucine residues and contains three classes of repeats .

The PICBP gene is differentially expressed in tissues with the highest expression in stem .

The expression of PICBP in Arabidopsis was induced in response to avirulent Pseudomonas syringae pv . tomato carrying avrRpm1 .

Furthermore , PICBP is constitutively expressed in the Arabidopsis accelerated cell death2 - 2 mutant .

The expression of PICBP in bean leaves was also induced after inoculation with avirulent and non-pathogenic bacterial strains .

In addition , the hrp1 mutant of Pseudomonas syringae pv . tabaci and inducers of plant defense such as salicylic acid , hydrogen peroxide and a fungal elicitor induced PICBP expression in bean .

Our data suggest a role for PICBP in Ca2 + -mediated defense signaling and cell-death .

Furthermore , PICBP is the first identified CBP in eukaryotes with four Ca2 + -dependent CaM-binding domains .


Black pepper ( Piper nigrum L. ) is one of the most popular and oldest spices in the world with culinary uses and various pharmacological properties .

In order to satisfy the growing worldwide demand for black pepper , improved productivity of pepper is highly desirable .

A primary constraint in black pepper production is the non-synchronous nature of flower development and non-uniform fruit ripening within a spike .

The uneven ripening of pepper berries results in a high labour requirement for selective harvesting contributes to low productivity and affects the quality of the pepper products .

In Malaysia , there are a few recommended varieties for black pepper planting , each having some limitations in addition to the useful characteristics .

Therefore , a comparative study of different black pepper varieties will provide a better understanding of the mechanisms regulates fruit development and ripening .

Plant hormones are known to influence the fruit development process and their roles in black pepper flower and fruit development were inferred based on the probe-based gene expression analysis and the quantification of the multiple plant hormones using high-performance liquid chromatography coupled to tandem mass spectrometry ( HPLC-MS/MS ) .

In this study , jasmonic acid and salicylic acid were found to play roles in flowering and fruit setting , whereas auxin , gibberellin and cytokinins are important for fruit growth .

Abscisic acid has positive role in fruit maturation and ripening in the development process .

Distinct pattern of plant hormones related gene expression profiles with the hormones accumulation profiles suggested a complex network of regulation is involved in the signaling process and crosstalk between plant hormones was another layer of regulation in the black pepper fruit development mechanisms .

The current study provides clues to help in elucidating the timing of the action of each specific plant hormone during fruit development and ripening which could be applied to enhance our ability to control the ripening process , leading to improving procedures for the production and post-harvest handling of pepper fruits .


Jasmonate ( JA ) signaling is a key mediator of plant development and defense which arose during plants transition from an aqueous to terrestrial environment .

Elucidating the evolution of JA signaling is important for understanding plant development , defense , and production of specialized metabolites .

The lineage of key protein domains characterizing JA signaling factors was traced to identify the origins of CORONITINE INSENSITIVE 1 ( COI1 ) , JASMONATE ZIM-DOMAIN ( JAZ ) , NOVEL INTERACTOR OF JAZ , MYC2 , TOPLESS , and MEDIATOR SUBUNIT 25 .

Charophytes do not possess genes encoding key JA signaling components , including COI1 , JAZ , MYC2 , and the JAZ-interacting bHLH factors , yet their orthologs are present in bryophytes .

TIFY family genes were found in charophyta and chlorophya algae .

JAZs evolved from ZIM genes of the TIFY family through changes to several key amino acids .

Dating placed the origin of JA signaling 515 to 473 million years ago during the middle Cambrian to early Ordovician periods .

This time is known for rapid biodiversification and mass extinction events .

An increased predation from the diversifying and changing fauna may have driven evolution of JA signaling and plant defense .


Redox processes regulate plant/insect responses , but the precise roles of environmental triggers and specific molecular components remain poorly defined .

Aphid fecundity and plant responses were therefore measured in Arabidopsis thaliana mutants deficient in either catalase 2 ( cat2 ) , different protein phosphatase 2A ( PP2A ) subunits or glutathione ( cad2 , pad2 , and clt1 ) under either moderate ( 250 μmol m(-2 ) s(-1 ) ) or high ( 800 μmol m(-2 ) s(-1 ) ) light .

Aphid fecundity was decreased in pp2a-b'γ , cat2 and the cat2 pp2a-b'γ double mutants relative to the wild type under moderate irradiance .

High light decreased aphid numbers in all genotypes except for cat2 .

Aphid fecundity was similar in the cat2 and glutathione- , phytoalexin- , and glucosinolate-deficient cat2cad2 double mutants under both irradiances .

