slotreck/pickle huggingface dataset:
Studies of the singlet oxygen ( (1)O2)-overproducing flu and chlorina1 ( ch1 ) mutants of Arabidopsis ( Arabidopsis thaliana ) have shown that (1)O2-induced changes in gene expression can lead to either programmed cell death ( PCD ) or acclimation . A transcriptomic analysis of the ch1 mutant has allowed the identification of genes whose expression is specifically affected by each phenomenon . One such gene is OXIDATIVE SIGNAL INDUCIBLE1 ( OXI1 ) encoding an AGC kinase that was noticeably induced by excess light energy and (1)O2 stress conditions leading to cell death . Photo-induced oxidative damage and cell death were drastically reduced in the OXI1 null mutant ( oxi1 ) and in the double mutant ch1*oxi1 compared with the wild type and the ch1 single mutant , respectively . This occurred without any changes in the production rate of (1)O2 but was cancelled by exogenous applications of the phytohormone jasmonate . OXI1-mediated (1)O2 signaling appeared to operate through a different pathway from the previously characterized OXI1-dependent response to pathogens and H2O2 and was found to be independent of the EXECUTER proteins . In high-light-stressed plants , the oxi1 mutation was associated with reduced jasmonate levels and with the up-regulation of genes encoding negative regulators of jasmonate signaling and PCD . Our results show that OXI1 is a new regulator of (1)O2-induced PCD , likely acting upstream of jasmonate .
The goal of this study was to determine whether the application of gibberellic acid ( GA(3 ) ) to seeds of common wheat varieties with different vernalization and photoperiod requirements affects the transition from vegetative to generative stage . Three varieties of wheat with different photoperiod sensitivities and vernalization were selected for the experiment-the winter varieties , Mironovskaya and Bezostaya , and the spring variety , Sirael . Seeds were treated with different concentrations of GA(3 ) and plants were grown under long-day conditions with monitoring of their photosynthetic activity ( F(v)/F(m ) , P(n ) , E , g(s ) ) . We monitored the activity of the photosynthetic apparatus by checking the plants to see if they were growing properly . The phenological stages of the wheat species were checked for indications of a transition from the vegetative to the generative stage . Selected concentrations of GA(3 ) had no effect on the compensation of the vernalization process ( transition to the generative phase ) . Chlorophyll fluorescence was one of the factors for monitoring stress . The variety , Bezostaya , is similar to the spring variety , Sirael , in its trends and values . The growth conditions of Bezostaya and Sirael were not affected by the activity of the photosynthetic apparatus . The development of growing points in winter varieties occurred at the prolonged single ridge stage . The spring variety reached the stage of head emergence after sixty days of growth ( changes to the flowering phase did not appear in winter wheat ) . Application of GA(3 ) to the seeds had no effect on the transition of the growing point to the double-ridge generative stage . The present study highlights the priming effect of GA(3 ) on seeds of common wheat varieties with different vernalization and photoperiod requirements as it affected the transition from vegetative to generative stage .
Arbuscular mycorrhizal ( AM ) symbioses are mutualistic associations between soil fungi and most vascular plants . Modulation of the hormonal and transcriptional profiles , including changes related to defense signalling , has been reported in many host plants during AM symbioses . These changes have been often related to the improved stress tolerance common in mycorrhizal plants . However , results on the alterations in phytohormones content and their role on the symbiosis are controversial . Here , an integrative analysis of the response of phylogenetically diverse plants ( i.e. , tomato , soybean , and maize ) to two mycorrhizal fungi -Funneliformis mosseae and Rhizophagus irregularis- was performed . The analysis of the defense-related hormones salicylic acid , abscisic acid , and jasmonates , and the expression of marker genes of the pathways they regulate , revealed significant changes in the roots of mycorrhizal plants . These changes depended on both the plant and the AM fungus ( AMF ) involved . However , general trends can be identified : roots associated with the most effective colonizer R. irregularis showed fewer changes in these defense-related traits , while the colonization by F. mosseae led to significant modifications in all plants tested . The up-regulation of the jasmonate pathway by F. mosseae was found to be highly conserved among the different plant species , suggesting an important role of jasmonates during this AM interaction . Our study evidences a strong influence of the AMF genotype on the modulation of host defense signalling , and offers hints on the role of these changes in the symbiosis .
