Heat treatment affects regeneration, protein expression and genetic make-up of Vigna aconitifolia (Jacq.) Marechal

Abstract

High temperature affects diverse physiological, biochemical and molecular processes including gene expression and genetic stability. To demostrate this, primary leaves of moth bean were harvested from eight days old seedlings followed by heat shock treatment at 37, 42, 47 and 52 °C for 10, 20 and 30 min. The response of tissue for callusing was comparatively early in explants treated at 37, 42 and 47 °C for 10 min. However, regeneration was negatively affected by most of the heat treatments. A few polypeptides were found to be up regulated as well as down regulated with heat shock treatments. Some proteins were specifically regulated at higher temperatures of 42° and 47 °C. Two polypeptides were also up regulated in the protein profiling of callus; however, these were different than the once observed in protein profiling of leaf explant immediately after heat treatment. Moreover, these bands were found in only one treatment each, viz. one in 20 min of 47 °C (100 kD) and another in 30 min of 47 °C (36.7 kD). These may be expected to be consequence of genetic change (mutation). RAPD analysis further revealed that plantlets obtained at 47 °C generated a novel band indicating mutagenic effect of heat shock treatment.