Studying the micro-evolution of plant multi-stress resistance in high mountain forests at the interface of basic and applied ecology

• Applicant: Dr. Karin Schrieber
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 531846341

Global change continues to alter the composition of the stress matrix for an increasing number of wild plant species. How species respond to changes in multiple stressors on evolutionary time scales will dictate the likelihood of their persistence, the degree to which their natural distribution ranges will shift and the necessity for active conservation measures. Here we aim at studying the micro-evolution of plant multi-stress resistance with a holistic view covering 1) intrinsic heritable variation in plant traits, and 2) heritable variation mediated by locally co-evolved soil microbiota. Using Polylepis australis, an endangered tree species that inhabits one of the world’s most extremely climatically contrasting mountain ranges, we will study elevational divergence in combined heat and drought resistance. As these stresses vary not only substantially along the elevation gradient inhabited by Polylepis but are also predicted to increase under future climate change, our project will not only advance basic research into the functioning and evolution of wild plants in extreme environments but also have tangible implications for biodiversity conservation. We will approach our objectives with a single integrative experiment under highly controlled conditions, which have a near-natural design derived from existing long-term environmental field data. We will expose Polylepis sib-groups originating from low and high elevations at different mountain sites to individual and combined heat and drought stress, while growing them on sterile potting soils supplemented with either sterile inoculates, microbiota from low or microbiota from high origin field soils. We will assess data on plant growth, physiology, functional traits, the hydrophilic and lipophilic leaf metabolome, and the composition of root microbiota. For (1) intrinsic heritable variation in plant multi stress resistance. we expect that (1.1) plants originating from low elevations have higher heat and drought resistance; (1.2) there are trade-offs among and costs of the ability to resist different stressors, (1.3) combined stress requires unique plant responses that cannot be fully extrapolated from responses to individually applied stress. Moreover, we investigate (2) the extent to which association with co-evolved microbiota shapes heritable variation in plant stress resistance. We expect that (2.1) plant origin, soil origin and stress shape the composition of root microbiota in an interactive manner. We consider these differences as functionally important for plants if (2.2) plant growth performance under benign and stressful conditions is higher when plant and microbial elevation origin match, as compared to mismatching pairs. Local co-adaptation to increased heat and drought should manifest in (2.3) the lowest reduction of plant growth under stress for plants from low elevations inoculated with microbiota from low elevations.

• DFG Programme: Research Grants
• International Connection: Argentina
• Cooperation Partner: Dr. Paula Inés Marcora