Heat stress responses of plants during adaptation to high temperature environments: A review of recent advances and insights

Abstract

ABSTRACT Plants, as sessile organisms, continuously encounter diverse environmental challenges, often experiencing multiple abiotic stresses during their development and growth. Among these stress events, heat has emerged as an increasingly severe factor because of global warming and currently poses a major threat to plant development, crop productivity, and agricultural sustainability. As a heat stress response, plants have evolved multilayered sensing and signaling systems that perceive heat cues and activate downstream protective and adaptive programs. This review summarizes recent knowledge regarding heat stress responses of Arabidopsis thaliana and major crops, including maize, rice, and wheat. We first outline the morphological, physiological, and molecular consequences of heat stress and then examine current models of heat perception and downstream regulatory networks. Particular emphasis is placed on second messenger signaling, transcriptional control, epigenetic regulation, post-transcriptional regulation, and heat memory. We also highlight stem cell homeostasis as an emerging component of heat adaptation that links stress signaling with developmental stability. Finally, we evaluate current strategies for improving crop heat tolerance, particularly during the reproductive stage, and discuss priorities for future research and breeding in a warming climate.