Siberian Journal of Life Sciences and Agriculture (Dec 2020)
INFLUENCE OF HIGH TEMPERATURES ON HEAT TOLERANCE AND SYNTHESIS OF HEAT SHOCK PROTEINS IN SPRING WHEAT AT THE INITIAL STAGES OF DEVELOPMENT
Abstract
Wheat is one of the agricultural crops that is subjected to temperature stress during ontogenesis and it is especially sensitive to action of the stress at the initial stages of wheat development. High temperatures restrict of growth, development and plant productivity. However, plants can to acclimate to temperature stress and have the adaptive mechanisms at the cellular and molecular levels. One of this adaptive mechanism is an increase of the synthesis of the heat shock proteins (HSPs), which functions are very important and various. The aim of this study was to determine the influence of different heat treatments (37 and 39 ºC for 1, 3, 6, 24 h and 50 ºC for 1, 3, 5 h) on the heat tolerance in spring wheat seedlings (Triticum aestivum L.) and synthesis of the HSPs (101, 70, 60 and 16.9 kDa) in shoots of the 4-day-old seedlings and leaves of the 8-day-old seedlings. Based on the findings, it is concluded that the 4-day-old and 8-day-old spring wheat seedlings are characterized by a similar response to heat stress at 50 ºC, however, 4-day-old seedlings are more resistant in the initial period of stress influence. The exposures at 37 and 39 ºC are suitable for acclimation of spring wheat at the initial stages of development (the 4-day and 8-day-old seedlings). These temperatures lead to a similar trend in the heat resistance of seedlings and the synthesis of HSPs in shoots and leaves. At the same time the content of HSP16.9 depends on the developmental stage of wheat. It is noted the synthesis of HSP16.9 in shoots, but not in leaves under normal conditions. It is concluded that the heat acclimation of the 8-day-old seedlings is a longer process (6-24 h of exposure at 37 and 39 ºC) compared with the 4-day-old seedlings (3-6 h of exposure at 37 and 39 ºC).
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