Heat stress in cultivated plants: nature, impact, mechanisms, and mitigation strategies—a review

TLDR

Rising global temperatures from human activity cause heat stress that damages plant growth, physiology, and yields, threatening ecosystems and food security. The study aims to deepen knowledge of plant responses to heat stress to guide mitigation strategies and distinguish it from drought stress. Researchers use conventional breeding, biotechnological and molecular methods, along with agronomic practices such as optimized sowing, seed priming, microbial treatments, nutrient and water management, and osmoprotectant applications to develop heat‑tolerant crops.

Abstract

The progressive increase in the earth’s temperature due to anthropogenic activities is a major concern for humanity. The ensuing heat stress (HS) severely impacts plant growth, endangering ecosystem quality and world food security. Plant growth, physiological processes and final amount of edible products are affected by HS to an extent that reflects the physical damages, physiological commotions and biochemical alterations incurred at various growth stages. Therefore, a better understanding of plant behaviour in response to HS has pragmatic implications for devising counter-measures, alleviation strategies, and for acknowledging the differences between HS and the companion drought stress. Conventional breeding, biotechnological and molecular approaches are used to develop HS tolerant genotypes in plant species bred for food/feed uses. Recent achievements in the omics techniques result in a better knowledge of the molecular mechanisms involved in HS. However, shrewd management of crop practices is still helpful to improve plant resilience to HS. Suitable sowing time, seed priming, bacterial seed treatment, nutrient and water management, exogenous application of osmo-protectants, and conservation of soil moisture are important tools to improve plant behaviour under the critical HS scenarios determined by climate change and global warming.