slotreck/pickle huggingface dataset:
Fusarium species cause serious diseases in cereal staple food crops such as wheat and maize . Currently , the mechanisms underlying resistance to Fusarium-caused diseases are still largely unknown . In the present study , we employed a combined proteomic and transcriptomic approach to investigate wheat genes responding to F. graminearum infection that causes Fusarium head blight ( FHB ) . We found a total of 163 genes and 37 proteins that were induced by infection . These genes and proteins were associated with signaling pathways mediated by salicylic acid ( SA ) , jasmonic acid ( JA ) , ethylene ( ET ) , calcium ions , phosphatidic acid ( PA ) , as well as with reactive oxygen species ( ROS ) production and scavenging , antimicrobial compound synthesis , detoxification , and cell wall fortification . We compared the time-course expression profiles between FHB-resistant Wangshuibai plants and susceptible Meh0106 mutant plants of a selected set of genes that are critical to the plants ' resistance and defense reactions . A biphasic phenomenon was observed during the first 24 h after inoculation ( hai ) in the resistant plants . The SA and Ca(2 + ) signaling pathways were activated within 6 hai followed by the JA mediated defense signaling activated around 12 hai . ET signaling was activated between these two phases . Genes for PA and ROS synthesis were induced during the SA and JA phases , respectively . The delayed activation of the SA defense pathway in the mutant was associated with its susceptibility . After F. graminearum infection , the endogenous contents of SA and JA in Wangshuibai and the mutant changed in a manner similar to the investigated genes corresponding to the individual pathways . A few genes for resistance-related cell modification and phytoalexin production were also identified . This study provided important clues for designing strategies to curb diseases caused by Fusarium .
In tobacco , two mitogen-activated protein ( MAP ) kinases , designated salicylic acid (SA)-induced protein kinase ( SIPK ) and wounding-induced protein kinase ( WIPK ) are activated in a disease resistance-specific manner following pathogen infection or elicitor treatment . To investigate whether nitric oxide ( NO ) , SA , ethylene , or jasmonic acid ( JA ) are involved in this phenomenon , the ability of these defense signals to activate these kinases was assessed . Both NO and SA activated SIPK ; however , they did not activate WIPK . Additional analyses with transgenic NahG tobacco revealed that SA is required for the NO-mediated induction of SIPK . Neither JA nor ethylene activated SIPK or WIPK . Thus , SIPK may function downstream of SA in the NO signaling pathway for defense responses , while the signals responsible for resistance-associated WIPK activation have yet to be determined .
The major programs of gene expression during late embryogenesis are the muturation or reserve accumulation program and , after ovule abscission , the postabscission program that is composed largely of Lea and LeaA mRNAs that probably encode desiccation protectants . There are diverse opinions about the developmental regulators of these programs . Several candidates are evaluated here by measuring , in cultured embryos , the accumulation kinetics of cloned mRNAs specifically expressed in the normal maturation , postabscission , or germination programs of cotton . Maturation-stage embryos both terminate the maturation program and induce the postabscission program after excision and culture , just as they do later in the plant after ovule abscission . However , they also induce simultaneously the germination program and are thus different from any normal stage of embryo development or germination . The developmental induction of the postabscission program in culture does not require exogenous abscisic acid , but its expression is enhanced by precocious desiccation or culture on abscisic acid or high osmoticum , probably by an environmentally responsive mechanism that normally operates during germination . Normal desiccation does not control any of these programs because the embryo acquires all of the characteristics of a mature embryo before it desiccates . These and other results suggest regulation of normal embryogenesis by a maternal maturation factor , a postabscission factor , and the postabscission program .
