Investigating the role of cystatin in conferring stage dependent resistance against Karnal bunt of wheat

Abstract

Two wheat varieties, one highly resistant (HD29) and another susceptible (WH542) and their recombinant lines were taken for expression profiling of cystatins at three stages (WS1, WS2 and WS3) of the developing spikes. Different biochemical and immunological techniques like protease inhibitor assay, ELISA, DOT-BLOT immunoassay and SDS-PAGE analysis were employed to reveal the relationship of cystatin expression with stage dependent resistance (P<0.01). Interestingly, in all the genotypes cystatin expression was the highest at WS2 stage which is most susceptible to Karnal bunt (KB) pathogen. Expression was higher in the resistant recombinant inbred lines than in the susceptible ones (P<0.0001). Percent disease severity results were also in accordance with cystatin expression studies and thus suggesting a direct role of cystatins in providing resistance against KB. Based on the presence of potential component markers like cystatins which are involved in defence, identification of resistant wheat germplasms can prove to be an important strategy for successful KB management.