Plant responses to combined abiotic and biotic stresses

Abstract

Climate change has increased the frequency of extreme weather events, leading to the widespread occurrence of various abiotic stresses such as drought, salinity and temperature. Abiotic challenges often coincide with biotic stresses including pathogen and pest infestations. The frequent occurrence of such stresses, either individually or in combination, hinders crop growth, development, yield and quality. Plants have evolved diverse physiological and molecular adaptations to safeguard themselves against various stresses. However, plant responses to combined biotic and abiotic stresses are more complex and variable than responses to individual stresses, due to the intricate interactions among signaling networks and defense pathways. A clear understanding of how abiotic stresses influence pest and disease incidence as well as their severity is essential for developing strategies to mitigate the effect of combined stresses. Despite progress in individual stresses, there is a lack of comprehensive studies on the alterations in physiological, biochemical and molecular mechanisms of plants under combined stress conditions. This review aims to provide insights into plant responses to combined abiotic and biotic stress interactions and highlights the key morpho-physiological, biochemical, and molecular mechanisms, and presents recent case studies illustrating plant responses and effects under such combined stresses. In addition, this review highlights the integration of mechanistic insights with modern biotechnological and breeding strategies for enhancing plant tolerance to combined abiotic and biotic stresses. By providing a multi-dimensional framework that connects physiological, molecular, and computational analyses, it enables the identification of tolerant genotypes and serves as a comprehensive resource for plant breeders, molecular biologists, and agronomists to develop targeted strategies for improving crop resilience under combined stress conditions.