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:Northern corn leaf blight (NLB), caused by the fungal pathogen Exserohilum turcicum, results significant yield reductions in infected corn. The first major locus conferring resistance to E. turcicum race 0, Ht1, was identified over 50 years ago, but despite widespread deployment the underlying gene has remained unknown. We employed map-based cloning to identify the Ht1 causal gene, which was found to be a coiled-coil nucleotide-binding, leucine-rich repeat (NLR) gene, termed PH4GP-Ht1. Transgenic testing confirmed that addition of the native PH4GP-Ht1 sequence to the susceptible maize variety PH184C resulted in resistance to E. turcicum race 0. A survey of the maize NAM genomes revealed that susceptible Ht1 alleles had very low to no expression, but overexpression of the susceptible B73 allele did not result in resistant plants, indicating that relatively minor protein sequence variations may underlie the resistance phenotype. Modeling of the PH4GP-Ht1 protein indicated that it has structural homology to the Arabidopsis NLR resistance gene ZAR1, and likely forms a similar homo-pentamer structure following activation. RNA-seq data from an infection time course revealed that one week after inoculation there was a threefold reduction in fungal biomass and a dramatic increase in DEGs when comparing mock to inoculated PH4GP-Ht1 transgenic plants and null plants. These results demonstrate that the NLR PH4GP-Ht1 is the causal gene underlying the NLB resistance phenotype of Ht1.
2022-10-03 | GSE206951 | GEO
Project description:Genomic Sequence Resource of Bipolaris maydis, Causal Agent of Southern Corn Leaf Blight of Corn Plants
Project description:The basidiomycete Ustilago maydis is the causal agent of corn smut disease and induces tumor formation during biotrophic growth in its host plant maize. The Usilago maydis genome harbors a homolog to the GATA transcription factors Nit2 and AreA that act as global regulators of nitrogen catabolite repression in filamentous model fungi Neurospora crassa and Aspergillus nidulans, respectively. We aimed at resolving the role of the Ustilago maydis Nit2 homolog for the utilization of complex nitrogen sources and pathogenicity.
Project description:Ascochyta blight causes severe losses in field pea production and the search for resistance traits towards the causal agent Didymella pinodes is of particular importance to farmers. Various microsymbionts are reported to shape the plants´ immune response. However, regardless their contribution to resistance, they are hardly included in experimental designs. In this project, the bi-directional effect of the symbionts´ (rhizobia, mycorrhiza) and the leaf proteome/metabolome of two field pea cultivars with varying resistance levels towards D. pinodes is delineated.
