Abstract

Wheat is the most widely cultivated cereal and an essential component of global food security. In a climate change scenario, the crop yield is not only affected by the increase of the mean of surface global temperature, also by the increase in the frequency of extreme heat events. High temperatures during grain-filling could impact on yield-components, weight and quality of grains. In this work, we characterize at the molecular and physiological level the response of wheat grain exposed to heat stress during the grain-filling. Triticum durum seeds were sown in greenhouse and field conditions. Ten days after flowering plants were exposed to heat stress during 4 days, and then returned to control conditions until physiological maturity. We found a reduction in the final grain weight from 30% to 16% and alterations in the starch level without affecting seeds viability. RNA-sequencing analysis on grain identified almost 4000 transcripts differentially expressed related with protein folding, photosynthesis and RNA metabolism. Functional annotations of these genes included heat-shock protein, peptidylprolyl-isomerase, alpha-amylase inhibitor, glutenin, alpha-gliadin, redox and MYB-factor. Further functional characterization of candidate genes will provide insights about its potential influence in the final grain weight under a heat stress condition.