Comparative Study of Induction of Pathogenesis related proteins in pigeon pea varieties against Phytophthora drechsleri f.sp. cajani infection.

Plants encountered various infections in their natural environments, and they evolved a variety of defence systems to fend against the pathogen. One of them is the induction of pathogenesis-related proteins. In this study, the induction of pathogenesis-related proteins in four pigeon pea varieties, such as IPAC-02, ICPL 11260, Shrawani and Shweta were studied; upon phytophthora blight infection. The comparative study was done by morphological and biochemical analysis of all pigeon pea varieties against the Phytophthora infection. The result of morphological data indicates that the infection ICPL 11260 and Shrawani had significantly decreased root length; shoot length, number of leaves, fresh weight, and dry weight, compared to IPAC-02 and Shweta. The induction of PR protein as beta,1-3-glucanase, chitinase, phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase with their respective non-infected varieties at various stages was analysed from pre-infection to 1st day after infection up to 16th day after infection and the result showed higher PR activity in IPAC-02 and Shweta and peaked on the fourth and seventh day after infection respectively, whereas they were lowest activity in ICPL 11260 and Shrawani starting from the first day after infection. These results imply that the pattern of pathogenesis-related protein induction may play a crucial role in plant defence mechanisms, contributing to the selection of pigeon pea varieties' resistance to phytophthora infections.