SPINDLY ( SPY ) is an important regulator of plant development , and consists of an N-half tetratricopeptide repeat ( TPR ) domain containing 10 TPR motifs and a C-half catalytic domain , similar to O-GlcNAc transferase ( OGT ) of animals . The best characterised role of SPY is a negative regulator of GA signalling , and all known spy alleles have been isolated based on increased GA response . Of the eight alleles that directly affect the TPR domain , all alter TPRs 6 , 8 and/or 9 . To test the hypothesis that a subset of TPRs , including 6 , 8 and 9 , are both essential and sufficient for the regulation of GA response , we overexpressed the full-length barley ( Hordeum vulgare L. ) SPY protein ( HvSPY ) and several deletion mutants in barley aleurone cells and in Arabidopsis wild type ( WT ) and spy-4 plants . Transient assays in barley aleurone cells , that also express endogenous HvSPY , demonstrated that introduced HvSPY and HvTPR inhibited GA(3)-induced alpha-amylase expression . With the exception of HvSPYDelta1 - 5 , the other deletion proteins were partially active in the barley assay , including HvSPYDelta6 - 9 which lacks TPRs 6 , 8 and 9 . In Arabidopsis , analysis of seed germination under a range of conditions revealed that 35S : HvSPY increased seed dormancy . Hvspy-2 , which lacks parts of the eighth and ninth TPRs , was able to partially complement all aspects of the spy-4 phenotype . In the presence of AtSPY , 35S : HvTPR caused some phenotypes consistent with a decrease in GA signalling , including increased seed sensitivity to paclobutrazol and delayed flowering . These plants also possessed distorted leaf morphology and altered epidermal cell shape . Thus , despite genetic analysis demonstrating that TPRs 6 , 8 and 9 are required for regulation of GA signalling , our results suggest that these TPRs are neither absolutely essential nor sufficient for SPY activity .
The citrus rootstocks sour orange and Cleopatra mandarin display differential resistance against Tetranychus urticae . Sour orange plants support reduced oviposition , growth rates and damage compared with Cleopatra mandarin plants . Jasmonic acid signalling and flavonoid accumulation have been revealed as key mechanisms for the enhanced resistance of sour orange plants . In this study , we observed that the release of T. urticae herbivore-induced plant volatiles ( HIPVs ) from sour orange plants has a marked repellent effect on conspecific mites associated with the production of the terpenes α-ocimene , α-farnesene , pinene and d-limonene , and the green leaf volatile 4-hydroxy-4-methyl-2-pentanone . By contrast , T. urticae HIPVs from Cleopatra mandarin plants promote conspecific mite attraction associated with an increase in ( 2-butoxyethoxy ) ethanol , benzaldehyde and methyl salicylate levels . HIPVs released from sour orange plants following T. urticae infestation induce resistance in Cleopatra mandarin plants , thereby reducing oviposition rates and stimulating the oxylipin biosynthetic gene lipoxygenase2 ( LOX2 ) . Cleopatra HIPVs do not affect the response to T. urticae of these rootstocks . We conclude that sour orange plants promote herbivore-induced resistance in Cleopatra mandarin plants and , despite the weak basal resistance of these rootstocks , herbivore resistance can be induced through the combination of HIPVs , such as α-ocimene and d-limonene .
Proteomics has contributed to defining the specific functions of genes and proteins involved in plant-pathogen interactions . Proteomic studies have led to the identification of many pathogenicity and defense-related genes and proteins expressed during phytopathogen infections , resulting in the collection of an enormous amount of data . However , the molecular basis of plant-pathogen interactions remains an intensely active area of investigation . In this review , the role of differential analysis of proteins expressed during fungal , bacterial , and viral infection is discussed , as well as the role of JA and SA in the production of stress related proteins . Resistance acquired upon induction of stress related proteins in intact plant leaves is mediated by potentiation of pathogens via signal elicitors . Stress related genes extensively used in biotechnology had been cited . Stress related proteins identified must be followed through for studying the molecular mechanism for plant defense against pathogens .
WRKY proteins form a large family of plant transcription factors implicated in the modulation of numerous biological processes , such as growth , development and responses to various environmental stresses . However , the roles of the majority WRKY family members , especially in non-model plants , remain poorly understood . We identified CaWRKY40 from pepper . Transient expression in onion epidermal cells showed that CaWRKY40 can be targeted to nuclei and activates expression of a W-box-containing reporter gene . CaWRKY40 transcripts are induced in pepper by Ralstonia solanacearum and heat shock . To assess roles of CaWRKY40 in plant stress responses we performed gain- and loss-of-function experiments . Overexpression of CaWRKY40 enhanced resistance to R. solanacearum and tolerance to heat shock in tobacco . In contrast , silencing of CaWRKY40 enhanced susceptibility to R. solanacearum and impaired thermotolerance in pepper . Consistent with its role in multiple stress responses , we found CaWRKY40 transcripts to be induced by signalling mechanisms mediated by the stress hormones salicylic acid ( SA ) , jasmonic acid ( JA ) and ethylene ( ET ) . Overexpression of CaWRKY40 in tobacco modified the expression of hypersensitive response (HR)-associated and pathogenesis-related genes . Collectively , our results suggest that CaWRKY40 orthologs are regulated by SA , JA and ET signalling and coordinate responses to R. solanacearum attacks and heat stress in pepper and tobacco .
