Project description:Wall associated kinases (WAKs) have recently been identified as major components of fungal and bacterial disease resistance in several cereal crop species. However, the molecular mechanisms of WAK-mediated resistance remain largely unknown. Here, we applied the RNAseq approach to investigate the function of the maize gene ZmWAK-RLK1 (Htn1) that confers quantitative resistance to northern corn leaf blight (NCLB) caused by the hemibiotrophic fungal pathogen Exserohilum turcicum. A transcriptome analysis of near-isogenic lines (NILs) differing for ZmWAK-RLK1 revealed that several genes involved in the biosynthesis of the secondary metabolites benzoxazinoids (BXDs) were differentially expressed in the presence of ZmWAK-RLK1.
Project description:An indica rice cultivar IET8585 (Ajaya), resists diverse races of the Xanthomonas oryzae pv oryzae (Xoo) pathogen attack, and is often cultivated as bacterial leaf blight (blb) resistant check in India. Earlier we reported a recessive blb resistance gene mapped to the long arm of chromosome 5 in IET8585. To further understand the mechanism of recessive and durable resistance response, two indica rice genotypes namely, i) IET8585 (Ajaya), a disease resistant indica veriety from India and ii) IR24, a bacterial leaf blight disease susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under inoculated and un-inoculated conditions during seedling stage. Keywords: Bacterial leaf blight disease resistance mechanism
Project description:Some pathogen-derived effectors reprogram mRNA splicing in their host plant to regulate plant immune responses. The fungus Exserohilum turcicum is the causal agent of northern corn leaf blight, a damaging maize (Zea mays) disease. However, the low efficiency of genetic transformation of E. turcicum has hampered research on its effectors and whether E. turcicum effectors interfere with RNA splicing remained unknown. Here, using an alternative splicing (AS) reporter system, we identified the secreted protein EtEC81 (Exserohilum turcicum effector 81), which modulates the AS of maize pre-mRNAs and negatively regulates the pathogenicity of E. turcicum. EtEC81 physically interacts with EtEC81-interactiNG protein 1 (ZmEIP1), which associates with maize spliceosome components, regulating AS and positively regulating the defense response against E. turcicum. EtEC81 binding further enhanced the effect of ZmEIP1 on AS. Transcriptome analysis revealed 119 common genes with altered AS in maize plants transiently overexpressing ZmEIP1 or EtEC81, suggesting that these factors cause the mis-regulation of cellular activities and thus induce immune responses. We used RT-qPCR to verify representative AS events in the plants transiently overexpressing ZmEIP1 and EtEC81. Together, our results suggest that the EtEC81 effector targets ZmEIP1 to reprogram pre-mRNA splicing in maize.
Project description:Two-organism transcriptome profiling of infected seedling, adult leaf, and tassel demonstrated that both the host and pathogen exhibit organ-specific expression programs. Phenotypic screening of U. maydis mutants deleted for suites of secreted protein genes and maize growth mutants demonstrated organ-restricted tumorigenesis. Two-dye, competitive hybridizations were performed on Agilent oligo arrays. Keywords: maize, pathogen, fungus, Ustilago, organ-specificity
Project description:African Xanthomonas oryzae pv. oryzae strains seem most closely related to and share several genetic features with pathovar oryzicola despite causing symptoms of bacterial leaf blight. The ability of most Xanthomonas plant pathogenic bacteria to infect their host relies on the action of a specific family of type III effectors called the TAL effectors. These microbial transcription factors are injected into the plant and manipulate the host transcriptome upon binding to the promoters of plant genes. The genes whose induction is of benefit to the pathogen are called susceptibility genes. RNA profiling experiments in rice using the Malian Xoo strain MAI1 and in silico prediction of TAL effector binding sites were carried out to identify candidate targets of TalB, revealing OsTFX1, a bZIP transcription factor previously identified as a bacterial blight S gene, and OsERF#123, which encodes a subgroup IXc AP2/ERF transcription factor.
Project description:To further confirm whether the expression of NRT genes were influenced by pathogen infection, maize leaves were sampled at 0h, 24h, 40h, 60h and 96h post inoculation with wild-type strain Colletotrichum graminicola, the causing agent of maize anthracnose disease.
Project description:Phytophthora infestans is most notorious oomycete causing a devastating disease on tomato called late blight. The molecular mechanisms involved in host-parasite interaction is still unexplored well. Investigation of changes in gene expression profile after pathogen infection to find out the mechanisms involved in infection process
Project description:An indica rice cultivar IET8585 (Ajaya), resists diverse races of the Xanthomonas oryzae pv oryzae (Xoo) pathogen attack, and is often cultivated as bacterial leaf blight (blb) resistant check in India. Earlier we reported a recessive blb resistance gene mapped to the long arm of chromosome 5 in IET8585. To further understand the mechanism of recessive and durable resistance response, two indica rice genotypes namely, i) IET8585 (Ajaya), a disease resistant indica veriety from India and ii) IR24, a bacterial leaf blight disease susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under inoculated and un-inoculated conditions during seedling stage. Experiment Overall Design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during bacterial pathogen infection. We used two contrasting rice genotypes (IET8585 (Ajaya) blb resistant IR24 blb susceptible) differing in bacterial disease response. Plants were grown growth chambers and inoculated with bacterial pathogen on 18th DAS. Leaf sampling was done in both un-inoculated and inoculated plants at 3 time points. Two replications of microarray experiments were carried out by hybridizing the resistant samples against the susceptible samples.