Challenged (by) parasites: Acclimation kinetics of a plant-plant-pathosystem

Charline Gennat ¹, Susann Wicke ¹

Organismal Plant Interactions Group, Westfälische Wilhelms-Universität Münster, Institute for Evolution und Biodiversity, Münster, Germany ¹

Plants are constantly exposed to diverse biotic and abiotic stresses, which vary in both duration and intensity. To survive, they have developed sophisticated acclimation mechanisms that involve changes in gene expression, metabolism, and physiology. While much research has focused on single stressors, plants in natural environments often encounter multiple simultaneous stresses, resulting in interactions that can either amplify or mitigate their overall impact on plant survival and adaptation. This study investigates the effects of combined stresses on Arabidopsis thaliana, integrating abiotic stresses (cold, heat, and high light) with biotic stress caused by parasitism from the holoparasitic plant Phelipanche ramosa. Physiological responses, such as photosynthetic efficiency and reactive oxygen species (ROS) levels, were analyzed in conjunction with transcriptomic data to elucidate acclimation mechanisms. The role of plastid-mediated stress responses was further examined using Arabidopsis mutants deficient in genes involved in acclimation (cp31a, cp29a, cp29b). Additionally, the research explored how the loss of photosynthesis in Phelipanche ramosa influences its response to abiotic stresses. This dual-stress pathosystem provides a unique framework for studying the interplay between host and parasite under environmental challenges. The results reveal that parasitism modifies the host's stress acclimation responses, with Arabidopsis mutants displaying varying resilience to abiotic stresses. For example, cp31a mutants exhibited heightened sensitivity to cold, while parasitized wildtype and cp29a mutants demonstrated improved resilience to heat. Intriguingly, Phelipanche ramosa employed distinct survival strategies depending on the host genotype and stress conditions, activating both conserved and unique acclimation genes under cold stress. These findings highlight the complexity of stress interactions and provide new insights into the adaptive strategies of plants and their parasites under environmental stressors. This research underscores the importance of studying combined stress responses to deepen our understanding of plant resilience and adaptation in the context of a changing environment.

Main author career stage: PhD student

Contribution type: Poster

First choice session: 4. Structure, physiology, and development

Second choice session: 2. Ecology