slotreck/pickle huggingface dataset:
In nature , herbivorous insects and plant pathogens are generally abundant when plants are flowering . Thus , plants face a diversity of attackers during their reproductive phase . Plant responses to one attacker can interfere with responses to a second attacker , and phytohormones that orchestrate plant reproduction are also involved in resistance to insect and pathogen attack . We quantified phytohormonal responses of flowering plants exposed to single or dual attack and studied resistance mechanisms of plants in the flowering stage . Flowering Brassica nigra were exposed to either a chewing caterpillar , a phloem-feeding aphid or a bacterial pathogen , and plant hormonal responses were compared with dual attack situations . We quantified phytohormones in inflorescences and leaves , and determined the consequences of hormonal changes for components of direct and indirect plant resistance . Caterpillars were the main inducers of jasmonates in inflorescences , and the phytohormonal profile of leaves was not affected by either insect or pathogen attack . Dual attack increased plant resistance to caterpillars , but compromised resistance to aphids . Parasitoid performance was negatively correlated with the performance of their hosts . We conclude that plants prioritize resistance of reproductive tissues over vegetative tissues , and that a chewing herbivore species is the main driver of responses in flowering B.   nigra .
During a compatible interaction , the sebacinoid root-associated fungi Piriformospora indica and Sebacina vermifera induce modification of root morphology and enhance shoot growth in Arabidopsis thaliana . The genomic traits common in these two fungi were investigated and compared with those of other root-associated fungi and saprotrophs . The transcriptional responses of the two sebacinoid fungi and of Arabidopsis roots to colonization at three different symbiotic stages were analyzed by custom-designed microarrays . We identified key genomic features characteristic of sebacinoid fungi , such as expansions for gene families involved in hydrolytic activities , carbohydrate-binding and protein-protein interaction . Additionally , we show that colonization of Arabidopsis correlates with the induction of salicylic acid catabolism and accumulation of jasmonate and glucosinolates ( GSLs ) . Genes involved in root developmental processes were specifically induced by S. vermifera at later stages during interaction . Using different Arabidopsis indole-GSLs mutants and measurement of secondary metabolites , we demonstrate the importance of the indolic glucosinolate pathway in the growth restriction of P. indica and S. vermifera and we identify indole-phytoalexins and specifically indole-carboxylic acids derivatives as potential key players in the maintenance of a mutualistic interaction with root endophytes .
We conducted a study of the patterns and dynamics of oxidized fatty acid derivatives ( oxylipins ) in potato leaves infected with the late-blight pathogen Phytophthora infestans . Two 18-carbon divinyl ether fatty acids , colneleic acid and colnelenic acid , accumulated during disease development . To date , there are no reports that such compounds have been detected in higher plants . The divinyl ether fatty acids accumulate more rapidly in potato cultivar Matilda ( a cultivar with increased resistance to late blight ) than in cultivar Bintje , a susceptible cultivar . Colnelenic acid reached levels of up to approximately 24 nmol ( 7 microgram ) per g fresh weight of tissue in infected leaves . By contrast , levels of members of the jasmonic acid family did not change significantly during pathogenesis . The divinyl ethers also accumulated during the incompatible interaction of tobacco with tobacco mosaic virus . Colneleic and colnelenic acids were found to be inhibitory to P. infestans , suggesting a function in plant defense for divinyl ethers , which are unstable compounds rarely encountered in biological systems .
