Prospective protein markers for selection of heat tolerant potato cultivars

Abstract

Most of the commercially important cultivars of potato are well adapted to cool climates, whilst adversely affected by high temperatures. In order to develop a procedure for efficient screening of potato genotypes regarding heat tolerance, we investigated expression and accumulation of heat stress-related HSP17.6, HSP21, HSP101 and eEF1A proteins in various potato cultivars both in a controlled environment and field trials. Potato plants were grown in a climate-controlled chamber and exposed to prolonged heat stress (HS) in the stages of tuber initiation and early tuber bulking. Tuberization parameters were measured and prospective protein markers analyzed in collected leaf and minituber samples. In a field experiment, the potato was grown in the irrigated field in Zemun Polje (Serbia) and leaf samples for protein analyses were collected after high-temperature incidents in two extremely hot years (2011 and 2012). Besides, relevant growth and yield parameters were measured each year. Positive, linear correlation was determined between yield per plot and accumulation of HSP17.6, HSP101 or eEF1A under HS in examined potato cultivars, while negative correlation was determined between the height of primary shoots, as well as aboveground biomass, and accumulation of these three proteins. In other words, potato genotypes which accumulated higher amounts of HSP17.6, HSP101, and eEF1A under HS in the field, also had shorter primary shoots, lower above-ground biomass, and higher tuber yield. Our results indicated that among investigated proteins, HSP17.6, HSP101, and eEF1A might be considered as prospective protein markers for selection of heat tolerant potato genotypes.