depudecin: a novel compound inducing the flat phenotype of nih3t3 cells doubly transformed by ras- and src-oncogene, produced by alternaria brassicicola.a novel compound depudecin inducing the flat phenotype of ras- and src- transformed nih3t3 cells at a concentration of 1 microgram/ml was isolated from the culture broth of alternaria brassicicola. based on its spectroscopic characteristics and x-ray crystallographic analysis of its bis-(1s)-(-)-camphanate, the structure of depudecin was determined to be (2r,3s,4s,5e,7s,8s,9r)-2,9- dihydroxy-3,4;7,8-diepoxy-undeca-5,10-diene.19921500354
further electron microscope studies of the conidium of alternaria brassicicola. 19695393546
notes on an albino mutant of alternaria brassicicola. 19685750838
an electron microscope study of spore structure and development in alternaria brassicicola. 19685751436
an antibiotic complex from alternaria brassicicola. 19695801795
antibiotic production and biocontrol activity by bacillus subtilis cl27 and bacillus pumilus cl45.bacillus subtilis cl27 and b. pumilus cl45 showed similar activity against botrytis cinerea in in vitro plate assays. in a seedling bioassay, however, b. subtilis cl27 had activity similar to a commercial fungicide while b. pumilus cl45 failed completely to prevent seedling damping-off caused by bot. cinerea. antibiotic production by the two bacillus strains was found to depend on the growth substrate and highest antibiotic production was found on media based on homogenized cabbage tissue. antib ...19957698955
interactions between the glycoalkaloids solasonine and solamargine in relation to inhibition of fungal growth.inhibition of mycelium development in phoma medicaginis and rhizoctonia solani by solamargine and solasonine generally increased with increasing ph. p. medicaginis was the more susceptible species and solamargine the more potent compound. solasonine was inactive against r. solani over the tested ph range (5-8). dose-response curves confirmed these differential effects. solamargine caused 50% growth inhibition in p. medicaginis at 60 microm (at ph 7) whereas no other treatment achieved this effec ...19947765652
pathogen-induced systemic activation of a plant defensin gene in arabidopsis follows a salicylic acid-independent pathway.a 5-kd plant defensin was purified from arabidopsis leaves challenged with the fungus alternaria brassicicola and shown to possess antifungal properties in vitro. the corresponding plant defensin gene was induced after treatment of leaves with methyl jasmonate or ethylene but not with salicylic acid or 2,6-dichloroisonicotinic acid. when challenged with a. brassicicola, the levels of the plant defensin protein and mrna rose both in inoculated leaves and in nontreated leaves of inoculated plants ...19968989885
evidence that the role of plant defensins in radish defense responses is independent of salicylic acid.radish leaves contain two homologous 5-kda plant defensins which accumulate systemically upon infection by fungal pathogens (f.r.g. terras et al., 1995, plant cell 7: 573-588). here we report on the molecular cloning of the cdnas encoding the two pathogen-inducible plant defensin isoforms from radish (raphanus sativus l.) leaves. tissue-print and whole-leaf electroblot immunostaining showed that the plant defensin peptides not only accumulate at high levels at or immediately around the infection ...19989715534
concomitant activation of jasmonate and ethylene response pathways is required for induction of a plant defensin gene in arabidopsis.activation of the plant defensin gene pdf1.2 in arabidopsis by pathogens has been shown previously to be blocked in the ethylene response mutant ein2-1 and the jasmonate response mutant coi1-1. in this work, we have further investigated the interactions between the ethylene and jasmonate signal pathways for the induction of this defense response. inoculation of wild-type arabidopsis plants with the fungus alternaria brassicicola led to a marked increase in production of jasmonic acid, and this r ...19989836748
separate jasmonate-dependent and salicylate-dependent defense-response pathways in arabidopsis are essential for resistance to distinct microbial pathogens.the endogenous plant hormones salicylic acid (sa) and jasmonic acid (ja), whose levels increase on pathogen infection, activate separate sets of genes encoding antimicrobial proteins in arabidopsis thaliana. the pathogen-inducible genes pr-1, pr-2, and pr-5 require sa signaling for activation, whereas the plant defensin gene pdf1.2, along with a pr-3 and pr-4 gene, are induced by pathogens via an sa-independent and ja-dependent pathway. an arabidopsis mutant, coi1, that is affected in the ja-res ...19989844023
the promoter of the plant defensin gene pdf1.2 from arabidopsis is systemically activated by fungal pathogens and responds to methyl jasmonate but not to salicylic acid.the plant defensin pdf1.2 has previously been shown to accumulate systemically via a salicylic acid-independent pathway in leaves of arabidopsis upon challenge by fungal pathogens. to further investigate the signalling and transcriptional processes underlying plant defensin induction, a dna fragment containing 1184 bp and 1232 bp upstream of the transcriptional and translational start sites, respectively, was cloned by inverse pcr. to test for promoter activity this dna fragment was linked to th ...19989869413
deficiency in phytoalexin production causes enhanced susceptibility of arabidopsis thaliana to the fungus alternaria brassicicola.the phytoalexin-deficient arabidopsis mutant pad3-1, which is affected in the production of the indole-type phytoalexin camalexin, has previously been shown not to display altered susceptibility to either the bacterium pseudomonas syringae (glazebrook & ausubel 1994; proc. natl. acad. sci. usa, 91: 8955-8959) or the biotrophic fungi peronospora parasitica (glazebrook et al. 1997; genetics, 146: 381-392) and erysiphe orontii (reuber et al. 1998; plant j. 16: 473-485). we now show that this mutant ...199910476063
occurrence of a lipase in spores of alternaria brassicicola with a crucial role in the infection of cauliflower leaves.alternaria brassicicola is a pathogen that penetrates directly through the host cuticle thanks to several serine esterases, according to our findings. among these, an 80-kda lipase (e.c 3.1.1. 3) was detected by sds-page and immunoblotting in the water washings of ungerminated spores. the purified lipase cross-reacted with botrytis cinerea anti-lipase antibodies, which were reported to inhibit the in vitro lipase activity. anti-lipase antibodies were added to a conidial suspension of a. brassici ...199910556710
arabidopsis pad3, a gene required for camalexin biosynthesis, encodes a putative cytochrome p450 monooxygenase.phytoalexins are low molecular weight antimicrobial compounds that are synthesized in response to pathogen attack. the phytoalexin camalexin, an indole derivative, is produced by arabidopsis in response to infection with the bacterial pathogen pseudomonas syringae. the phytoalexin deficient 3 (pad3) mutation, which causes a defect in camalexin production, has no effect on resistance to p. syringae but compromises resistance to the fungal pathogen alternaria brassicicola. we have now isolated pad ...199910590168