Petal color , size , and morphology play important roles in protecting other floral organs , attracting pollinators , and facilitating sexual reproduction in plants . In a previous study , we obtained a petal degeneration mutant ( pdm ) from the ' FT ' doubled haploid line of Chinese cabbage and found that the candidate gene for pdm , Bra040093 , encodes the enzyme acyl-CoA oxidase1 . In this study , we sought to examine the gene networks regulating petal development in pdm plants . We show that the mRNA and protein expression of Bra040093 , which is involved in the jasmonic acid ( JA ) biosynthetic pathway , were significantly lower in the petals of pdm plants than in those of ' FT ' plants . Similarly , the JA and methyl jasmonate ( MeJA ) contents of petals were significantly lower in pdm plants than in ' FT ' plants and we found that exogenous application of these hormones to the inflorescences of pdm plants restored the ' FT ' phenotype . Comparative analyses of the transcriptomes of ' FT ' , pdm and pdm + JA ( pJA ) plants revealed 10,160 differentially expressed genes ( DEGs ) with consistent expression tendencies in ' FT ' vs. pdm and pJA vs. pdm comparisons . Among these DEGs , we identified 69 DEGs related to floral organ development , 11 of which are involved in petal development regulated by JA . On the basis of qRT-PCR verification , we propose regulatory pathways whereby JA may mediate petal development in the pdm mutant . We demonstrate that mutation of Bra040093 in pdm plants leads to reduced JA levels and that this in turn promotes changes in the expression of genes that are expressed in response to JA , ultimately resulting in petal degeneration . These findings thus indicate that JA is associated with petal development in Chinese cabbage . These results enhance our knowledge on the molecular mechanisms underlying petal development and lay the foundations for further elucidation of the mechanisms associated with floral organ development in Chinese cabbage .
BACKGROUND AND AIMS : Selected beneficial Pseudomonas spp . strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation . A crucial role for auxin in this long-term ( 1week ) , long-distance plant-microbe interaction has been demonstrated . METHODS : Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv . maculicola ( Psm ) and P. syringae pv . tomato DC3000 ( Pst ) , as well as Agrobacterium tumefaciens ( Atu ) and Escherichia coli ( Eco ) . Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain . Several Arabidopsis mutants with impaired responses to pathogens , impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed . KEY RESULTS : Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria ; root hair growth was stimulated and primary root growth was inhibited . Other plant- and soil-adapted bacteria induced similar root hair responses . The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2 . The single immune pathways dependent on salicylic acid , jasmonic acid and PAD4 are not directly involved in root hair growth stimulation ; however , in the mutual cross-talk with ethylene , they indirectly modify the extent of the stimulation of root hair growth . The Flg22 peptide does not initiate root hair stimulation as intact bacteria do , but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner . These early response phenomena are not associated with changes in auxin levels , as monitored with the pDR5::GUS auxin reporter . CONCLUSIONS : Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria . The root hair growth response is triggered in the range of hours after bacterial contact with roots and can be modulated by FLS2 signalling . Bacterial stimulation of root hair growth requires functional ethylene signalling and an efficient exocyst-dependent secretory machinery .
Tritrophic interactions involving a biocontrol agent , a pathogen , and a plant have been analyzed predominantly from the perspective of the biocontrol agent . To explore the adaptive strategies of wheat in response to beneficial , pathogenic , and combined microorganisms , we performed the first comprehensive transcriptomic , proteomic , and biochemical analysis in wheat roots after exposure to Bacillus velezensis CC09 , Gaeumannomyces graminis var . tritici , and their combined colonization , respectively . The transcriptional or translational programming of wheat roots inoculated with beneficial B. velezensis showed mild alterations compared with that of pathogenic G. graminis var . tritici . However , the combination of B. velezensis and G. graminis var . tritici activated a larger transcriptional or translational program than for each single microorganism , although the gene expression pattern was similar to that of individual infection by G. graminis var . tritici , suggesting a prioritization of defense against G. graminis var . tritici infection . Surprisingly , pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity made wheat pretreated with B. velezensis more sensitive to subsequent G. graminis var . tritici infection . Additionally , B. velezensis triggered a salicylic acid (SA)-dependent mode of induced systemic resistance that resembles pathogen-induced systemic acquired resistance . Wheat plants mainly depend on SA-mediated resistance , and not that mediated by jasmonic acid ( JA ) , against the necrotrophic pathogen G. graminis var . tritici . Moreover , SA-JA interactions resulted in antagonistic effects regardless of the type of microorganisms in wheat . Further enhancement of SA-dependent defense responses such as lignification to the combined infection was shown to reduce the level of induced JA-dependent defense against subsequent infection with G. graminis var . tritici . Altogether , our results demonstrate how the hexaploid monocot wheat responds to beneficial or pathogenic microorganisms and prolongs the onset of take-all disease through modulation of cell reprogramming and signaling events .
