Morpho-physiological and proteomic analysis to identify and characterise the traditional rice genotypes for drought tolerance

Abstract

Rice is the major staple food for one-third of the world’s population. Rice requires high amount of water as compared to other cereal crops. In this context, we screened traditional rice genotypes collected from RARS, Pattambi and Ambalavayal for drought tolerance. Based on the morpho-physiological characters, the plants which showed wilting symptoms were screened according to international standard i.e., IRRI leaf score 7.0. The genotype which showed no wilting symptom even after 90% of the plants were showing wilting was identified as tolerant and the plant which showed early wilting symptom was identified as susceptible genotype. The genotype Chuvanna Modan has taken 25 days and the genotype Parambuvattan has taken only 10 days for wilting. After 90% of plants reached IRRI score 7.0 phenotypic observations i.e., electrical conductivity, measurement of stomatal conductance and transpiration rate using Infra red gas analyser were recorded. Root traits were also measured. The identified tolerant and susceptible genotypes were further subjected to 2D gel electrophoresis to identify and characterize the differentially expressed proteins for drought tolerance. Totally four differentially expressed protein spots were identified in Chuvanna Modan. The differential protein spots were sequenced by Matrix Assisted Laser Desorption/Ionization–Time of Flight Mass Spectrometry (MALDI–TOF/MS). Spot 1 and 2 were identified as ribulose bisphosphate carboxylase small subunit, spot 3 was identified as Protein tyrosine phosphatases and spot 4 was identified as Photosystem II stability/assembly factor HCF136.