Aphid-induced increases in transcripts encoding the abscisic acid-related ARABIDOPSIS ZINC-FINGER PROTEIN 1 transcription factor were observed only under moderate light .

Conversely , aphid induced increases in transcripts encoding the jasmonate-synthesis enzyme ALLENE OXIDE CYCLASE 3 was observed in all genotypes only under high light .

Aphid-induced increases in REDOX RESPONSIVE TRANSCRIPTION FACTOR 1 mRNAs were observed in all genotypes except pp2a-b'ζ1 - 1 under both irradiances .

Aphid fecundity is therefore regulated by cellular redox signalling that is mediated , at least in part , through PP2A-dependent mitochondria to nucleus signalling pathways .


The hemibiotrophic fungus Zymoseptoria tritici causes Septoria tritici blotch disease of wheat ( Triticum aestivum ) .

Pathogen reproduction on wheat occurs without cell penetration , suggesting that dynamic and intimate intercellular communication occurs between fungus and plant throughout the disease cycle .

We used deep RNA sequencing and metabolomics to investigate the physiology of plant and pathogen throughout an asexual reproductive cycle of Z. tritici on wheat leaves .

Over 3,000 pathogen genes , more than 7,000 wheat genes , and more than 300 metabolites were differentially regulated .

Intriguingly , individual fungal chromosomes contributed unequally to the overall gene expression changes .

Early transcriptional down-regulation of putative host defense genes was detected in inoculated leaves .

There was little evidence for fungal nutrient acquisition from the plant throughout symptomless colonization by Z. tritici , which may instead be utilizing lipid and fatty acid stores for growth .

However , the fungus then subsequently manipulated specific plant carbohydrates , including fructan metabolites , during the switch to necrotrophic growth and reproduction .

This switch coincided with increased expression of jasmonic acid biosynthesis genes and large-scale activation of other plant defense responses .

Fungal genes encoding putative secondary metabolite clusters and secreted effector proteins were identified with distinct infection phase-specific expression patterns , although functional analysis suggested that many have overlapping/redundant functions in virulence .

The pathogenic lifestyle of Z. tritici on wheat revealed through this study , involving initial defense suppression by a slow-growing extracellular and nutritionally limited pathogen followed by defense ( hyper ) activation during reproduction , reveals a subtle modification of the conceptual definition of hemibiotrophic plant infection .


Wilt caused by Verticillium dahliae significantly reduces cotton yields , as host resistance in commercially cultivated Gossypium species is lacking .

Understanding the molecular basis of disease resistance in non-commercial Gossypium species could galvanize the development of Verticillium wilt resistance in cultivated species .

Nucleotide-binding site leucine-rich repeat ( NBS-LRR ) proteins play a central role in plant defence against pathogens .

In this study , we focused on the relationship between a locus enriched with eight NBS-LRR genes and Verticillium wilt resistance in G. barbadense .

Independent virus-induced gene silencing of each of the eight NBS-LRR genes in G. barbadense cultivar Hai 7124 revealed that silencing of GbaNA1 alone compromised the resistance of G. barbadense to V. dahliae isolate Vd991 .

In cultivar Hai 7124 , GbaNA1 could be induced by V. dahliae isolate Vd991 and by ethylene , jasmonic acid and salicylic acid .

Nuclear protein localization of GbaNA1 was demonstrated by transient expression .

Sequencing of the GbaNA1 orthologue in nine G. hirsutum accessions revealed that all carried a non-functional allele , caused by a premature peptide truncation .

In addition , all 10 G. barbadense and nine G. hirsutum accessions tested carried a full-length ( ∼1140 amino acids ) homologue of the V. dahliae race 1 resistance gene Gbve1 , although some sequence polymorphisms were observed .

Verticillium dahliae Vd991 is a non-race 1 isolate that lacks the Ave1 gene .

Thus , the resistance imparted by GbaNA1 appears to be mediated by a mechanism distinct from recognition of the fungal effector Ave1 .


Poplar trees synthesize flavan-3-ols ( catechin and proanthocyanidins ) as a defense against foliar rust fungi , but the regulation of this defense response is poorly understood .

Here , we investigated the role of hormones in regulating flavan-3-ol accumulation in poplar during rust infection .

We profiled levels of defense hormones , signaling genes , and flavan-3-ol metabolites in black poplar leaves at different stages of rust infection .

Hormone levels were manipulated by external sprays , genetic engineering , and drought to reveal their role in rust fungal defenses .