requirement of functional ethylene-insensitive 2 gene for efficient resistance of arabidopsis to infection by botrytis cinerea.inoculation of wild-type arabidopsis plants with the fungus alternaria brassicicola results in systemic induction of genes encoding a plant defensin (pdf1.2), a basic chitinase (pr-3), and an acidic hevein-like protein (pr-4). pathogen-induced induction of these three genes is almost completely abolished in the ethylene-insensitive arabidopsis mutant ein2-1. this indicates that a functional ethylene signal transduction component (ein2) is required in this response. the ein2-1 mutants were found ...199910594097
coordinated plant defense responses in arabidopsis revealed by microarray analysis.disease resistance is associated with a plant defense response that involves an integrated set of signal transduction pathways. changes in the expression patterns of 2,375 selected genes were examined simultaneously by cdna microarray analysis in arabidopsis thaliana after inoculation with an incompatible fungal pathogen alternaria brassicicola or treatment with the defense-related signaling molecules salicylic acid (sa), methyl jasmonate (mj), or ethylene. substantial changes (up- and down-regu ...200011027363
fistupyrone, a novel inhibitor of the infection of chinese cabbage by alternaria brassicicola, from streptomyces sp. tp-a0569.a new microbial metabolite, designated fistupyrone, was isolated from the culture broth of a plant-associated streptomyces sp. tp-a0569. fistupyrone inhibited the in vivo infection of the seedlings of chinese cabbage by alternaria brassicicola tp-f0423, the cause of alternaria leaf spot, without any in vitro fungicidal activity.200011132956
antifungal activity of venenatine, an indole alkaloid isolated from alstonia venenata.the indole alkaloid venenatine exhibited antifungal activity against some plant pathogenic and saprophytic fungi. venenatine in an aqueous acetic acid solution inhibited spore germination of all the 10 tested fungi, fusarium udum, alternaria brassicicola, ustilago cynodontis and aspergillus flavus showed an especially high sensitivity towards this compound, exhibiting germination levels below 10%. the spore germination and colony development of the parasitic fungus erysiphe pisi, which causes po ...200011271828
study of the role of antimicrobial glucosinolate-derived isothiocyanates in resistance of arabidopsis to microbial pathogens.crude aqueous extracts from arabidopsis leaves were subjected to chromatographic separations, after which the different fractions were monitored for antimicrobial activity using the fungus neurospora crassa as a test organism. two major fractions were obtained that appeared to have the same abundance in leaves from untreated plants versus leaves from plants challenge inoculated with the fungus alternaria brassicicola. one of both major antimicrobial fractions was purified to homogeneity and iden ...200111299350
combination of trichoderma harzianum endochitinase and a membrane-affecting fungicide on control of alternaria leaf spot in transgenic broccoli plants.progeny from transgenic broccoli (cv. green comet) expressing a trichoderma harzianum endochitinase gene were used to assess the interaction between endochitinase and the fungicide bayleton in the control of alternaria brassicicola. in vitro assays have shown synergistic effects of endochitinase and fungicides on fungal pathogens. our study examined the in planta effects of endochitinase and bayleton, individually and in combination. two month old transgenic and non-transgenic plants were spraye ...200111341311
synthesis and in vitro antifungal activity of 1-amino-3,4-dialkylnaphthalene-2-carbonitriles and their analogues.twenty-four 3- and/or 4-alkyl-substituted 1-aminonaphthalene-2-carbonitriles and their analogues were prepared and evaluated for growth-inhibiting activity against four phytopathogenic fungi: fusarium culmorum, alternaria brassicicola, botrytis cinerea and penicillium expansum. the results obtained were compared with the activity of a commercial fungicide. the highest fungistatic activity was revealed by amino nitriles having hydrogen atoms or only one short alkyl group (ch3, c2h5) at the 3- or ...200111464795
plant defense in the absence of jasmonic acid: the role of cyclopentenones.the arabidopsis opr3 mutant is defective in the isoform of 12-oxo-phytodienoate (opda) reductase required for jasmonic acid (ja) biosynthesis. oxylipin signatures of wounded opr3 leaves revealed the absence of detectable 3r,7s-ja as well as altered levels of its cyclopentenone precursors opda and dinor opda. in contrast to ja-insensitive coi1 plants and to the fad3 fad7 fad8 mutant lacking the fatty acid precursors of ja synthesis, opr3 plants exhibited strong resistance to the dipteran bradysia ...200111592974
differential effectiveness of salicylate-dependent and jasmonate/ethylene-dependent induced resistance in arabidopsis.salicylic acid (sa), jasmonic acid (ja), and ethylene (et) are each involved in the regulation of basal resistance against different pathogens. these three signals play important roles in induced resistance as well. sa is a key regulator of pathogen-induced systemic acquired resistance (sar), whereas ja and et are required for rhizobacteria-mediated induced systemic resistance (isr). both types of induced resistance are effective against a broad spectrum of pathogens. in this study, we compared ...200211858171
esa1, an arabidopsis mutant with enhanced susceptibility to a range of necrotrophic fungal pathogens, shows a distorted induction of defense responses by reactive oxygen generating arabidopsis thaliana mutant, esa1, that shows enhanced susceptibility to the necrotrophic pathogens alternaria brassicicola, botrytis cinerea and plectosphaerella cucumerina, but has wild-type levels of resistance to the biotrophic pathogens pseudomonas syringae pv. tomato and peronospora parasitica. the enhanced susceptibility towards necrotrophic pathogens correlated with a delayed induction of phytoalexin accumulation and delayed induction of the plant defensin gene pdf1.2 upon inoculation ...200211862946
synthesis of new pyrroles and their biological activities.coumarino acid hydrazides and acid hydrazide of 2-oxy 3, 5, 6-trichloropyridine were prepared in two steps. these acid hydrazides on condensation with acetonyl acetone i.e. 2,5-hexanedione yields new pyrroles. these pyrroles showed good to moderate antimicrobial activities against alternaria brassicicola, aspergillus niger, e. coli and lactobacillus.199912024978
effect of berberine and (+/-)-bicuculline isolated from corydalis chaerophylla on spore germination of some fungi.berberine and (+/-)-bicuculline were isolated from roots and leaves, respectively, of corydalis chaerophylla. both were effective in vitro against spore germination of some plant pathogenic fungi (alternaria brassicicola, a. brassicae, a. cheiranthi, a. melongenae, a. solani, colletotrichum musae, c. falcatum, curvularia penniseti, c. lunata, c. maculans, c. pallescens, curvularia sp., erysiphe pisi, e. cichoracearum, erysiphe sp., fusarium udum, helminthosporium spiciferum, h. penniseti, h. fru ...200212058395
characterization of inhibitor-resistant histone deacetylase activity in plant-pathogenic fungi.hc-toxin, a cyclic peptide made by the filamentous fungus cochliobolus carbonum, is an inhibitor of histone deacetylase (hdac) from many organisms. it was shown earlier that the hdac activity in crude extracts of c. carbonum is relatively insensitive to hc-toxin as well as to the chemically unrelated hdac inhibitors trichostatin and d85, whereas the hdac activity of aspergillus nidulans is sensitive (g. brosch et al., biochemistry 40:12855-12863, 2001). here we report that hc-toxin-resistant hda ...200212456002
