Vol. 8, Special Issue 8, Part L (2024)

Wheat (Triticum aestivum L.) is a crucial global cereal crop, contributing significantly to world grain production and trade. As a staple food for over 40 countries, it provides essential nutrition to a vast majority of the global population. Despite its significant role, wheat production faces challenges due to climate change, which is expected to raise ambient temperatures by 6 °C by the end of the 21st century. In India, where wheat is grown on 31.6 million hectares, climate change manifests as shorter winters and earlier summers, exposing crops to high-temperature stress during the grain filling stage. This terminal heat stress, particularly when temperatures exceed 31 °C, leads to substantial yield reductions and grain quality. Heat stress affects various wheat growth stages and physiological processes, resulting in reduced grain filling duration, premature leaf senescence, decreased photosynthetic capacity, and lowers grain quality parameters like reducing grain starch content (GAC), enhancing grain protein content (GPC) and total soluble sugars (TSS) etc. Additionally, wheat's sensitivity to biotic and abiotic stresses, including pests, diseases, and diminishing water resources, further exacerbates production challenges. To meet the increasing demand, driven by a projected population of 9.1 billion by 2050, annual wheat production must increase by 1.7%, yet current yield growth is only about 1% per year. Strategies to boost wheat productivity include enhancing heat tolerance through genetic improvements and stress mitigation techniques, such as the induction of heat shock proteins and antioxidative defense mechanisms. Although multiple genes have been engineered to enhance heat stress tolerance, their roles under various conditions require further exploration. New high-throughput phenomics techniques promise to measure complex traits associated with heat tolerance, enhancing traditional breeding approaches. Collaborative efforts among molecular biologists, plant physiologists, and breeders are essential, employing a comprehensive phenome-to-genome analysis to map traits accurately, introgress superior alleles, and clone major QTLs for heat tolerance. Integrating transgenic approaches with marker-assisted breeding programs and understanding mechanisms such as EF-Tu will be critical for developing heat-tolerant wheat varieties and improving crop yields in the face of climate change. Addressing these challenges is crucial for sustaining wheat production and ensuring food security globally.