Heat Stress Tolerance in Crops: New Frontiers for Climate-ready Agriculture
Subarnna Keshari Haripriya Padhan *
Department of Agricultural Extension, Palli Siksha Bhavana, Visva-Bharati, Sriniketan, West Bengal, India.
Ramayanam Surya Vardhan Raju
Department of Agronomy, Annamalai University, Tamil Nadu, India.
Harish H. Deshpande
Faculty of Agriculture, Warer and Land Management Institute, (WALMI), Chhatrapati Sambhajinagar 431005, Maharashtra, India.
Prasamsa Ramayanam
Department of Biotechnology, Vignan Foundation for Science Technology and Research, Andhra Pradesh, India.
Mriganka Barman
Department of Agricultural Economics, Assam Agricultural University, Jorhat, India.
Abhishek Ranjan
Department of Agronomy, PGCA, Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar-848125 India.
Himanshu Yadav
Department of Plantation Spices Medicinal and Aromatic Plants, Mahatma Gandhi Udyanikee Evam Vanikee, Vishwavidyalya, Sankara-Patan, Durg (C.G), India.
*Author to whom correspondence should be addressed.
Abstract
Global agriculture faces an unprecedented challenge as rising temperatures, driven by anthropogenic climate change, increasingly compromise crop productivity and food security. Heat stress—defined as an elevation in temperature beyond the threshold that disrupts normal plant growth and development—threatens all major staple crops, including wheat, rice, maize, soybean, and grain legumes, with potentially catastrophic consequences for yields. This review synthesises current knowledge on the physiological, biochemical, and molecular mechanisms underlying heat stress responses in crop plants, while charting the most promising frontiers for developing climate-ready cultivars. The review examines how elevated temperatures impair membrane integrity, photosynthetic efficiency, and reproductive processes, and explores the complex signalling networks orchestrated by heat shock proteins, heat shock transcription factors, and epigenetic regulators that underpin acquired thermotolerance. It further evaluates the contribution of genetic, genomic, transgenic, and CRISPR-based approaches to improving heat tolerance, alongside agronomic interventions. Special attention is given to the integration of multi-omics platforms, high-throughput phenotyping, and genomic selection in accelerating the development of heat-tolerant varieties. The review identifies critical knowledge gaps—including the poorly understood role of thermosensors, non-coding RNAs, and combinatorial stress interactions—and proposes a roadmap for research that bridges fundamental plant science with applied crop improvement. Given that current trajectories of global warming could reduce yields of key staples by 2–6% per decade, investment in heat-tolerant crop development is both scientifically urgent and ethically imperative.
Keywords: Heat stress, thermotolerance, heat shock proteins, climate change, crop improvement, reactive oxygen species, food security