Seed dormancy and germination in higher plants are partially controlled by the plant hormones abscisic acid ( ABA ) and gibberellic acid ( GA ) . ABA establishes dormancy during embryo maturation , whereas GA breaks dormancy and induces germination . Previous attempts to identify GA response genes were confounded because GA mutants are not expected to germinate and , unlike GA auxotrophs , should fail to be rescued by exogenous GA . Here , we describe a screen for suppressors of the ABA-insensitive mutant ABI1 - 1 that enriches for GA auxotrophs and GA-insensitive mutants . The vast majority ( 76 % ) of the suppressors of ABI1 - 1 strongly resemble GA auxotrophs in that they are severely dwarfed and have dark green foliage and flowers with underdeveloped petals and stamen . Three isolates were alleles of the GA auxotroph ga1 . The remaining severe dwarves were not rescued by GA and belong to a single complementation group that we designate sly1 ( Sleepy 1 ) . The alleles of sly1 identified are the first recessive GA-insensitive mutations to reflect the full spectrum of GA-associated phenotypes , including the failure to germinate in the absence of the ABI1 - 1 lesion . Thus , we postulate that SLY1 is a key factor in GA reception .
The formation of amylase isozymes in germinating rice ( Oryza sativa ) seeds was studied by isoelectric focusing on polyacrylamide gel disc electrophoresis . Time sequence comparisons of the amylase zymogram were made between extracts from gibberellic acid-treated embryoless and embryo-attached half-endosperm of rice seeds . In both cases , 4 major and 9 to 10 minor isozyme bands were detectable at the maximal stage of the enzyme induction . However , in the embryo-attached half-seeds , bands started to diminish after the 5th day of incubation , in agreement with the results of time sequence analyses of enzyme activities . Nearly identical patterns of amylase isozyme bands on a polyacrylamide gel disc electrophoresis in combination with isoelectric focusing indicate the intrinsic role of gibberellic acid in the starch breakdown in germinating rice seeds . We tentatively assign the newly synthesized enzymes to be alpha-amylases based on experimental results concerning the lability of the preparation on a prolonged treatment at pH 3.3 and the stability on heat treatment for 15 minutes at 70 C.
Plants are continually exposed to pathogen attack but usually remain healthy because they can activate defences upon perception of microbes . However , pathogens have evolved to overcome plant immunity by delivering effectors into the plant cell to attenuate defence , resulting in disease . Recent studies suggest that some effectors may manipulate host transcription , but the specific mechanisms by which such effectors promote susceptibility remain unclear . We study the oomycete downy mildew pathogen of Arabidopsis , Hyaloperonospora arabidopsidis ( Hpa ) , and show here that the nuclear-localized effector HaRxL44 interacts with Mediator subunit 19a ( MED19a ) , resulting in the degradation of MED19a in a proteasome-dependent manner . The Mediator complex of ∼25 proteins is broadly conserved in eukaryotes and mediates the interaction between transcriptional regulators and RNA polymerase II . We found MED19a to be a positive regulator of immunity against Hpa . Expression profiling experiments reveal transcriptional changes resembling jasmonic acid/ethylene ( JA/ET ) signalling in the presence of HaRxL44 , and also 3 d after infection with Hpa . Elevated JA/ET signalling is associated with a decrease in salicylic acid (SA)-triggered immunity ( SATI ) in Arabidopsis plants expressing HaRxL44 and in med19a loss-of-function mutants , whereas SATI is elevated in plants overexpressing MED19a . Using a PR1::GUS reporter , we discovered that Hpa suppresses PR1 expression specifically in cells containing haustoria , into which RxLR effectors are delivered , but not in nonhaustoriated adjacent cells , which show high PR1::GUS expression levels . Thus , HaRxL44 interferes with Mediator function by degrading MED19 , shifting the balance of defence transcription from SA-responsive defence to JA/ET-signalling , and enhancing susceptibility to biotrophs by attenuating SA-dependent gene expression .
