Salt tolerance in rice: Present scenario and future prospects

Abstract

The crops worldwide are generally affected by the abiotic stresses like salinity, drought, extreme temperatures, etc., resulting in limitation on their productivity. However certain crop species have an extraordinary strength to survive in most difficult circumstances. Rice crop (Oryza sativa) is the staple food in most countries of the world. This crop is moderately resistant to7 salinity caused by ionic and osmotic mechanism. Ionic toxicity of Na+ largely competes with K+ for binding sites which are crucial to metabolic process. While as osmotic component relates to the buildup of Na+ and Cl- in the apoplastic space in leaf tissues. Elevated levels of Na+ in the apoplastic spaces causes dehydration and consequently shoots accumulate more Na+ than do roots. Thus shoots appear more sensitive to osmotic and ionic Na+ stress than roots. In this regard, morphological, physiological and genetic characters are discussed to raise rice plant for enhanced salinity stress tolerance and high yield potentiality.