Executive Summary : | Global climate change poses a significant threat to agricultural productivity and food security, with atmospheric CO₂ levels rising to over 400 ppm. As the world's population grows, the ability to maintain crop output and nutritional quality is severely hampered by heat stress. Increased atmospheric CO₂ benefits photosynthesis, biomass, and crop yield, but it also deteriorates grain quality in important crop plants like wheat and rice. Wheat, which accounts for 30% of the world's grain production, has experienced a decline in annual growth from 3% in the 1970s and 1980s to 0.9% in recent years due to multiple abiotic factors and climate change affecting wheat yield. Researchers have identified several QTLs and genes associated with drought stress tolerance in wheat through various approaches, including QTL interval mapping, GWAS, and comparative genomics. They have also introduced a QTL for drought tolerance to Indian bread wheat cultivars and developed drought-tolerant wheat lines. DNA methylation is a potential epigenetic mechanism that regulates plant development and stress-mitigation in crops. The study found extensive DNA methylation at single base resolution in two wheat cultivars under control and heat stress conditions. The current proposal extends previous works by exploring the role of DNA methylations and gene regulation during grain filling under elevated CO₂ and temperature combined. Heat-tolerant and susceptible genotypes will be grown under elevated CO₂, temperature, and the control environment (ambient), with whole genome bisulfite sequencing and transcriptome enabling identification of epigenetic determinant and expression regulation under elevated CO2 and temperature. |