Plants are the primary producers in most terrestrial ecosystems and have complex defense systems to protect their produce . Defense-deficient , high-yielding agricultural monocultures attract abundant nonhuman consumers , but are alternatively defended through pesticide application and genetic engineering to produce insecticidal proteins such as Cry1Ac ( Bacillus thuringiensis ) . These approaches alter the balance between yield protection and maximization but have been poorly contextualized to known yield-defense trade-offs in wild plants . The native plant Nicotiana attenuata was used to compare yield benefits of plants transformed to be defenseless to those with a full suite of naturally evolved defenses , or additionally transformed to ectopically produce Cry1Ac . An insecticide treatment allowed us to examine yield under different herbivore loads in N.   attenuata 's native habitat . Cry1Ac , herbivore damage , and growth parameters were monitored throughout the season . Biomass and reproductive correlates were measured at season end . Non-Cry1Ac-targeted herbivores dominated on noninsecticide-treated plants , and increased the yield drag of Cry1Ac-producing plants in comparison with endogenously defended or undefended plants . Insecticide-sprayed Cry1Ac-producing plants lagged less in stalk height , shoot biomass , and flower production . In direct comparison with the endogenous defenses of a native plant , Cry1Ac production did not provide yield benefits for plants under observed herbivore loads in a field study .
Rice OsEDR1 is a sequence ortholog of Arabidopsis EDR1 . However , its molecular function is unknown . We show here that OsEDR1-suppressing/knockout ( KO ) plants , which developed spontaneous lesions on the leaves , have enhanced resistance to Xanthomonas oryzae pv . oryzae ( Xoo ) causing bacterial blight disease . This resistance was associated with increased accumulation of salicylic acid ( SA ) and jasmonic acid ( JA ) , induced expression of SA- and JA-related genes and suppressed accumulation of 1-aminocyclopropane-1-carboxylic acid ( ACC ) , the direct precursor of ethylene , and expression of ethylene-related genes . OsEDR1-KO plants also showed suppressed production of ethylene . Knockout of OsEDR1 suppressed the ACC synthase ( ACS ) gene family , which encodes the rate-limiting enzymes of ethylene biosynthesis by catalysing the formation of ACC . The lesion phenotype and enhanced bacterial resistance of the OsEDR1-KO plants was partly complemented by the treatment with ACC . ACC treatment was associated with decreased SA and JA biosynthesis in OsEDR1-KO plants . In contrast , aminoethoxyvinylglycine , the inhibitor of ethylene biosynthesis , promoted expression of SA and JA synthesis-related genes in OsEDR1-KO plants . These results suggest that ethylene is a negative signalling molecule in rice bacterial resistance . In the rice-Xoo interaction , OsEDR1 transcriptionally promotes the synthesis of ethylene that , in turn , suppresses SA- and JA-associated defence signalling .
Below-ground microbes can induce systemic resistance against foliar pests and pathogens on diverse plant hosts . The prevalence of induced systemic resistance ( ISR ) among plant-microbe-pest systems raises the question of host specificity in microbial induction of ISR . To test whether ISR is limited by plant host range ( , ) we tested the ISR-inducing ectomycorrhizal fungus Laccaria bicolor on the nonmycorrhizal plant Arabidopsis thaliana . We used the cabbage looper Trichoplusia ni and bacterial pathogen Pseudomonas syringae pv . tomato DC3000 ( Pto ) as readouts for ISR on Arabidopsis . We found that root inoculation with L.   bicolor triggered ISR against T.   ni and induced systemic susceptibility ( ISS ) against the bacterial pathogen Pto . We found that L.   bicolor-triggered ISR against T.   ni was dependent on jasmonic acid signaling and salicylic acid biosynthesis and signaling . Heat-killed L.   bicolor and chitin were sufficient to trigger ISR against T.   ni and ISS against Pto . The chitin receptor CERK1 was necessary for L.   bicolor-mediated effects on systemic immunity . Collectively our findings suggest that some ISR responses might not require intimate symbiotic association , but rather might be the result of root perception of conserved microbial signals .
