Functional phenomics and genomics: Unravelling heat stress responses in wheat

Heat stress severely impacts wheat production by altering morpho-physiological traits, disrupting cellular physiological and biochemical attributes, and ultimately affecting the genetic makeup of the plant. Heat affects the thermosensitive traits of the vegetative and reproductive stages of wheat. Therefore, it is imperative to employ precise and expedite trait-based phenotyping as well genomics tools and crop breeding approaches to develop heat tolerant wheat cultivars. While trait-based breeding has been a time-consuming approach, it faces numerous challenges due to the labour-intensive, expensive, less accurate, environment-specific, and time-consuming process of screening, particularly for large numbers of genotypes. Nevertheless, recent breakthroughs in functional phenotyping, a platform that offers valuable insights into the dynamic responses of plants to heat stress. Conversely, functional genomics investigates genetic and epigenetic systems to identify and pinpoint gene variations related to specific traits. Therefore, this review summarizes heat stress effects on wheat at morphological, physiological and biochemical levels. Further, we highlight the potential of functional phenotyping that can rapidly detect wheat's physiological aspects in response to hot spells. We then finally highlight cutting-edge breeding strategies for enhancing heat tolerance in wheat, emphasizing an integrated approach that combines phenomics and genomics tools.