Studies on the Accumulation of Drought-Induced Boiling Soluble Proteins (Hydrophilins) at Vegetative and Reproductive Phases of Drought Tolerant and Susceptible Cultivars of Triticum aestivum

Abstract

Drought is one of the major environmental constraints affecting the crops worldwide. Expression of boiling soluble proteins (BSPs) is of paramount importance, because they play important roles in the water stress responses and also in plant metabolism. In this study, the effect of drought on BSPs at vegetative (shoots) and reproductive (seeds) phases of drought tolerant (cv. ‘PBW 527’) and drought susceptible (cv. ‘PBW 343’) cultivars of Triticumaestivum were carried at three different developmental stages. The boiling soluble protein profiles of shoots and seeds were outlined via SDS-PAGE followed by immune-blot analysis using anti-HSP, anti-APase, anti-LEA, anti-SOD, anti-AQUA and anti-CAT antibodies. Western blot analysis revealed that expression of BSPs was modulated differentially in a stress, tissue, developmental stage and cultivar dependent manner. For instance, enhanced expression of seeds BSPs (APase, LEA, CAT, AQUA) was observed in the tolerant cv. ‘PBW 527’ after drought stress. However, no such enhancement was observed in the susceptible cultivar. Similarly, in shoots of cv. ‘PBW 527’, a substantial increase of BSP (SOD) expression was established after drought stress treatment, indicating their role in drought stress adaptation. Further, to gain an insight into the role of BSPs, a time course pre- and post-stress kinetic studies were also conducted in the seeds of tolerant and susceptible wheat cultivars. Based upon the observations, the possible role of boiling soluble proteins (hydrophilins) in water stress tolerance is discussed.