Identification of resistance sources and expression level of defense-related genes in wheat against Bipolaris sorokiniana

Abstract

Spot blotch caused by Bipolaris sorokiniana, is one of the major diseases of wheat in the humid and warmer wheat growing areas of India. Among the eight wheat genotypes that were evaluated with diverse ten B. sorokiniana isolates, Chirya 7 was found highly resistant to spot blotch and BS-112 was most aggressive isolate in comparison to other isolates. Relative expression analysis showed that eight defense-related genes (chitinase, glucanase, PR-1, Lipid transfer protein, Serine palmitoyl transferase, UDP-glycosyl transferase, Translationally controlled tumor protein, dnaJ-like) in wheat were highly expressed in resistant genotype (Chirya 7) as compared to susceptible cultivar, Sonalika. Furthermore, chitinase gene was up regulated to maximum level (12.42 fold) at 72 hai (hours after inoculation) in the resistant genotype, Chirya 7. Similarly, pathogenesis related-1 protein gene was showed up regulation (8.31 fold) at 24 hai; and predicted dnaJ homolog subfamily C member 8-like gene showed high up regulation at 48 hai; UDP-glycosyltransferase (UGTs) gene was highly expressed at 24 hai and predicted serine palmitoyl transferase gene showed early expression (9.22 fold) in resistant genotype. Translationally controlled tumor protein (TCTP) gene was also highly expressed at early stage. Overall, Chirya 7 genotype had shown highest transcripts during host–pathogen interaction as compared to Sonalika against most virulent isolate of BS-112, thereby indicating that resistant genotype Chirya 7 was having various defense-related genes and could serve as potential donor for spot blotch resistance breeding in wheat.