Heat-induced Expression of Protein Synthesis Elongation Factor 1A Associated with Potato Heat Tolerance

Abstract

Potato is a worldwide food crop and ranked as the world’s fourth most consumed food after rice, wheat, and maize. Belongs to cool-season crops, wherefore high temperatures have negative impact on economic yield and tuber quality. High temperatures affect morphogenesis of potato plants grown in the field as well as in controlled artificial environment. First step in the present study was to investigate the effects of high-temperature on tuberization in two in vitro potato cultivars, Désirée and Festival. Furthermore, we exposed these two tuberizing potato cultivars to mildly elevated temperatures (30/24°C, day/night) for one weeks and compared with plants grown under optimal conditions (20/18°C), using an ex vitro system. In our work, we also tested seven potato cultivars in the field under most favorable condition (~22oC) and under high-temperature condition (~35oC). We have investigated high-temperatures induced expression of translation elongation factor (eEF1A) in all potato cultivars growth in different conditions. eEF1A is a group of highly conserved proteins that play a central role in the elongation phase of protein biosynthesis, and also shows chaperone activity in protecting other proteins from aggregation caused by high temperatures. Using 1D-PAGE and Western blott analysis, we are determined significant differences in accumulation of eEF1A among potato cultivars. Also, qPCR revealed that elevated temperature had a profound impact on tuber mRNA expression of eEF1A isoforms. Our research shows that potato eEF1A proteins may play an important role in the process of tuberization under high-temperature conditions and development of heat tolerance by acting as molecular chaperone.