Physiological Mechanisms of Crop Responses to Climate-Related Abiotic Stresses: A Review
Babu Kakumanu *
Department of Botany and Microbiology, Faculty of Botany, Acharya Nagarjuna University, Nagarjuna Nagar – 522510, Guntur, Andhra Pradesh, India.
R VijayKumar
Department of Botany and Microbiology (M.Sc. Forestry Course), Faculty of Forestry, Acharya Nagarjuna University, Nagarjuna Nagar – 522510, Guntur, Andhra Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
The accelerating trajectory of climate change poses unprecedented challenges to global agricultural systems, with crop physiological processes at the nexus of environmental stress and food security outcomes. This review synthesises current understanding of the physiological and molecular mechanisms by which major crops respond to the principal abiotic stresses associated with a changing climate, namely drought, heat, cold, and salinity, as well as their increasingly common combined occurrences. Stomatal regulation, photosynthetic apparatus modification, reactive oxygen species (ROS) metabolism, osmotic adjustment, and hormone-mediated signalling networks are examined as core adaptive mechanisms across crop species. The review further evaluates the role of epigenetic regulation and transcriptional reprogramming in mediating stress memory and acclimation. Literature for this review was identified through systematic searches of the major academic databases. Searches were conducted with a primary focus on literature published between 2006 and 2026. Evidence from global yield analyses demonstrates that existing crop varieties are being progressively exposed to stress intensities that exceed their physiological tolerance thresholds, with temperature increases and water-deficit events being the predominant drivers of production losses across cereal, legume, and oilseed crops. Key insights also include the dual role of ROS as damaging agents and versatile signal molecules, the integrative function of abscisic acid (ABA) in drought and osmotic stress responses, the acute sensitivity of reproductive development to brief heat events, and the critical role of ion homeostasis under salinity stress. An assessment of adaptive strategies—encompassing conventional breeding, molecular and genomic approaches, and agronomic management—underscores the urgency of translating mechanistic physiological knowledge into field-relevant crop improvement. This review identifies critical research gaps and highlights priority areas for future investigation to underpin food system resilience in the face of continuing climate change.
Keywords: Abiotic stress, heat stress, drought stress, salinity, reactive oxygen species, crop improvement, climate change, food security