Abiotic Stress, Crop Resilience and Food Security: A Comprehensive Review

Abstract

Abiotic stresses such as drought, salinity, extreme temperatures, flooding, nutrient imbalances, and heavy-metal toxicity are among the most important environmental factors limiting agricultural productivity across the globe. With the ongoing impacts of climate change, these stresses are becoming more frequent, intense, and prolonged, posing a serious challenge to sustainable crop production and global food security. This review provides a comprehensive overview of the physiological, biochemical, and molecular mechanisms that plants employ to cope with abiotic stress and discusses how these stresses affect the four pillars of food security: availability, access, utilisation, and stability. Particular emphasis is placed on key adaptive responses, including stress perception and signalling, hormonal regulation, osmotic adjustment, antioxidant defence mechanisms, and gene-regulatory networks that contribute to stress tolerance. Evidence from major cereal crops reveals that plant sensitivity to stress varies across developmental stages and that the combined effects of multiple stresses are often more damaging than individual stress factors. The review also highlights current and emerging approaches to enhance crop resilience, including conventional and molecular breeding, genome editing, improved agronomic practices, efficient water and nutrient management, soil health restoration, protected cultivation, digital agriculture, and climate-smart farming strategies. Ensuring food security under increasingly unpredictable climatic conditions will require an integrated approach that combines advances in genetics, sustainable crop management, natural resource conservation, socioeconomic support, and equitable access to innovative technologies. Future research should focus on understanding plant responses to multiple simultaneous stresses, improving genotype-by-environment predictions, developing adaptation strategies suitable for smallholder farming systems, and evaluating the effects of stress on crop nutritional quality.