arabidopsis ecotype variability in camalexin production and reaction to infection by alternaria brassicicola.camalexin production was compared in 24 ecotypes of arabidopsis thaliana. detached arabidopsis leaves were inoculated with cochliobolus carbonum, an incompatible pathogen of arabidopsis, to test the ability of each ecotype to produce camalexin. whole plants were inoculated with alternaria brassicicola, a crucifer pathogen, to determine if there was a correlation between the ability of an ecotype to produce camalexin and its resistance to a. brassicicola. all ecotypes were capable of producing ca ...200212523558
cloning of a gene encoding an alt a 1 isoallergen differentially expressed by the necrotrophic fungus alternaria brassicicola during arabidopsis infection.alternaria species are considered some of the most important fungi responsible for allergenic morbidity in humans. the alternaria protein that elicits the most intense allergic reaction in humans is alt a 1, yet no biological function has been identified for this protein. in this study, suppression subtractive hybridization and virtual northern blots were used to identify and characterize an alt a 1 homolog in the phytopathogenic fungus alternaria brassicicola. rna was extracted from a. brassici ...200312676721
the cdna microarray analysis using an arabidopsis pad3 mutant reveals the expression profiles and classification of genes induced by alternaria brassicicola attack.the hypersensitive response (hr) was induced in a wild-type arabidopsis thaliana plant (columbia) (col-wt) by inoculation with alternaria brassicicola that causes the development of small brown necrotic lesions on the leaves. by contrast, pad3-1 mutants challenged with a. brassicicola produced spreading lesions. the cell death in pad3-1 mutants could not inhibit the pathogen growth and development, although both production of h(2)o(2) and localized cell death were similar in col-wt and pad3-1 pl ...200312721378
characterization of the early response of arabidopsis to alternaria brassicicola infection using expression profiling.all tested accessions of arabidopsis are resistant to the fungal pathogen alternaria brassicicola. resistance is compromised by pad3 or coi1 mutations, suggesting that it requires the arabidopsis phytoalexin camalexin and jasmonic acid (ja)-dependent signaling, respectively. this contrasts with most well-studied arabidopsis pathogens, which are controlled by salicylic acid-dependent responses and do not benefit from absence of camalexin or ja. here, mutants with defects in camalexin synthesis (p ...200312805591
systemic gene expression in arabidopsis during an incompatible interaction with alternaria brassicicola.pathogen challenge can trigger an integrated set of signal transduction pathways, which ultimately leads to a state of "high alert," otherwise known as systemic or induced resistance in tissue remote to the initial infection. although large-scale gene expression during systemic acquired resistance, which is induced by salicylic acid or necrotizing pathogens has been previously reported using a bacterial pathogen, the nature of systemic defense responses triggered by an incompatible necrotrophic ...200312805628
the botrytis susceptible1 gene encodes an r2r3myb transcription factor protein that is required for biotic and abiotic stress responses in arabidopsis.the molecular and cellular mechanisms involved in plant resistance to the necrotrophic fungal pathogen botrytis cinerea and their genetic control are poorly understood. botrytis causes severe disease in a wide range of plant species, both in the field and in postharvest situations, resulting in significant economic losses. we have isolated the bos1 (botrytis-susceptible1) gene of arabidopsis based on a t-dna insertion allele that resulted in increased susceptibility to botrytis infection. the bo ...200314555693
expression profiles of arabidopsis phospholipase a iia gene in response to biotic and abiotic stresses.we examined the transcripts that showed changes among the ca.7,000 arabidopsis full-length cdnas under biotic and abiotic stresses. expression of arabidopsis phospholipase a iia (atpla iia) gene was induced by various treatments such as pathogen inoculation (alternaria alternata, alternaria brassicicola and colletotrichum higginsianum), cold, high-salinity, abscisic acid, salicylic acid, methyl jasmonate, ethephon, paraquat, rose bengal, uv-c and cuso(4)-treatments. the regulation of atpla iia g ...200314634163
identification of alternaria brassicicola genes expressed in planta during pathogenesis of arabidopsis thaliana.alternaria brassicicola is a necrotrophic fungal pathogen that causes black spot disease on cruciferous plants including economically important brassica species. the purpose of this study was to identify fungal genes expressed during infection of arabidopsis. in order to identify candidate genes involved in pathogenicity, we employed suppression subtractive hybridization (ssh) between rna isolated from a. brassicicola spores incubated in water and on the leaf surface of the arabidopsis ecotype l ...200414732258
beta-amino-butyric acid-induced resistance against necrotrophic pathogens is based on aba-dependent priming for callose.the non-protein amino acid beta-amino-butyric acid (baba) protects plants against a wide range of pathogens. we have examined the effectiveness and mode of action of baba on resistance against two necrotrophic pathogens. treatment of arabidopsis with baba induced resistance against alternaria brassicicola and plectosphaerella cucumerina to a similar level by jasmonic acid (ja). conversely, treatment with benzothiadiazole (bth), a functional analogue of salicylic acid (sa), had no significant eff ...200415053765
real-time pcr monitoring of fungal development in arabidopsis thaliana infected by alternaria brassicicola and botrytis cinerea.reliable methods for disease severity assessment are of crucial importance in the study of plant pathogen interactions, either for disease diagnostic on the field or to assess phenotypical differences in plants or pathogen strains. currently, most of the assays used in fungal disease diagnostic rely on visual assessment of the symptoms, lesion diameter measurement or spore counting. however, these tests are tedious and often cannot discriminate between slightly different levels of resistance. be ...200415191738
the bos loci of arabidopsis are required for resistance to botrytis cinerea infection.three botrytis-susceptible mutants bos2, bos3, and bos4 which define independent and novel genetic loci required for arabidopsis resistance to botrytis cinerea were isolated. the bos2 mutant is susceptible to b. cinerea but retains wild-type levels of resistance to other pathogens tested, indicative of a defect in a response pathway more specific to b. cinerea. the bos3 and bos4 mutants also show increased susceptibility to alternaria brassicicola, another necrotrophic pathogen, suggesting a bro ...200415500471
chlorophyllase 1, a damage control enzyme, affects the balance between defense pathways in plants.accumulation of reactive oxygen species (ros) is central to plant response to several pathogens. one of the sources of ros is the chloroplast because of the photoactive nature of the chlorophylls. chlorophyllase 1 (encoded by atclh1) of arabidopsis thaliana is quickly induced after tissue damage (e.g., caused by the bacterial necrotroph erwinia carotovora or the necrotrophic fungus alternaria brassicicola). rna interference silencing of atclh1 resulted in failure to degrade free chlorophyll afte ...200415598807
