Plant Pathogens in a Changing Climate: Disease Dynamics, Range Shifts, and the Future of Crop Protection

The global distribution and severity of plant disease is not static. Climate shapes every component of the plant-pathogen interaction: the physiology and dispersal capacity of the pathogen, the immune competence of the host, and the biology and geographic range of the vectors that connect them. As mean temperatures rise, precipitation patterns shift, drought frequency increases, and extreme weather events intensify, these three components are changing simultaneously and not always in predictable ways. The result is a disease landscape that is moving faster than existing surveillance infrastructure, resistance deployment strategies, and crop protection frameworks were designed to track. Pathogens previously confined to tropical and subtropical latitudes by winter cold are extending into temperate systems. Insect vectors are colonising regions where the viruses they carry were previously absent. Host plants under heat and drought stress are mounting weaker immune responses, creating windows of susceptibility that may not have existed in cooler, more stable climates. And in some cases, range-expanding pathogens are encountering host plant populations that have no prior evolutionary exposure and thus no standing resistance. Understanding these dynamics, mechanistically and at the population level, has become one of the most urgent applied questions in plant biology.The mechanistic basis of climate-immunity interactions is now beginning to be characterised, but the picture remains incomplete. High temperature suppresses NLR-mediated effector-triggered immunity in multiple crop-pathogen systems, a phenomenon tied in part to competition for HSP90 chaperone capacity between immune receptor folding and the heat stress response. Drought-induced accumulation of abscisic acid antagonises salicylate-dependent defences, creating conditions in which biotrophic and hemibiotrophic pathogens that would normally be held in check by the salicylate pathway encounter a weakened barrier — a dynamic increasingly described as drought-facilitated disease. Elevated atmospheric CO₂ alters host plant chemistry in ways that affect both pathogen growth and the chemical signals that prime plant defences, though the direction and magnitude of these effects vary substantially across pathosystems. These are not marginal perturbations — they alter the fundamental regulatory logic of the plant immune system under conditions that are increasingly the agricultural norm rather than the exception. At the same time, climate-driven changes in pathogen biology are occurring independently: altered sporulation windows, extended periods of infection-permissive humidity, accelerated generation times in warmer seasons, and shifts in the soil temperature and moisture conditions that govern the persistence and infectivity of soil-borne inoculum.Forecasting how these changes will compound and interact across diverse agroecosystems requires an integration of mechanistic plant biology, quantitative epidemiology, vector ecology, and climate science that the field has not yet fully achieved. Surveillance data on pathogen range expansion is accumulating rapidly, but mechanistic understanding of why particular pathogens are moving while others are not — and what host and environmental factors determine the outcome of new encounters — lags behind. Epidemiological models that incorporate climate projections are becoming increasingly sophisticated, but their predictive power depends on biological parameters that are often measured under controlled conditions poorly representative of the variable and compound stresses of real growing seasons. Tropical and subtropical agroecosystems, where climate change is in many cases most acute and where food security pressures are greatest, remain underrepresented in mechanistic studies relative to their epidemiological importance. This Research Topic aims to bring together researchers working across this full scope — from molecular biologists characterising temperature effects on immune signalling, to epidemiologists mapping pathogen range expansion, to agronomists evaluating the efficacy of existing crop protection tools under novel climatic conditions — to build a more integrated understanding of plant disease in a changing world.We welcome Original Research, Review, Mini Review, Methods, Hypothesis and Theory, Perspective, and Opinion articles addressing, but not limited to, the following themes:• Direct effects of elevated temperature, altered precipitation, drought, elevated CO₂, and extreme weather events on pathogen sporulation, survival, dispersal, and infection biology across fungal, oomycete, bacterial, and viral plant pathogens• Climate-mediated suppression of plant immune signalling: thermosuppression of effector-triggered immunity, drought and abscisic acid-mediated antagonism of salicylate-dependent defences, and CO₂-driven alterations in host plant chemistry and defence priming• Geographic range expansion of plant pathogens under warming and shifting precipitation regimes: case studies, underlying drivers, and implications for previously disease-free agroecosystems• Insect vector range shifts and their consequences for the geographic distribution and epidemiology of vector-borne plant viruses and other pathogens• New host-pathogen encounters arising from range-expanding pathogens meeting naive host populations, and the evolutionary and epidemiological dynamics of these emergent interactions• Phenological shifts and synchrony: how changes in the seasonal timing of host growth, pathogen activity, and vector population peaks alter disease outcomes and infection windows• Soil pathogen dynamics under changing temperature and moisture regimes: persistence of soil-borne inoculum, community composition shifts, and implications for root disease• Compound stress interactions: how the co-occurrence of climate stress and pathogen challenge alters disease trajectories relative to either stress alone, and the molecular mechanisms of cross-talk between abiotic and biotic stress signalling• Modelling and forecasting approaches integrating climate projections, pathogen biology, host susceptibility parameters, and vector ecology to anticipate future disease risk under different emissions scenarios• Adaptation of crop protection strategies to shifting disease landscapes: resistance gene deployment under evolving pathogen populations, adjustment of monitoring and threshold frameworks, and the durability of chemical and biological management tools under novel climatic conditions• Disease dynamics in tropical and subtropical agroecosystems and subsistence farming systems as climate envelopes shift and intensify• The role of plant-associated microbiome stability and resilience in buffering host plants against climate-driven increases in pathogen pressure Topic editors: Soibam Basanta Singh, Sunil Kumar Source: https://www.frontiersin.org/research-topics/83116/plant-pathogens-in-a-changing-climate-disease-dynamics-range-shifts-and-the-future-of-crop-protection