Abstract
Oomycete pathogen, Phytophthora capsici is devastating for black pepper (Piper nigrum L.) and causes foot rot disease at all stages of plant growth. Phytophthora secretes a glucanase inhibitor protein (GIP), which is capable of inhibiting defence proteins like endoglucanases. In this particular study Quantitative PCR analysis, molecular docking studies and analysis of sequences of Glucanase inhibitor protein and beta-1,3 glucanse genes were done mainly depending on the data derived from Phytophthora capsici whole genome sequencing and Piper colubrinum RNA-sequencing (RNA-Seq). Amino acid sequence length of GIP gene from P. capsici was about 353 amino acids and that of glucanase pcEGase gene from P. colubrinum was about 312 amino acids. GIP gene from P. capsici showed high level of expression at early hours of the inoculation time period and pcEGase gene showed high level of expression at 16 hpi. High level of expression of pcEGase gene at 16 hpi is an indication that the GIP gene is successfully inhibited by the glucanase protein from the plant. Moreover insilico studies gave some hint on the importance of certain sites on the surfaces of both interacting proteins that might be having a role in binding of the two proteins and subsequent reactions thereof. Insilico analysis also conclusively proved that inhibition of glucanase inhibitor protein is mainly caused by recognition of an arginine as well as an isoleucine residue during the interaction of the two proteins.