Allene oxide synthase ( AOS ) mediates the conversion of lipoxygenase-derived fatty acid hydroperoxides to unstable allene epoxides , which supply the precursors for the synthesis of the phytohormone jasmonic acid ( JA ) . In this study the characterization of AOS gene expression in flax ( Linum usitatissimum ) is reported . AOS was constitutively expressed in different organs of flax plants . Additionally , AOS gene expression was enhanced after mechanical wounding in both the directly damaged leaves and in the systemic tissue located distal to the treated leaves . This wound-induced accumulation of AOS required the de novo biosynthesis of other unknown proteins involved in the signaling pathway modulating wound-induced AOS gene expression . Furthermore , the wound-induced AOS mRNA accumulation was correlated with the increase in the levels of JA . Both JA and its precursor , 12-oxo-phytodienoic acid , activated AOS gene expression in a dose-dependent manner . Thus , JA could activate its own biosynthetic pathway in flax leaves . Moreover , neither salicylic acid ( SA ) nor aspirin influenced AOS enzymatic activity . It is interesting that pretreatment with SA or aspirin inhibited wound-induced accumulation of AOS transcripts . These results suggest that a potent inhibition of JA biosynthetic capacity in leaves can be affected by SA or aspirin at the level of AOS gene expression .
Harvestable , starch-storing organs of plants , such as fleshy taproots and tubers , are important agronomic products that are also suitable target organs for use in the molecular farming of recombinant proteins due to their strong sink strength . To exploit a promoter directing strong expression restricted to these storage organs , we isolated the promoter region ( 3.0   kb ) of SRD1 from sweetpotato ( Ipomoea batatas cv . ' White Star ' ) and characterized its activity in transgenic Arabidopsis , carrot , and potato using the β-glucuronidase ( GUS ) gene ( uidA ) as a reporter gene . The SRD1 promoter conferred root-specific expression in transgenic Arabidopsis , with SRD1 promoter activity increasing in response to exogenous IAA . A time-course study of the effect of IAA ( 50   μM ) revealed a maximum increase in SRD1 promoter activity at 24   h post-treatment initiation . A serial 5 ' deletion analysis of the SRD1 promoter identified regions related to IAA-inducible expression as well as regions containing positive and negative elements , respectively , controlling the expression level . In transgenic carrot , the SRD1 promoter mediated strong taproot-specific expression , as evidenced by GUS staining being strong in almost the entire taproot , including secondary phloem , secondary xylem and vascular cambium . The activity of the SRD1 promoter gradually increased with increasing diameter of the taproot in the transgenic carrot and was 10.71-fold higher than that of the CaMV35S promoter . The SRD1 promoter also directed strong tuber-specific expression in transgenic potato . Taken together , these results demonstrate that the SRD1 promoter directs strong expression restricted to the underground storage organs , such as fleshy taproots and tubers , as well as fibrous root tissues .
The effect of calcium on the secretion of α-amylase ( EC 3.2.1.1 ) and other hydrolases from aleurone layers of barley ( Hordeum vulgare L. cv . Himalaya ) was studied . Withdrawal of Ca(2 + ) from the incubation medium of aleurone layers preincubated in 5 μM gibberellic acid ( GA3 ) and 5 mM CaCl2 results in a 70 - 80 % reduction in the secretion of α-amylase activity to the incubation medium . Agar-gel electrophoresis shows that the reduction in α-amylase activity following Ca(2 + ) withdrawal is correlated with the disappearance of group B isoenzymes from the incubation medium . The secretion of isoenzymes of group A is unaffected by Ca(2 + ) . The addition of Ca(2 + ) stimulates the secretion of group-B isoenzymes but has no measurable effect on either the α-amylase activity or the isoenzyme pattern of aleurone-layer extracts . Pulse-labelling experiments with [(35)S]methionine show that Ca(2 + ) withdrawal results in a reduction in the secretion of labelled polypeptides into the incubation medium . Immunochemical studies also show that , in the absence of Ca(2 + ) , α-amylase isoenzymes of group B are not secreted into the incubation medium . In addition to its effect on α-amylase , Ca(2 + ) influences the secretion of other proteins including several acid hydrolases . The secretion of these other proteins shows the same dependence on Ca(2 + ) concentration as does that of α-amylase . Other cations can promote the secretion of α-amylase to less and varying extents . Strontium is 85 % as effective as Ca(2 + ) while Ba(2 + ) is only 10 % as effective . We conclude that Ca(2 + ) regulates the secretion of enzymes and other proteins from the aleurone layer of barley .
