Impact of Seed Priming on Proline Content and Antioxidant Enzymes to Mitigate Drought Stress in Rice Genotype

Abstract

Drought is one of the major problems of crop production in most of the countries, particularly in rice growing areas. Rice (Oryza sativa L.), is one of the major food grain cereal crops of the Indian and the world subcontinent. It belongs to the family Graminae (Poaceae) and is a model system for cereal biology because of its smaller genome size of 430 Mb that spans across 12 chromosomes. The rice varieties in this study showed differential responses for proline accumulation and enzymatic activities measured. The scavenging system in drought tolerant variety nagina-22 exhibited higher CAT, POD and SOD activities, than in the drought susceptible variety (pusa sugandh-5) drought-susceptible variety, PS-5 was markedly affected even at the lowest drought level used. The activity of antioxidant enzymes CAT, POD and SOD in the drought tolerant and drought susceptible varieties increased markedly during drought stress. Drought tolerance of the rice varieties associated with build up of antioxidant enzymes and proline. Among the biotic elicitors, MJ was found to be the most effective priming reagent, followed by PBZ. Present findings could be explored further to mitigate drought stress in order to improve rice yield in dry land areas.