crosstalk in the responses to abiotic and biotic stresses in arabidopsis: analysis of gene expression in cytochrome p450 gene superfamily by cdna microarray.from arabidopsis full-length cdna libraries, we collected ca. 7000 (7k) independent full-length cdnas to prepare a cdna microarray. the 7k cdna collection contains 49 cytochrome p450 genes. in this study, expression patterns of these cytochrome p450 genes were analyzed by a full-length cdna microarray under various treatments, such as hormones (salicylic acid, jasmonic acid, ethylene, abscisic acid), pathogen-inoculation ( alternaria brassicicola , alternaria alternata ), paraquat, rose bengal, ...200415604685
histone deacetylase19 is involved in jasmonic acid and ethylene signaling of pathogen response in arabidopsis.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 revea ...200515749761
characterization of mutations in the two-component histidine kinase gene abnik1 from alternaria brassicicola that confer high dicarboximide and phenylpyrrole resistance.highly iprodione- and fludioxonil-resistant field and laboratory isolates of a. brassicicola were found to be either moderately sensitive or tolerant to osmotic stress. abnik1, a two-component histidine kinase gene, was isolated from a fungicide-sensitive strain. the predicted protein possessed the six tandem amino acid repeats at the n-terminal end, which is a landmark of osmosensor histidine kinases from filamentous fungi. a comparison of the nucleic acid sequences of the abnik1 gene from fung ...200515765227
genetic structure of populations of alternaria brassicicola suggests the occurrence of sexual recombination.substantial polymorphism was detected between isolates from five populations of alternaria brassicicola attacking cakile maritima along the new south wales coast of australia, with a maximum of two genotypes being shared between population pairs. of ten pair-wise population comparisons, six had no pathogen genotypes in common; only one genotype occurred five times, and most (93 %) were found only once. although an upgma based on nei's measure of genetic distance separated the five populations, a ...200515839106
differences in cell death induction by phytophthora elicitins are determined by signal components downstream of map kinase kinase in different species of nicotiana and cultivars of brassica rapa and raphanus sativus.elicitins are small, secreted proteins produced by species of the plant-pathogenic oomycete phytophthora. they induce hypersensitive cell death in most nicotiana species and in some cultivars of brassica rapa and raphanus sativus. in this study, two true-breeding fast cycling b. rapa lines were established that showed severe necrosis (line 7-r) or no visible response (line 18-nr) after treatment with elicitin. unexpectedly, microscopic examination revealed localized cell death in line 18-nr plan ...200515980203
a colletotrichum gloeosporioides-induced esterase gene of nonclimacteric pepper (capsicum annuum) fruit during ripening plays a role in resistance against fungal infection.ripe fruits of pepper (capsicum annuum) are resistant to the anthracnose fungus, colletotrichum gloeosporioides, whereas unripe-mature fruits are susceptible. a pepper esterase gene (pepest) that is highly expressed during an incompatible interaction between the ripe fruit of pepper and c. gloeosporioides was previously cloned. deduced amino acid sequence of pepest cdna showed homology to both esterases and lipases, and contained -hgggf- and -gxsxg- motifs and a catalytic triad. inhibition of pe ...200516021337
secretome analysis reveals an arabidopsis lipase involved in defense against alternaria brassicicola.the arabidopsis thaliana secretome was analyzed by the proteomic approach, which led to the identification of secreted proteins implicated in many aspects of cell biology. we then investigated the change in the arabidopsis secretome in response to salicylic acid and identified several proteins involved in pathogen response. one of these, a secreted lipase with a gdsl-like motif designated gdsl lipase1 (glip1), was further characterized for its function in disease resistance. glip1 plants were ma ...200516126835
signal signature and transcriptome changes of arabidopsis during pathogen and insect attack.plant defenses against pathogens and insects are regulated differentially by cross-communicating signaling pathways in which salicylic acid (sa), jasmonic acid (ja), and ethylene (et) play key roles. to understand how plants integrate pathogen- and insect-induced signals into specific defense responses, we monitored the dynamics of sa, ja, and et signaling in arabidopsis after attack by a set of microbial pathogens and herbivorous insects with different modes of attack. arabidopsis plants were e ...200516167763
repressor- and activator-type ethylene response factors functioning in jasmonate signaling and disease resistance identified via a genome-wide screen of arabidopsis transcription factor gene identify transcription factors (tfs) involved in jasmonate (ja) signaling and plant defense, we screened 1,534 arabidopsis (arabidopsis thaliana) tfs by real-time quantitative reverse transcription-pcr for their altered transcript at 6 h following either methyl ja treatment or inoculation with the incompatible pathogen alternaria brassicicola. we identified 134 tfs that showed a significant change in expression, including many apetala2/ethylene response factor (ap2/erf), myb, wrky, and nac tf ...200516183832
heterotrimeric g proteins facilitate arabidopsis resistance to necrotrophic pathogens and are involved in jasmonate signaling.heterotrimeric g proteins have been previously linked to plant defense; however a role for the gbetagamma dimer in defense signaling has not been described to date. using available arabidopsis (arabidopsis thaliana) mutants lacking functional galpha or gbeta subunits, we show that defense against the necrotrophic pathogens alternaria brassicicola and fusarium oxysporum is impaired in gbeta-deficient mutants while galpha-deficient mutants show slightly increased resistance compared to wild-type c ...200616339801
a high throughput targeted gene disruption method for alternaria brassicicola functional genomics using linear minimal element (lme) constructs.alternaria brassicicola causes black spot disease of cultivated brassicas and has been used consistently as a necrotrophic fungal pathogen for studies with arabidopsis. in a. brassicicola, mutant generation has been the most rate-limiting step for the functional analysis of individual genes due to low efficiency of both transformation and targeted integration. to improve the targeted gene disruption efficiency as well as to expedite gene disruption construct production, we used a short linear co ...200616404948
wrky70 modulates the selection of signaling pathways in plant defense.cross-talk between signal transduction pathways is a central feature of the tightly regulated plant defense signaling network. the potential synergism or antagonism between defense pathways is determined by recognition of the type of pathogen or pathogen-derived elicitor. our studies have identified wrky70 as a node of convergence for integrating salicylic acid (sa)- and jasmonic acid (ja)-mediated signaling events during plant response to bacterial pathogens. here, we challenged transgenic plan ...200616623907
