Identification and characterization of genes for hypersensitive response in rice magnaporthe oryzae interaction

Abstract

Hypersensitive response can be explained as the innate defence mechanism of the plant which causes rapid death of cells at the area of pathogen ingress with an intend to restrict the pathogen colonization to a specific boundary. In our present study, 204 genes having significant role in hypersensitive response were identified in rice (Oryza sativa). Unlike animals, no gene families are established to execute cell death in plants, hence among all the identified genes, two gene families, i.e., metacaspases which belong to C-14 proteases and BAG genes were further extensively analyzed. Available genomic and transcriptomic resources tremendously helped to understand the role of metacaspases and BAG genes in wild and cultivated Oryza species. Further, the expression of both gene families was studied in response to blast disease caused by Magnaporthe oryzae. Early activation and upregulation of metacaspases genes were observed in response to M.oryzae infection which indicates its role in the regulation of cascade of the systematic stress response. Subsequently, co-expression network w developed to understand the gene interactions and regulation. In addition, extensive haplotypic evaluation of all the hypersensitive response related genes performed using whole genome resequencing information available for over four thousand diverse rice genotypes highlighted evolution, allelic diversity and potential sources for breeding applications. The information generated here will be helpful to better understand the genomic landscape of genes involved in hypersensitive response, their precise regulation and evolution and consequently provide the basis for the development of disease-resistant cultivars. newline