Root exudates during perturbation: C-cycling and microbial responses define plant stress tolerance

Plants play a crucial role in providing oxygen to, and sequestering carbon from, the atmosphere. This sequestration is made possible by the rhizosphere microbiome - the community of microorganisms surrounding plant roots. This microcosm is fuelled by a phenomenon called root exudation, where plants release carbon compounds into the soil. Up to 20% of the carbon fixed by plants ends up in the soil, and half of this comes from root exudates alone. The process of root exudation is vital for soil health, microbial activity, and ultimately, carbon storage. Grasslands, covering a significant portion of our planet's land surface, are key players in the carbon cycle. Despite their ecological and agricultural importance, grasslands are under threat from climate change-induced stresses like drought, warming as well as pathogens and pests, whose range and seasonality are increasing with a warmer climate. Climate-change associated disturbances, such as those mentioned above, disrupt the delicate balance of carbon sequestration and impact soil microbial communities, which are essential for plant resilience to stress. My proposed research aims to shed light on this intricate web of interactions between plants, soil microbes, and environmental stressors. By examining the chemistry of root exudates and how it influences microbial communities, the study seeks to uncover the mechanisms behind plant recruitment of microbes and the resilience they can impart onto their hosts in the face of stress(es). Previous research has shown that plants adapt their root exudates in response to stress, priming the soil around plant roots to aid in recovery from stress. However, the specifics of these responses, especially under combined stressors like drought and warming, remain unclear. By studying grassland species with different growth strategies and exposing them to various stressors, the research aims to capture the complex interplay between plant physiology, exudate chemistry, and microbial activity. The findings from this study could have far-reaching implications across various sectors. From informing agricultural practices to guiding policy decisions on land management and climate change mitigation, the research promises to offer valuable insights into safeguarding grassland ecosystems. Moreover, by raising awareness of the intricate relationships between plants, soil, and climate, the research aims to engage the public in the urgent need for conservation efforts. In summary, this research will unlock fascinating biology below the ground, revealing the profound impact of plant-microbe interactions on ecosystem resilience and carbon sequestration. By understanding and harnessing the power of these natural processes, we can work towards a more sustainable future for generations to come.