Bioenergetic cost of heat tolerance in wheat crop

Abstract

Decline in national wheat productivity, and stagnation of yield in the national Advanced Varietal Trials in the past decade are partly attributed to high temperature stress during the period of grain-filling. In view of the predicted global warming, terminal heat stress is likely to increase. Heat shock proteins (HSPs) synthesized to cope with the heat stress in different organisms are known to provide protection and repair the cellular damage caused by heat. The production cost of HSPs from different plant species-wheat, Arabidopsis, Phaseolus and maize ubiquitin was calculated based on their reported amino acid composition, and the production value of individual amino acids published earlier. Glucose required for the production of wheat HSP 101 was 20% higher compared to the storage proteins in wheat grains. Thus, incorporation of terminal heat tolerance into high-yielding cultivars will have an energetic cost, and would require additional carbon assimilates and N inputs.