molecular cloning of abgst1 encoding a glutathione transferase differentially expressed during exposure of alternaria brassicicola to isothiocyanates.the abgst1 gene encoding a glutathione transferase from the necrotrophic pathogen alternaria brassicicola was cloned from a benzyl isothiocyanate-treated conidial culture using differential display reverse transcription. the deduced amino-acid sequence of abgst1p showed a significant degree of similarity to glutathione transferase-i from saccharomyces cerevisiae and glutathione transferase-iii from schizosaccharomyces pombe. the transcription of abgst1 was significantly enhanced by isothiocyanat ...200616640580
altering glucosinolate profiles modulates disease resistance in plants.plant diseases are major contributing factors for crop loss in agriculture. here, we show that arabidopsis plants with high levels of novel glucosinolates (gss) as a result of the introduction of single cyp79 genes exhibit altered disease resistance. arabidopsis expressing cyp79d2 from cassava accumulated aliphatic isopropyl and methylpropyl gs, and showed enhanced resistance against the bacterial soft-rot pathogen erwinia carotovora, whereas arabidopsis expressing the sorghum cyp79a1 or over-ex ...200616709192
arabidopsis map kinase 4 regulates salicylic acid- and jasmonic acid/ethylene-dependent responses via eds1 and pad4.arabidopsis mpk4 has been implicated in plant defense regulation because mpk4 knockout plants exhibit constitutive activation of salicylic acid (sa)-dependent defenses, but fail to induce jasmonic acid (ja) defense marker genes in response to ja. we show here that mpk4 mutants are also defective in defense gene induction in response to ethylene (et), and that they are more susceptible than wild-type (wt) to alternaria brassicicola that induces the et/ja defense pathway(s). both sa-repressing and ...200616813576
herbivore-induced resistance against microbial pathogens in arabidopsis.caterpillars of the herbivore pieris rapae stimulate the production of jasmonic acid (ja) and ethylene (et) in arabidopsis (arabidopsis thaliana) and trigger a defense response that affects insect performance on systemic tissues. to investigate the spectrum of effectiveness of p. rapae-induced resistance, we examined the level of resistance against different pathogens. although the necrotrophic fungus alternaria brassicicola is sensitive to ja-dependent defenses, herbivore-induced resistance was ...200616829584
bioefficacy of iprodione against two desapers, its compatibility with t. harzianum and residues on cabbage crop.iprodione (3-(3,5-dichlorophenyl)-n-isopropyl-2,4-dioxoimidazolidine-1-carboxamide) bio-assayed against fungi alternaria brassicicola and sclerotinia sclerotiorum was found to be highly effective for inhibiting these desapers. inhibition of a. brassicicola was 100% up to the dose of 75 ppm and for s. sclerotiorum there was 50% inhibition for the same concentration. formulation of the pesticide was applied @ 500 and 1000 g. a.i./ha on the cabbage crop grown in the fields. residues in the edible s ...200616893782
metabolic changes in arabidopsis thaliana expressing the feedback-resistant anthranilate synthase alpha subunit gene oasa1d.anthranilate synthase (as) is a key enzyme in tryptophan (trp) biosynthesis. metabolic changes in transgenic arabidopsis plants expressing the feedback-resistant anthranilate synthase alpha subunit gene oasa1d were investigated with respect to trp synthesis and effects on secondary metabolism. the trp content varied depending on the transgenic line, with some lines showing an approximately 200-fold increase. the levels of as activity in crude extracts from the transgenic lines were comparable to ...200616989878
nps6, encoding a nonribosomal peptide synthetase involved in siderophore-mediated iron metabolism, is a conserved virulence determinant of plant pathogenic ascomycetes.nps6, encoding a nonribosomal peptide synthetase, is a virulence determinant in the maize (zea mays) pathogen cochliobolus heterostrophus and is involved in tolerance to h(2)o(2). deletion of nps6 orthologs in the rice (oryza sativa) pathogen, cochliobolus miyabeanus, the wheat (triticum aestivum) pathogen, fusarium graminearum, and the arabidopsis thaliana pathogen, alternaria brassicicola, resulted in reduced virulence and hypersensitivity to h(2)o(2). introduction of the nps6 ortholog from th ...200617056706
arabidopsis wrky33 transcription factor is required for resistance to necrotrophic fungal pathogens.plant wrky transcription factors are key regulatory components of plant responses to microbial infection. in addition to regulating the expression of defense-related genes, wrky transcription factors have also been shown to regulate cross-talk between jasmonate- and salicylate-regulated disease response pathways. the two pathways mediate resistance against different types of microbial pathogens, and there are numerous reports of antagonistic interactions between them. here we show that mutations ...200617059405
functional diversification of acyl-coenzyme a oxidases in jasmonic acid biosynthesis and action.the biosynthesis of jasmonic acid (ja) in plant peroxisomes requires the action of acyl-coenzyme a oxidase (acx). among the five expressed members (acx1-5) of the acx gene family in arabidopsis (arabidopsis thaliana), only acx1 is known to serve a role in ja production. here, we used transgenic promoter-reporter lines to show that acx1 is highly expressed in mature and germinating pollen, stem epidermal cells, and other tissues in which jasmonate-signaled processes occur. wound-induced ja accumu ...200717172287
gene cloning and characterization of a novel recombinant antifungal chitinase from papaya (carica papaya).a chitinase cdna clone (cpchi, 1002 bp) was isolated from papaya fruit, which encoded a 275 amino acid protein containing a 28 amino acid signal peptide in the n-terminal end. the predicted molecular mass of the mature protein was 26.2 kda, and its pi value was 6.32. on the basis of its amino acid sequence homology with other plant chitinases, it was classified as a class iv chitinase. an active recombinant cpchi enzyme was overexpressed in escherichia coli. the purified recombinant papaya chiti ...200717263465
the fus3/kss1 map kinase homolog amk1 regulates the expression of genes encoding hydrolytic enzymes in alternaria brassicicola.mitogen-activated protein (map) kinases have been shown to be required for virulence in diverse phytopathogenic fungi. to study its role in pathogenicity, we disrupted the amk1 map kinase gene, a homolog of the fus3/kss1 map kinases in saccharomyces cerevisiae, in the necrotrophic brassica pathogen, alternaria brassicicola. the amk1 disruption mutants showed null pathogenicity on intact host plants. however, amk1 mutants were able to colonize host plants when they were inoculated on a physically ...200717280842
ha-def1, a sunflower defensin, induces cell death in orobanche parasitic plants.plant defensins are small basic peptides of 5-10 kda and most of them exhibit antifungal activity. in a sunflower resistant to broomrape, among the three defensin encoding cdna identified, sf18, sd2 and hadef1, only hadef1 presented a preferential root expression pattern and was induced upon infection by the root parasitic plant orobanche cumana. the amino acid sequence deduced from hadef1 coding sequence was composed of an endoplasmic reticulum signal sequence of 28 amino acids, a standard defe ...200717375322