Levels of salicylic acid ( SA ) , jasmonic acid , and abscisic acid increased in rust-infected leaves and activated downstream signaling , with SA levels correlating closely with those of flavan-3-ols .

Pretreatment with the SA analog benzothiadiazole increased flavan-3-ol accumulation by activating the MYB-bHLH-WD40 complex and reduced rust proliferation .

Furthermore , transgenic poplar lines overproducing SA exhibited higher amounts of flavan-3-ols constitutively via the same transcriptional activation mechanism .

These findings suggest a strong association among SA , flavan-3-ol biosynthesis , and rust resistance in poplars .

Abscisic acid also promoted poplar defense against rust infection , but likely through stomatal immunity independent of flavan-3-ols .

Jasmonic acid did not confer any apparent defense responses to the fungal pathogen .

We conclude that SA activates flavan-3-ol biosynthesis in poplar against rust infection .


Acer pseudoplatanus seeds are characterized by a deep physiological embryo dormancy that requires a few weeks of cold stratification in order to promote germination .

Understanding the function of proteins and their related metabolic pathways , in conjunction with the plant hormones implicated in the breaking of seed dormancy , would expand our knowledge pertaining to this process .

In this study , a proteomic approach was used to analyze the changes occurring in seeds in response to cold stratification , which leads to dormancy release .

In addition , the involvement of abscisic ( ABA ) and gibberellic acids ( GA ) was also examined .

Fifty-three proteins showing significant changes were identified by mass spectrometry .

An effect of ABA on protein variation was observed at the beginning of stratification , while the influence of GA on protein abundance was observed during the middle phase of stratification .

The majority of proteins associated with dormancy breaking in the presence of only water , and also ABA or GA , were classified as being involved in metabolism and genetic information processing .

For metabolic-related proteins , the effect of ABA on protein abundance was stimulatory for half of the proteins and inhibitory for half of the proteins .

On the other hand , the effect on genetic information processing related proteins was stimulatory .

GA was found to upregulate both metabolic-related and genetic information processing-related proteins .

While seed dormancy breaking depends on proteins involved in a variety of processes , proteins associated with methionine metabolism ( adenosine kinase , methionine synthase ) and glycine-rich RNA binding proteins appear to be of particular importance .


Ginseng is one of the most important plants in oriental medicine .

The pharmacological effects of this medicinal herb are mostly correlated to the major bioactive triterpene saponin , called ginsenoside .

Due to the long cultivation period of ginseng and increased ginsenoside level in aged root , we need to develop strategies to increase ginseng productivity in cell and tissue culture in a faster way .

Elicitation is already considered to improve the yield of this valuable secondary metabolite ; especially , different types , timings , and durations of elicitation could affect the ginsenoside production and heterogeneity .

Activation of ginsenoside biosynthetic genes and ginsenoside accumulation mediated by elicitor-induced signaling molecules would be helpful for commercial production of individual ginsenosides .

Jasmonic acid is the well-known signaling molecule which mainly involved in ginsenoside accumulation .

Ca(2 + ) spiking and reactive oxygen species , nitric oxide , and ethylene production are other messengers which mediate production of ginsenoside .

This review highlights the elicitation strategies for production of the ginsenoside based on the principle of putative signal transduction pathways .


Calcium-dependent protein kinases ( CPKs ) play important roles in multiple signal transduction pathways but the precise role of individual CPK is largely unknown .

We isolated two cDNAs encoding two CPK isoforms ( Cicer arietinum CPKs-CaCPK1 and CaCPK2 ) of chickpea .

Their expression in various organs and in response to various phytohormones , and dehydration , high salt stress and fungal spore in excised leaves as well as localization in leaf and stem tissues were analyzed in this study .

CaCPK1 protein and its activity were ubiquitous in all tissues examined .

In contrast , CaCPK2 transcript , CaCPK2 protein and its activity were almost undetectable in flowers and fruits .

Both CaCPK1 and CaCPK2 transcripts and proteins were abundant in roots but in minor quantities in leaves and stems .

Of the three phytohormones tested , viz . indole-3-acetic acid ( IAA ) , gibberellin ( GA(3 ) ) and benzyladenine ( BA ) , only BA increased both CaCPK1 and CaCPK2 transcripts , proteins and their activities .

GA(3 ) induced accumulation of CaCPK2 transcript and protein but CaCPK1 remained unaffected .

The expression of CaCPK1 and CaCPK2 in leaves was enhanced in response to high salt stress .

