In Vitro Water Deficit Stress Induced Genotypic Alterations In Protein Profile Among Aromatic Rice Varieties

Abstract

Present investigation was carried out with an objective to study the in vitro genotypic response of three aromatic rice cultivars, viz. Pusa Basmati 1, Pant Sugandh Dhan 17, Taraori Basmati and one non aromatic Narendra 359 to water deficit stress using mature embryos as explants. The effect of water deficit was induced by sub-culturing calli on Murashige and Skoog medium supplemented with different concentrations of polyethylene glycol (PEG)-6000. Total protein content was found to be increased with increasing concentration of PEG-6000 in the medium. SDS-PAGE of somaclones showed over expression of polypeptides ranged from 29 - 205 kDa under higher stress levels, which in turn suggested that many proteins are specifically altered de novo under water stress as a part of the adaptive mechanism. Rice cultivar, Narendra 359 showed best response in terms of chlorophyll and higher total protein content along with activation of few specific polypeptides under water stress and thus, proved to be drought tolerant. The protein profiling was complemented by analyzing the genetic diversity of these varieties with random amplified polymorphic DNA (RAPD). RAPD profiles from the micro propagated plants showed polymorphism with similarity ranging from 0.46 to 0.76.