GIBBERELLIN INSENSITIVE DWARF1 ( GID1 ) encodes a soluble gibberellin ( GA ) receptor that shares sequence similarity with a hormone-sensitive lipase ( HSL ) . Previously , a yeast two-hybrid ( Y2H ) assay revealed that the GID1-GA complex directly interacts with SLENDER RICE1 ( SLR1 ) , a DELLA repressor protein in GA signaling . Here , we demonstrated , by pull-down and bimolecular fluorescence complementation ( BiFC ) experiments , that the GA-dependent GID1-SLR1 interaction also occurs in planta . GA(4 ) was found to have the highest affinity to GID1 in Y2H assays and is the most effective form of GA in planta . Domain analyses of SLR1 using Y2H , gel filtration , and BiFC methods revealed that the DELLA and TVHYNP domains of SLR1 are required for the GID1-SLR1 interaction . To identify the important regions of GID1 for GA and SLR1 interactions , we used many different mutant versions of GID1 , such as the spontaneous mutant GID1s , N- and C-terminal truncated GID1s , and mutagenized GID1 proteins with conserved amino acids replaced with Ala. The amino acid residues important for SLR1 interaction completely overlapped the residues required for GA binding that were scattered throughout the GID1 molecule . When we plotted these residues on the GID1 structure predicted by analogy with HSL tertiary structure , many residues were located at regions corresponding to the substrate binding pocket and lid . Furthermore , the GA-GID1 interaction was stabilized by SLR1 . Based on these observations , we proposed a molecular model for interaction between GA , GID1 , and SLR1 .
Fungal elicitor prepared from the cell walls of Aspergillum niger induces multiple responses of Hypericum perforatum cells , including nitric oxide ( NO ) generation , jasmonic acid ( JA ) biosynthesis , and hypericin production . To determine the role of NO and JA in elicitor-induced hypericin production , we study the effects of NO scavenger 2- to 4-carboxyphenyl-4,4 , 5,5-tetramethylimidazoline-1-oxyl-3-oxide ( cPITO ) , nitric oxide synthase inhibitor S , S'-1,3-phenylene-bis(1,2-ethanediyl)-bis-isothiourea , and inhibitors of the octadecanoid pathway on elicitor-induced NO generation , JA biosynthesis , and hypericin production . Pretreatment of the cells with cPITO and JA biosynthesis inhibitors suppresses not only the elicitor-induced NO generation and JA accumulation but also the elicitor-induced hypericin production , which suggests that both NO and JA are involved in elicitor-induced hypericin biosynthesis . S , S'-1,3-phenylene-bis(1,2-ethanediyl)-bis-isothiourea and cPITO inhibit both elicitor-induced NO generation and JA biosynthesis , while JA biosynthesis inhibitors do not affect the elicitor-induced NO generation , indicating that JA acts downstream of NO generation and that its biosynthesis is regulated by NO . External application of NO via its donor sodium nitroprusside induces hypericin production in the absence of fungal elicitor . Sodium-nitroprusside-induced hypericin production is blocked by JA biosynthesis inhibitors , showing that JA biosynthesis is essential for NO-induced hypericin production . The results demonstrate a causal relationship between elicitor-induced NO generation , JA biosynthesis , and hypericin production in H. perforatum cells and indicate a sequence of signaling events from NO to hypericin production , within which NO mediates the elicitor-induced hypericin biosynthesis at least partially via a JA-dependent signaling pathway .
