Bottom-up perspective – The role of roots and rhizosphere in climate change adaptation and mitigation in agroecosystems

Background and Aims: Climate change is happening and causing severe impact on the sustainability of agroecosystems. We argue that many of the abiotic stresses associated with climate change will be most acutely perceived by the plant at the root-soil interface and are likely to be mitigated at this globally important interface. In this review we will focus on the direct impacts of climate change, temperature, drought and pCO2, on roots and rhizospheres. Methods and Results: We consider which belowground traits will be impacted and discuss the potential for monitoring and quantifying these traits for modelling and breeding programs. We discuss the specific impacts of combined stress and the role of the microbial communities populating the root-soil interface, collectively referred to as the rhizosphere microbiota, in interactions with roots under stress and discuss the plastic responses to stress as a way of adapting plants to climate change. We then go on to discuss the role that modelling has in understanding this complex problem and suggest the best belowground targets for adaptation and mitigation to climate change. We finish by considering where the main uncertainties lie, providing perspective on where research is needed. Conclusion: This review therefore focuses on the potential of roots and rhizosphere to adapt to climate change effects and to mitigate their negative impacts on plant growth, crop productivity, soil health and ecosystem services.