the map kinase kinase mkk2 affects disease resistance in arabidopsis.the arabidopsis mitogen-activated protein kinase (mapk) kinase 2 (mkk2) was shown to mediate cold and salt stress responses through activation of the two map kinases mpk4 and mpk6. transcriptome analysis of plants expressing constitutively active mkk2 (mkk2-ee plants) showed altered expression of genes induced by abiotic stresses but also a significant number of genes involved in defense responses. both mpk4 and mpk6 became rapidly activated upon pseudomonas syringae pv. tomato dc3000 infection ...200717506336
arabidopsis cytochrome p450 monooxygenase 71a13 catalyzes the conversion of indole-3-acetaldoxime in camalexin synthesis.camalexin (3-thiazol-2-yl-indole) is an indole alkaloid phytoalexin produced by arabidopsis thaliana that is thought to be important for resistance to necrotrophic fungal pathogens, such as alternaria brassicicola and botrytis cinerea. it is produced from trp, which is converted to indole acetaldoxime (iaox) by the action of cytochrome p450 monooxygenases cyp79b2 and cyp79b3. the remaining biosynthetic steps are unknown except for the last step, which is conversion of dihydrocamalexic acid to ca ...200717573535
sulfur-enhanced defence: effects of sulfur metabolism, nitrogen supply, and pathogen lifestyle.evidence from field experiments indicates differential roles of sulfur and nitrogen supply for plant resistance against pathogens. dissection of these observations in defined pathosystems and controlled nutritional conditions indicates an activation of plant sulfur metabolism in several incompatible and compatible interactions. contents of cysteine and glutathione as markers of primary sulfate assimilation and stress response show increases in arabidopsis thaliana upon infection, coinciding with ...200717853361
identification of acyltransferases required for cutin biosynthesis and production of cutin with suberin-like monomers.cutin and suberin are the two major lipid-based polymers of plants. cutin is the structural polymer of the epidermal cuticle, the waterproof layer covering primary aerial organs and which is often the structure first encountered by phytopathogens. suberin contributes to the control of diffusion of water and solutes across internal root tissues and in periderms. the enzymes responsible for assembly of the cutin polymer are largely unknown. we have identified two arabidopsis acyltransferases essen ...200717991776
regulation of tradeoffs between plant defenses against pathogens with different lifestyles.plants activate distinct defense responses depending on the lifestyle of the attacker encountered. in these responses, salicylic acid (sa) and jasmonic acid (ja) play important signaling roles. sa induces defense against biotrophic pathogens that feed and reproduce on live host cells, whereas ja activates defense against necrotrophic pathogens that kill host cells for nutrition and reproduction. cross-talk between these defense signaling pathways has been shown to optimize the response against a ...200717998535
cerk1, a lysm receptor kinase, is essential for chitin elicitor signaling in arabidopsis.chitin is a major component of fungal cell walls and serves as a microbe-associated molecular pattern (mamp) for the detection of various potential pathogens in innate immune systems of both plants and animals. we recently showed that chitin elicitor-binding protein (cebip), plasma membrane glycoprotein with lysm motifs, functions as a cell surface receptor for chitin elicitor in rice. the predicted structure of cebip does not contain any intracellular domains, suggesting that an additional comp ...200718042724
interplay between ja, sa and aba signalling during basal and induced resistance against pseudomonas syringae and alternaria brassicicola.we have examined the role of the callose synthase pmr4 in basal resistance and beta-aminobutyric acid-induced resistance (baba-ir) of arabidopsis thaliana against the hemi-biotrophic pathogen pseudomonas syringae and the necrotrophic pathogen alternaria brassicicola. compared to wild-type plants, the pmr4-1 mutant displayed enhanced basal resistance against p. syringae, which correlated with constitutive expression of the pr-1 gene. treating the pmr4-1 mutant with baba boosted the already elevat ...200818088307
myb72 is required in early signaling steps of rhizobacteria-induced systemic resistance in arabidopsis.colonization of arabidopsis thaliana roots by nonpathogenic pseudomonas fluorescens wcs417r bacteria triggers a jasmonate/ethylene-dependent induced systemic resistance (isr) that is effective against a broad range of pathogens. microarray analysis revealed that the r2r3-myb-like transcription factor gene myb72 is specifically activated in the roots upon colonization by wcs417r. here, we show that t-dna knockout mutants myb72-1 and myb72-2 are incapable of mounting isr against the pathogens pseu ...200818218967
anastomosis is required for virulence of the fungal necrotroph alternaria brassicicola.a fungal mycelium is typically composed of radially extending hyphal filaments interconnected by bridges created through anastomoses. these bridges facilitate the dissemination of nutrients, water, and signaling molecules throughout the colony. in this study, we used targeted gene deletion and nitrate utilization mutants of the cruciferous pathogen alternaria brassicicola and two closely related species to investigate hyphal fusion (anastomosis) and its role in the ability of fungi to cause dise ...200818310356
synthesis, characterization, spectral studies and antifungal activity of mn(ii), fe(ii), co(ii), ni(ii), cu(ii) and zn(ii) complexes with 2-(4- sulphophenylazo)-1,8-dihydroxy-3,6-napthalene disulphonic acid trisodium salt.complexes of the type na(6)[m(hl)(2)(h(2)o)(2)], where m= mn(ii), fe(ii), co(ii), ni(ii), cu(ii) and zn(ii) and na(3)h(2)l= 2-(4-sulphophenylazo)-1,8-dihydroxy 3,6 naphthalene disulphonic acid trisodium salt, have been synthesized and characterized by physico-chemical (elemental analyses, solubility, electrolytic conductance, magnetic susceptibility measurement) and spectral (uv-visible, ir, esr, powder x-ray diffraction) techniques for their structure and studied for their antifungal activity a ...200518365101
distinct roles of jasmonates and aldehydes in plant-defense responses.many inducible plant-defense responses are activated by jasmonates (jas), c(6)-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (aos) and hydroperoxide lyase (hpl) branches, respectively. in addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. past experiments to define the role of c(6)-aldehydes in plant defense resp ...200818382679
rlm3, a tir domain encoding gene involved in broad-range immunity of arabidopsis to necrotrophic fungal, we describe the rapid cloning of a plant gene, leptosphaeria maculans 3 (rlm3(col)), which encodes a putative toll interleukin-1 receptor-nucleotide binding (tir-nb) class protein, which is involved in defence against the fungal pathogen l. maculans and against three other necrotrophic fungi. we have, through microarray-based case control bulk segregant comparisons of transcriptomes in pools of col-0 x an-1 progeny, identified the absence of a locus that causes susceptibility in an-1. the ...200818397376