cDNA clones encoding three additional serine carboxypeptidases ( Ser-CPs ) have been isolated from a gibberellic acid-induced barley aleurone cDNA library . The three deduced Ser-CPs belong to the two-chain subfamily of Ser-CPs ; they are synthesized as precursors with a putative signal peptide , propeptide , and linker peptide between the A and B chains . Their identification provides the proof for the existence of more than three Ser-CPs in cereal grains , and , based on their sequences , they may exhibit new substrate specificities . The expression of these and of the three previously isolated Ser-CPs from barley grains ( CP-MI , CP-MII , and CP-MIII ) has been investigated by Northern and Western analysis and RNA PCR . CP-MII is the only Ser-CP to be expressed and accumulate in the developing grain and is stored in its active form in the mature grain . All six Ser-CPs are expressed de novo in the germinating grain , in the scutellum , and/or in the aleurone . Furthermore , at least CP-MI , CP-MII , and CP-MIII are secreted into the endosperm . In addition , all Ser-CPs ( except CP-MI ) are also expressed in the roots and shoots of the growing seedling . This enzyme family thus appears to be ubiquitous in the barley plant , which suggests that Ser-CPs play additional roles besides their participation in the mobilization of storage proteins .
Jasmonates ( JAs ) are well-known regulators of stress , defence , and secondary metabolism in plants , with JA perception triggering extensive transcriptional reprogramming , including both activation and/or repression of entire metabolic pathways . We performed RNA sequencing based transcriptomic profiling of tobacco BY-2 cells before and after treatment with methyl jasmonate ( MeJA ) to identify novel transcriptional regulators associated with alkaloid formation . A total of 107,140 unigenes were obtained through de novo assembly , and at least 33,213 transcripts ( 31 % ) encode proteins , in which 3419 transcription factors ( TFs ) were identified , representing 72 gene families , as well as 840 transcriptional regulators ( TRs ) distributed among 19 gene families . After MeJA treatment BY-2 cells , 7260 differentially expressed transcripts were characterised , which include 4443 MeJA-upregulated and 2817 MeJA-downregulated genes . Of these , 227 TFs/TRs in 36 families were specifically upregulated , and 102 TFs/TRs in 38 families were downregulated in MeJA-treated BY-2 cells . We further showed that the expression of 12 ethylene response factors and four basic helix-loop-helix factors increased at the transcriptional level after MeJA treatment in BY-2 cells and displayed specific expression patterns in nic mutants with or without MeJA treatments . Our data provide a catalogue of transcripts of tobacco BY-2 cells and benefit future study of JA-modulated regulation of secondary metabolism in tobacco .
Phytoalexin synthesis is a defence-response- that is characterized by a requirement for a number of distinct elements , all of which must be present for the response to be expressed fully . These same elements : a signal , a cellular receptor , a signal transduction system and a responsive metabolic system , are also used to describe a stimulus-response system . A number of molecular species can function as signal molecules or elicitors of phytoalexin synthesis , including poly- and oligosaccharides , proteins and polypeptides , and fatty acids . Few receptors for elicitors have been identified but those that have been are proteins located on the plasma membrane of the plant . Induction of phytoalexin synthesis involves selective and co-ordinated activation of specific defence response genes , including those encoding the enzymes of phytoalexin synthesis , and these genes constitute the responsive metabolic system . The separate , and distant , locations of the receptor and the responsive genes means that the event in which the signal is perceived by the receptor must be relayed to the genes by means of a second messenger system . Several second messengers are candidates for such a coupling- or signal transduction-system , including udenosine-3',5'-cyclic monophosphate , Ca(2 + ) , diacylglycerol and inositol 1,4,5-trisphosphate , active oxygen species and jasmonic acid . Each has been examined as a possible component of the signal transduction system mediating between the elicitor receptor interaction and the phytoalexin synthesis it induces . Analysis of the signalling events is made complex by the simultaneous solicitation by the invading micro-organism of several defence responses , each of which might involve elements of a different signal system . The same complexity is evident which the role of phytoalexin accumulation in resistance is analysed . Evaluation of the contribution made by phytoalexin accumulation towards resistance has been attempted by the use of various inhibitors and enhancers of the process . Transgenic and mutant plants with specific alterations in one or more ot those elements necessary for the plant to respond to the signals for phytoalexin synthesis and other defence responses , are beginning to aid resolution of the complex pattern ot signalling events and the respective roles of the inducible defence mechanisms in resistance . CONTENTS Summary 1 I. Introduction 2 II . Chemistry of phytoalexins 3 III . Phytoalexin accumulation as a determinant of resistance 6 IV . Elicitation of phytoalexin accumulation 11 References 34 .