Mechanisms of Heat Stress Tolerance in Wheat: Integrating Physiological, Biochemical, and Molecular Insights with Breeding Approaches
Ravi Ranjan
Department of Genetics and Plant Breeding, Lovely Professional University, Punjab, India.
Shiv Prakash Shrivastav *
Department of Genetics and Plant Breeding, Lovely Professional University, Punjab, India.
Harmeet Singh Janeja
Department of Genetics and Plant Breeding, Lovely Professional University, Punjab, India.
*Author to whom correspondence should be addressed.
Abstract
Wheat (Triticum aestivum L.) is a critical global food staple, but its productivity is increasingly threatened by climate change-induced heat stress (HS). A 1°C rise in temperature can reduce global wheat yields by approximately 6%. This paper reviews the multifaceted impacts of HS, including impaired germination, reduced photosynthetic capacity and reproductive failure. Key tolerance mechanisms involve the production of heat shock proteins (HSPs), which act as molecular chaperones and the activation of antioxidant defense systems to mitigate oxidative damage caused by reactive oxygen species (ROS). Physiological traits like stay-green duration and canopy temperature depression (CTD) are highlighted as effective selection criteria for developing thermotolerant cultivars. Furthermore, the integration of conventional breeding with molecular tools—such as QTL mapping and marker-assisted selection is essential for introgressing heat-tolerant traits from wild relatives and landraces into bread wheat to ensure future food security.
Keywords: Triticum aestivum, heat shock proteins, photosynthetic capacity, reactive oxygen species, QTL mapping, marker-assisted selection.