Title: Genome-wide investigation of 20S proteasome family genes and their relevance to heat and drought tolerance in common wheat

Biography:

Sachin Kumar is Assistant Professor of Genetics and Plant Breeding at Chaudhary Charan Singh University, Meerut, India. His research area covers Plant Genomics and Molecular Breeding in cereal crops particularly wheat, which include trait discovery and phenotyping, high-throughput SNP genotyping, construction of high-density genetic maps, physical and radiation hybrid maps, comparative mapping, QTL interval mapping, genome-wide association studies (GWAS), development of molecular markers, marker-assisted selection for biotic and abiotic stress-responsive traits. He has been NSERC Visiting Fellow under Canadian Government Laboratories Program at Agriculture and Agri-food Canada (AAFC), Swift Current, Saskatchewan, Canada.

Abstract

The genes encoding α- and β-type subunits of 20S proteasome core protease are integral components of 26S proteasome complex in the ubiquitin-proteasome system (UPS). The 20S proteasome represents a catalytic particle that cleaves cytotoxic, denatured, damaged and unwanted proteins in an ATP/ubiquitin-dependent non-lysosomal pathway and is known to impart thermotolerance in model plants. In the present study, we identified a family of 67 genes (including 34 TaPA and 33 TaPB genes) encoding α- and β-subunits of 20S proteasome in bread wheat (Triticum aestivum L.). These genes were distributed on all the 21 wheat chromosomes, majority of them being in triplicate homoeologues. These wheat genes were orthologous to corresponding rice and Arabidopsis genes. The proteins encoded by each of the TaPA and TaPB genes contained 20 different motifs. These 20 motifs were present in corresponding proteins of Arabidopsis and rice. Phylogenetic analysis placed these genes in seven clusters, each with one of the seven α (α1-7) and one of the seven β (β1-7) subunits. Expression analysis suggested that 10 of the 67 genes were involved in heat stress response, whereas four genes were involved in drought tolerance at the seedling stage. Nine (9) genes were expressed under both heat and drought suggesting their involvement in response to multiple abiotic stresses. Future research on TaPA/TaPB genes will help in the development of climate-resilient wheat cultivars.

FIG. Schematic representation of the steps and programs used to identify 20S proteasome family genes in bread wheat.