Vol. 12, Issue 10 (2023)

Author(s):
Dhanvarsha M, Saranya N, Infant Richard J, Mary Roshni A and Mohankumar S

Abstract:
Rice (Oryza sativa L.) is a widely grown cereal crop consumed by half of the world’s population. The Yellow Stem Borer (YSB), a monophagous pest causes yield loss of up to 25% in rice. It damages the crop in all stages, producing dead hearts in the vegetative stage and white ears in the reproductive stage. In response to stress, the plant's defence mechanism induces the accumulation of serotonin through the serotonin biosynthetic pathway. Serotonin has a major role in pest immunity and rendering the crop susceptible to pests. Therefore, this study aimed to analyse the single nucleotide polymorphism (SNP) of gene CYP71A1 involved in the serotonin pathway, in both susceptible and resistant varieties of YSB in rice. Two functional SNPs were identified at position 9581596 (G/A) and 9581369 (G/T) in the YSB susceptible and resistant varieties through multiple sequence alignment tool CLUSTAL omega. Further, modelling and docking studies were performed by I-TASSER server and Discovery studio software respectively to explore these mutations in the gene CYP71A1 that encodes Tryptamine 5-hydroxylase (T5H) enzyme and produces serotonin with its substrate tryptamine. The docking results showed that (T5H) in the susceptible variety (ASD16) showed high binding energy of -16.66 kcal mol^-1 compared to the resistant variety (TKM 6) -19.02 kcal mol^-1respectively. In addition alanine scanning mutagenesis was done using ABS scan promotes insight into the T5H binding site residue LEU (378) on tryptamine binding. The development of YSB resistant rice lines could be made possible through targeted gene editing of this region, alleviates the infestation of YSB and improves rice productivity.