osbirh1, a dead-box rna helicase with functions in modulating defence responses against pathogen infection and oxidative stress.dead-box proteins comprise a large protein family with members from all kingdoms and play important roles in all types of processes in rna metabolism. in this study, a rice gene osbirh1, which encodes a dead-box rna helicase protein, was cloned and characterized. the predicted osbirh1 protein contains a dead domain and all conserved motifs that are common characteristics of dead-box rna helicases. recombinant osbirh1 protein purified from escherichia coli was shown to have both rna-dependent atp ...200818441339
dellas control plant immune responses by modulating the balance of jasmonic acid and salicylic acid arabidopsis, the flagellin-derived peptide flg22 elevates antibacterial resistance [1] and inhibits growth [2] upon perception via the leucine-rich repeat receptor-like kinase flagellin-sensitive 2 (fls2) [3]. della proteins are plant growth repressors whose degradation is promoted by the phytohormone gibberellin [4]. here, we show that della stabilization contributes to flg22-induced growth inhibition. in addition, we show that dellas promote susceptibility to virulent biotrophs and resistan ...200818450451
synergistic interactions between chitinase chicw and fungicides against plant fungal pathogens.antifungal activity of chicw and synergistic interactions between chicw with fungicides were investigated. conidial germinations of phytopathogenic fungi, alternaria brassicicola, botrytis elliptica, and colletotrichum gloeoporioides, were inhibited by chicw but a. longipes was not. in addition, chicw showed synergistic effect with fungicides switch (cyprodinil+fludioxonil) and tebuconazole to inhibit fungal conidial germinations. the level of synergism of chicw with tebuconazole was higher than ...200818467877
a rice serine carboxypeptidase-like gene osbiscpl1 is involved in regulation of defense responses against biotic and oxidative stress.serine carboxypeptidase-like proteins (scpls) comprise a large family of protein hydrolyzing enzymes that play roles in multiple cellular processes. during the course of study aimed at elucidating the molecular basis of induced immunity in rice, a gene, osbiscpl1, encoding a putative scpl, was isolated and identified. osbiscpl1 contains a conserved peptidase s10 domain, serine active site and a signal peptide at n-terminus. osbiscpl1 is expressed ubiquitously in rice, including roots, stems, lea ...200818571878
involvement of the pepper antimicrobial protein caamp1 gene in broad spectrum disease resistance.pathogen-inducible antimicrobial defense-related proteins have emerged as key antibiotic peptides and enzymes involved in disease resistance in plants. a novel antimicrobial protein gene, caamp1 (for capsicum annuum antimicrobial protein1), was isolated from pepper (c. annuum) leaves infected with xanthomonas campestris pv vesicatoria. expression of the caamp1 gene was strongly induced in pepper leaves not only during pathogen infection but also after exposure to abiotic elicitors. the purified ...200818676663
identification of plant defence genes in canola using arabidopsis cdna microarrays.we report the identification of novel defence genes in canola by using a cdna microarray from arabidopsis. we examined changes that occur in the abundance of transcripts corresponding to 2375 arabidopsis expressed sequence tags (selected for defence gene identification) following inoculation of canola plants with the fungal necrotrophic leaf pathogen, alternaria brassicicola. microarray data obtained from this cross-hybridisation experiment were compared to expression profiles previously obtaine ...200818761493
the group iii two-component histidine kinase of filamentous fungi is involved in the fungicidal activity of the bacterial polyketide ambruticin.we have shown that the plant pathogen alternaria brassicicola exhibited very high susceptibility to ambruticin vs4 and to a lesser extent to the phenylpyrrole fungicide fludioxonil. these compounds are both derived from natural bacterial metabolites with antifungal properties and are thought to exert their toxicity by interfering with osmoregulation in filamentous fungi. disruption of the osmosensor group iii histidine kinase gene abnik1 (for a. brassicola nik1) resulted in high levels of resist ...200919011080
differential profiling of selected defence-related genes induced on challenge with alternaria brassicicola in resistant white mustard and their comparative expression pattern in susceptible india mustard.the lack of availability of sources of resistance against alternaria brassicicola within the family brassicaceae has made oilseed mustard plants a target for one of the most damaging and widespread fungal diseases, alternaria black spot. of the other non-host-resistant/tolerant plants, sinapis alba, white mustard, is considered to be the most important apart from arabidopsis. to understand the defence response of s. alba upon incompatible interaction with this pathogen, a functional genomic appr ...200819019005
an important role of a bahd acyl transferase-like protein in plant innate immunity.salicylic acid (sa) is an important regulator of plant resistance to biotrophic and hemi-biotrophic pathogens. the enhanced pseudomonas susceptibility 1 (eps1) mutant in arabidopsis thaliana is hypersusceptible to both virulent and avirulent strains of the bacterial pathogen pseudomonas syringae. through positional cloning, the eps1 gene was isolated and found to encode a novel member of the bahd acyltransferase superfamily. pathogen-induced accumulation of sa and expression of pathogenesis-rela ...200919036031
heterotrimeric g proteins-mediated resistance to necrotrophic pathogens includes mechanisms independent of salicylic acid-, jasmonic acid/ethylene- and abscisic acid-mediated defense signaling.summary heterotrimeric g proteins are involved in the defense response against necrotrophic fungi in arabidopsis. in order to elucidate the resistance mechanisms involving heterotrimeric g proteins we analyzed the effects of the gbeta ( subunit deficiency in the mutant agb1-2 on pathogenesis-related gene expression as well as the genetic interaction between agb1-2 and a number of mutants of established defense pathways. gbeta (-mediated signaling suppresses the induction of salicylic acid (sa)-, ...200819054360
gdsl lipase-like 1 regulates systemic resistance associated with ethylene signaling in arabidopsis.systemic resistance is induced by necrotizing pathogenic microbes and non-pathogenic rhizobacteria and confers protection against a broad range of pathogens. here we show that arabidopsis gdsl lipase-like 1 (glip1) plays an important role in plant immunity, eliciting both local and systemic resistance in plants. glip1 functions independently of salicylic acid but requires ethylene signaling. enhancement of glip1 expression in plants increases resistance to pathogens including alternaria brassici ...200919077166
identification and functional analysis of brassicicene c biosynthetic gene cluster in alternaria brassicicola.the biosynthetic gene cluster of brassicicene c was identified in alternaria brassicicola strain atcc 96836 from genome database search. in vivo and in vitro study clearly revealed the function of orf8 and orf6 as a fusicoccadiene synthase and methyltransferase, respectively. the understanding toward the biosynthetic pathway promises construction of this type of diterpene compounds with genetic engineering.200919097780