Bensulfuron-methyl ( BSM ) is widely used in paddy soil for weed control . BSM residue in the soil has been known to inhibit the growth of sensitive crop plants . However , it is unknown whether BSM residue can affect the agrosystem in general . In this study , we have found significant effects of BSM on the infestation of Bemisia tabaci , Myzus persicae , and Tobacco mosaic virus ( TMV ) in Nicotiana tabacum . The soil was treated with BSM before the pest inoculation . The herbicide-treated tobaccos showed resistance to B. tabaci , but this resistance could not be detected until 15-day post-infestation when smaller number of adults B. tabaci appeared . In M. persicae assay , the longevity of all development stages of insects , and the fecundity of insects were not significantly affected when feeding on BSM-treated plants . In TMV assay , the BSM treatment also reduced virus-induced lesions in early infection time . However , the titer of TMV in BSM treated plants increased greatly over time and was over 40-fold higher than the mock-infected control plants after 20 days . Further studies showed that BSM treatment increased both jasmonic acid ( JA ) and salicylic acid ( SA ) levels in tobacco , as well as the expression of target genes in the JA and SA signaling pathways , such as NtWIPK , NtPR1a , and NtPAL . NtPR1a and NtPAL were initially suppressed after virus-inoculation , while NtRDR1 and NtRDR6 , which play a key role in fighting virus infection , only showed up- or were down-regulated 20 days post virus-inoculation . Taken together , our results suggested that BSM residue in the soil may affect the metabolism of important phytohormones such as JA and SA in sensitive plants and consequently affect the plant immune response against infections such as whitefly , aphids , and viruses .
Gibberellic acid ( GA3 ) , a plant growth regulator , is widely used in agriculture in many countries to accelerate the growth of fruits and vegetables . We designed histological , immunohistochemical , and biochemical studies to evaluate the deleterious effects of GA3 on the livers of adult pregnant rats and their offspring and to assess the possible ameliorative effect of Nigella sativa Linn . ( NsL.oil ) against these effects . Twenty-four pregnant albino rats were utilized , randomly divided into four groups : The first group was used as a negative control group , while the second group ( positive control group ) was provided NsL.oil at a dose of 100   mg/kg of bodyweight . Animals in the third group ( GA3 group ) were provided 200   ppm of GA3 dissolved in distilled water from the 7th day of pregnancy until 1   day after delivery . Animals in the last group ( GA3   +   NsL.oil group ) were provided GA3 and NsL-oil at the same doses as mentioned above . One day after delivery , each group of lactating mothers and their pups were sacrificed . Liver specimens were subjected to histopathological , immunohistochemical , and biochemical examinations . The livers of rats from the GA3 group showed various degenerative changes , being predominant in the livers of the mothers compared with the offspring . The pathological changes in the livers of the offspring suggested transplacental passage of GA3 . The results reveal that GA3 ingestion induced a significant increase in alanine aminotransferase ( ALT ) and aspartate transaminase ( AST ) activities in the serum of both groups of mothers and their pups , with a significant increment in lipid peroxidation as evidenced by enhanced malondialdehyde ( MDA ) levels with significant decrements in superoxide dismutase ( SOD ) , catalase ( CAT ) , and glutathione peroxidase ( GPx ) enzymatic activities in comparison with control groups in the liver of mothers and their offspring . Histopathological examination showed hydropic degeneration and inflammatory cellular infiltration . Additionally , there was fibrosis around the portal area . Moreover , immunolocalization revealed downregulation of the expression of the antiapoptotic marker Bcl-2 in hepatocytes and upregulation of the expression of the apoptotic marker Bax in the treated group . Concomitant use of NsL.oil along with GA3 exerted a considerable reversing effect on histopathological and biochemical changes in the livers of mother groups and their pups . The results of the present study highlight the consequences of exposure to GA3 during pregnancy on hepatic tissue in both mothers and their offspring . Furthermore , the study suggests use of NsL.oil as a potential protective strategy against GA3-induced liver toxicity .