Wheat is the most widely cultivated cereal and provides around 20% of the calories consumed by the world population. In a climate change scenario, the crop yield is negatively affected due to heat shock events (by 10-30%). In response to heat stress, a cascade of events is triggered at the molecular level, activating and repressing numerous genes. In this context, there are few studies focused on the response of wheat grains to heat stress, therefore, our research group shown that heat stress treatments during a short period of the grain-filling, decreased grain size and weight (from 16 to 30%) in wheat. In the present work Triticum durum was sown in greenhouse conditions in two seasons. The plants were exposed to heat stress for 4 days, starting ten days after flowering. An RNA-sequencing analysis on grain showed almost 4000 transcripts differentially expressed related with protein folding, photosynthesis and RNA metabolism. We identified a gene of the family of peptidylprolyl-isomerase, known as Rotamase, whose mRNA levels increased more strongly in wheat grains by heat stress treatment and its expression levels was validated by qRT-PCR. To functional analysis of this gene in thermotolerance processes of wheat grains, we developed and selected mutant lines of the Rotamase gene by CRISPR-Cas9 approach. Further functional characterization of this candidate gene will provide insights about its potential influence in the final grain weight under a heat stress condition and could contribute to mitigate the effects associated with the increase of the global temperature.

Acknowledgement. FONDECYT Postdoctorado 2015-2018 Nº3160336, FONDECYT Postdoctorado 2019-2022 Nº3190461.

THEME 3