Treatments with Aspergillus sp. spores increased expression of CaCPK1 in chickpea leaf tissue but had no effect on CaCPK2 .

Excised leaves subjected to dehydration showed increase in CaCPK2 expression but not in CaCPK1 .

Both isoforms were located in the plasma membrane ( PM ) and chloroplast membrane of leaf mesophyll cells as well as in the PM of stem xylem parenchyma cells .

These results suggest specific roles for CaCPK isoforms in phytohormone/defense/stress signaling pathways .


The pentose phosphate pathway ( PPP ) plays an important role in plant growth and development , and plant responses to biotic and abiotic stresses .

Yet , whether the PPP regulates plant defenses against herbivorous insects remains unclear .

In this study , we cloned a rice cytosolic 6-phosphogluconate dehydrogenase gene , Os6PGDH1 , which encodes the key enzyme catalyzing the third step in the reaction involving the oxidative phase of the PPP , and explored its role in rice defenses induced by brown planthopper ( BPH ) Nilaparvata lugens .

Levels of Os6PGDH1 transcripts were detected in all five examined tissues , with the highest in outer leaf sheaths and lowest in inner leaf sheaths .

Os6PGDH1 expression was strongly induced by mechanical wounding , infestation of gravid BPH females , and jasmonic acid ( JA ) treatment .

Overexpressing Os6PGDH1 ( oe6PGDH ) decreased the height of rice plants and the mass of the aboveground part of plants , but slightly increased the length of plant roots .

In addition , the overexpression of Os6PGDH1 enhanced levels of BPH-induced JA , jasmonoyl-isoleucine ( JA-Ile ) , and H(2)O(2 ) , but decreased BPH-induced levels of ethylene .

Bioassays revealed that gravid BPH females preferred to feed and lay eggs on wild-type ( WT ) plants over oe6PGDH plants ; moreover , the hatching rate of BPH eggs raised on oe6PGDH plants and the fecundity of BPH females fed on these were significantly lower than the eggs and the females raised and fed on WT plants .

Taken together , these results indicate that Os6PGDH1 plays a pivotal role not only in rice growth but also in the resistance of rice to BPH by modulating JA , ethylene , and H(2)O(2 ) pathways .


The plant hormone ethylene is involved in many physiological processes , including plant growth , development and senescence .

Ethylene also plays a pivotal role in plant response or adaptation under biotic and abiotic stress conditions .

In plants , ethylene production often enhances the tolerance to sub-optimal environmental conditions .

This role is particularly important from both ecological and agricultural point of views .

Among the abiotic stresses , the role of ethylene in plants under nutrient stress conditions has not been completely investigated .

In literature few reports are available on the interaction among ethylene and macro- or micro-nutrients .

However , the published works clearly demonstrated that several mineral nutrients largely affect ethylene biosynthesis and perception with a strong influence on plant physiology .

The aim of this review is to revisit the old findings and recent advances of knowledge regarding the sub-optimal nutrient conditions on the effect of ethylene biosynthesis and perception in plants .

The effect of deficiency or excess of the single macronutrient or micronutrient on the ethylene pathway and plant responses are reviewed and discussed .

The synergistic and antagonist effect of the different mineral nutrients on ethylene plant responses is critically analyzed .

Moreover , this review highlights the status of information between nutritional stresses and plant response , emphasizing the topics that should be further investigated .


Solanum laciniatum Aiton treated with Gibberellic acid ( GA3 ) , [2-chloroethyl]-trimethyl ammonium chloride ( CCC ) , and their combinations at early and late stages of growth showed that early application of 2000 ppm CCC produced the greatest stem , leaves , and whole plant dry weight , followed by the combination of early application of 1000 ppm CCC and late application of 100 ppm GA3 ; whereas all GA3 treatments decreased the dry weight production compared with the controls .

Regarding the glyco-alkaloids , the highest percentage was obtained from the whole plant by early applications of both strengths of GA3 compared with other treatments or the controls .

On the other hand , early application of 1000 ppm CCC and also late application of 50 ppm GA3 when combined with early application of either 1000 ppm or 2000 ppm CCC produced greater alkaloid percentage yields in stem , leaves , and whole plants more than other treatments or the controls .

However , early application of 2000 ppm CCC produced the highest content of alkaloids in leaves and whole plants ; this was followed by yields from early application of 2000 ppm CCC and 50 ppm GA3 ; yields from early application of 100 ppm GA3 and 1000 ppm CCC ; and yields from early application of 1000 ppm CCC + 50 ppm GA3 .