The synthesis of proteinase inhibitor proteins in response to wounding is a defensive response against pest and pathogen attacks . Wounding of leaves results in the release of a mobile wound signal which induces proteinase inhibitor synthesis throughout the plant . The signal transduction pathway regulating this response is not fully understood , but several compounds have been identified which are capable of inducing proteinase inhibitor synthesis in tomato and potato leaves . These compounds include cell wall fragments of both plant and pathogen origin [ 1 - 3 ] , abscisic acid [ 4 ] , jasmonic acid [ 5 ] and , most recently , an 18-amino-acid polypeptide , called systemin , isolated from tomato leaves [ 6 ] . In this chapter , we describe the properties of systemin and its precursor prosystemin , and we summarize the evidence supporting a role for systemin as an initial signal that regulates proteinase inhibitor synthesis in response to wounding .
We studied the localization of 6-phosphogluconate dehydrogenase ( PGD ) isoforms of Arabidopsis ( Arabidopsis thaliana ) . Similar polypeptide lengths of PGD1 , PGD2 , and PGD3 obscured which isoform may represent the cytosolic and/or plastidic enzyme plus whether PGD2 with a peroxisomal targeting motif also might target plastids . Reporter-fusion analyses in protoplasts revealed that , with a free N terminus , PGD1 and PGD3 accumulate in the cytosol and chloroplasts , whereas PGD2 remains in the cytosol . Mutagenesis of a conserved second ATG enhanced the plastidic localization of PGD1 and PGD3 but not PGD2 . Amino-terminal deletions of PGD2 fusions with a free C terminus resulted in peroxisomal import after dimerization , and PGD2 could be immunodetected in purified peroxisomes . Repeated selfing of pgd2 transfer (T-)DNA alleles yielded no homozygous mutants , although siliques and seeds of heterozygous plants developed normally . Detailed analyses of the C-terminally truncated PGD2 - 1 protein showed that peroxisomal import and catalytic activity are abolished . Reciprocal backcrosses of pgd2 - 1 suggested that missing PGD activity in peroxisomes primarily affects the male gametophyte . Tetrad analyses in the quartet1 - 2 background revealed that pgd2 - 1 pollen is vital and in vitro germination normal , but pollen tube growth inside stylar tissues appeared less directed . Mutual gametophytic sterility was overcome by complementation with a genomic construct but not with a version lacking the first ATG . These analyses showed that peroxisomal PGD2 activity is required for guided growth of the male gametophytes and pollen tube-ovule interaction . Our report finally demonstrates an essential role of oxidative pentose-phosphate pathway reactions in peroxisomes , likely needed to sustain critical levels of nitric oxide and/or jasmonic acid , whose biosynthesis both depend on NADPH provision .
Rising atmospheric CO2 concentrations can affect the induced defense of plants against herbivory by chewing insects , but little is known about whether elevated CO2 can change the inducible defense of plants against herbivory by aphids , which are phloem-sucking rather than tissue-chewing insects . Interactions between the green peach aphid Myzus persicae and four isogenic Arabidopsis thaliana genotypes including wild type and three induced defense pathway deficient mutants were examined under ambient and elevated CO2 . Our data showed that elevated CO2 increased the population abundance of peach aphid when reared on wild type and SA-deficient mutant plants . Regardless of aphid infestation , elevated CO2 decreased the jasmonic acid ( JA ) but increased the salicylic acid ( SA ) level in wild-type plants . In addition , elevated CO2 increased SA level in SA-deficient mutant while did not change the JA level in JA-deficient mutant . Pathway enrichment analysis based on high-throughput transcriptome sequencing suggested that CO2 level , aphid infestation , and their interactions ( respectively ) altered plant defense pathways . Furthermore , qPCR results showed that elevated CO2 up-regulated the expression of SA-dependent defense genes but down-regulated the expression of JA/ethylene-dependent defense genes in wild-type plants infested by aphids . The current study indicated that elevated CO2 tended to enhance the ineffective defense-SA signaling pathway and to reduce the effective defense-JA signaling pathway against aphids , which resulted in increased aphid numbers .
Plastids are the central orchestrators of the early and late responses to wounding and herbivory in plants . This organelle houses some of the most important enzymes involved in the biogenesis of intra and extracellular signals that mediate defense responses against these stresses . Among these enzymes are the ones initiating the biosynthesis of oxylipins [ e.g. , jasmonic acid ( JA ) and C(6 ) volatiles ] , terpenoid volatiles and phenolic compounds , including both volatile [ e.g. , methylsalicylate ( MeSA ) ] and non-volatile compounds [ e.g. , salicylic acid ( SA ) ] . Plastids also play a major role in orchestrating changes in primary metabolism during herbivory and thereby in the reallocation of carbon and nitrogen to different functions in response to herbivory . How the primary stress signals generated by mechanical damage and herbivory reach the plastid to activate the rapid synthesis of these signal molecules is at present largely unknown .
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 . Op14 - 3 - 3 has high homology with other 14 - 3 - 3 from Caryophyllales . 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 .