Moisture Matters: How Water Shapes Pest Invasions and Disease Outbreaks?

Water availability and its distribution within plant tissues significantly influence photosynthesis, metabolism, transpiration, and crop susceptibility to pests and diseases. Both abiotic (e.g., drought, salinity, heat) and biotic stresses (e.g., insect pests, pathogens) disrupt plant water status, shaping plant responses across physiological, metabolic, and behavioral levels. These responses are highly variable and depend on stress intensity, plant adaptive capacity, pest or pathogen traits, and interactions with natural predators. This review presents the current understanding of the complex interplay between plant water dynamics, pest infestations, and disease development, with particular emphasis on their combined effects on crop resilience. Although considerable progress has been made in studying plant responses to individual abiotic or biotic stressors, the integrative role of water content in mediating plant-pest-pathogen interactions remains insufficiently explored. This review highlights how water stress can compromise plant structure and function, thereby increasing vulnerability to herbivory and infection. Critical research gaps are identified, particularly concerning simultaneous stress scenarios and the influence of soil properties on water-mediated responses. The review also examines the potential of advanced tools such as genome editing (CRISPR-Cas9), transcriptomics, and precision irrigation technologies for enhancing plant tolerance and reducing reliance on agrochemicals. The potential of biological control for mitigating pest pressure and alleviating water stress is discussed, including the use of natural enemies such as predatory insects and entomopathogenic fungi, which contribute to sustainable pest management. Overall, integrated water and pest management strategies are essential for maintaining crop productivity and resilience, particularly under the increasing challenges posed by climate change.