rna silencing is required for arabidopsis defence against verticillium wilt disease.rna silencing is a conserved mechanism in eukaryotes that plays an important role in various biological processes including regulation of gene expression. rna silencing also plays a role in genome stability and protects plants against invading nucleic acids such as transgenes and viruses. recently, rna silencing has been found to play a role in defence against bacterial plant pathogens in arabidopsis through modulating host defence responses. in this study, it is shown that gene silencing plays ...200919098131
phylogenetic and transcriptional analysis of a strictosidine synthase-like gene family in arabidopsis thaliana reveals involvement in plant defence responses.protein domains with similarity to plant strictosidine synthase-like (ssl) sequences have been uncovered in the genomes of all multicellular organisms sequenced so far and are known to play a role in animal immune responses. among several distinct groups of arabidopsis thaliana ssl sequences, four genes (atssl4-atssl7) arranged in tandem on chromosome 3 show more similarity to ssl genes from drosophila melanogaster and caenorhabditis elegans than to other arabidopsis ssl genes. to examine whethe ...200919121120
arabidopsis gdsl lipase 2 plays a role in pathogen defense via negative regulation of auxin signaling.glip1 was isolated previously from arabidopsis, as a salicylic acid-responsive secreted gdsl lipase that functions in resistance to alternaria brassicicola [i.s. oh, a.r. park, m.s. bae, s.j. kwon, y.s. kim, j.e. lee, n.y. kang, s. lee, h. cheong, o.k. park, secretome analysis reveals an arabidopsis lipase involved in defense against alternaria brassicicola. plant cell 17 (2005) 2832-2847.]. to extend our knowledge of the roles played by glips in arabidopsis, we conducted functional studies of a ...200919146828
the phytopathogenic fungus alternaria brassicicola: phytotoxin production and phytoalexin elicitation.the metabolites and phytotoxins produced by the phytopathogenic fungus alternaria brassicicola (schwein.) wiltshire, as well as the phytoalexins induced in host plants, were investigated. brassicicolin a emerged as the most selective phytotoxic metabolite produced in liquid cultures of a. brassicicola and spirobrassinin as the major phytoalexin produced in infected leaves of brassica juncea (whole plants). in detached infected leaves of b. juncea, the main component was n'-acetyl-3-indolylmethan ...200919223049
histone monoubiquitination1 interacts with a subunit of the mediator complex and regulates defense against necrotrophic fungal pathogens in arabidopsis.this work examines the role of the arabidopsis thaliana ring e3 ligase, histone monoubiquitination1 (hub1) in disease resistance. loss-of-function alleles of hub1 show increased susceptibility to the necrotrophic fungal pathogens botrytis cinerea and alternaria brassicicola, whereas hub1 overexpression conferred resistance to b. cinerea. by contrast, responses to the bacterial pathogen pseudomonas syringae are unaltered in hub1 plants. hub1 mutants have thinner cell walls but increased callose a ...200919286969
a compatible interaction of alternaria brassicicola with arabidopsis thaliana ecotype dig: evidence for a specific transcriptional signature.the interaction of arabidopsis with alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. infection of most ecotypes, including the widely-studied line col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. this study examines an ecotype, dijon g (dig), which is considered sensitive to a. brassicicola.200919296849
disruption of glycosylphosphatidylinositol-anchored lipid transfer protein gene altered cuticular lipid composition, increased plastoglobules, and enhanced susceptibility to infection by the fungal pathogen alternaria brassicicola.all aerial parts of vascular plants are covered with cuticular waxes, which are synthesized by extensive export of intracellular lipids from epidermal cells to the surface. although it has been suggested that plant lipid transfer proteins (ltps) are involved in cuticular lipid transport, the in planta evidence is still not clear. in this study, a glycosylphosphatidylinositol-anchored ltp (ltpg1) showing higher expression in epidermal peels of stems than in stems was identified from an arabidopsi ...200919321705
identification of novel virulence factors associated with signal transduction pathways in alternaria brassicicola.alternaria brassicicola is an important, necrotrophic fungal pathogen that causes black spot disease on brassicas. in order to study pathogenicity mechanisms, gene deletion mutants were generated for 21 putative regulatory genes including kinases and transcription factors subjectively selected from the annotated a. brassicicola genome. except for ste12, the deletion of the snf1 kinase, xlnr, and crea homologues that control cell wall-degrading enzyme production did not significantly affect virul ...200919460100
accumulation of hydroxycinnamic acid amides induced by pathogen infection and identification of agmatine coumaroyltransferase in arabidopsis thaliana.hydroxycinnamic acid amides (hcaas) are secondary metabolites involved in the defense of plants against pathogens. here, we report the first identification of hcaas, p-coumaroylagmatine, feruloylagmatine, p-coumaroylputrescine and feruloylputrescine, in arabidopsis thaliana rosette leaves infected with alternaria brassicicola and the assignment of at5g61160 as the agmatine coumaroyltransferase (atact) that catalyzes the last reaction in the biosynthesis of the hcaas. feeding experiments with put ...200919521717
heat shock factors hsfb1 and hsfb2b are involved in the regulation of pdf1.2 expression and pathogen resistance in order to assess the functional roles of heat stress-induced class b-heat shock factors in arabidopsis, we investigated t-dna knockout mutants of athsfb1 and athsfb2b. micorarray analysis of double knockout hsfb1/hsfb2b plants revealed as strong an up-regulation of the basal mrna-levels of the defensin genes pdf1.2a/b in mutant plants. the pdf expression was further enhanced by jasmonic acid treatment or infection with the necrotrophic fungus alternaria brassicicola. the single mutant hsfb2b a ...200919529832
abscisic acid has a key role in modulating diverse plant-pathogen interactions.we isolated an activation-tagged arabidopsis (arabidopsis thaliana) line, constitutive disease susceptibility2-1d (cds2-1d), that showed enhanced bacterial growth when challenged with various pseudomonas syringae strains. systemic acquired resistance and systemic pathogenesis-related gene1 induction were also compromised in cds2-1d. the t-dna insertion adjacent to nine-cis-epoxycarotenoid dioxygenase5 (nced5), one of six genes encoding the abscisic acid (aba) biosynthetic enzyme nced, caused a m ...200919571312
the arabidopsis resurrection1 gene regulates a novel antagonistic interaction in plant defense to biotrophs and necrotrophs.we report a role for the arabidopsis (arabidopsis thaliana) resurrection1 (rst1) gene in plant defense. the rst1 mutant exhibits enhanced susceptibility to the biotrophic fungal pathogen erysiphe cichoracearum but enhanced resistance to the necrotrophic fungal pathogens botrytis cinerea and alternaria brassicicola. rst1 encodes a novel protein that localizes to the plasma membrane and is predicted to contain 11 transmembrane domains. disease responses in rst1 correlate with higher levels of jasm ...200919625635
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