slotreck/pickle huggingface dataset:
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 .
1 . 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 . ABA reached a maximum at ca . 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 .