Root–Root Interactions: Towards A Rhizosphere Framework

Plant scientists have made great progress in understanding molecular mechanisms controlling root responses to nutrients of arabidopsis (Arabidopsis thaliana) plants under controlled conditions. Simultaneously, ecologists and agronomists have demonstrated that root–root interactions involve more than competition for nutrients. Here, we highlight the importance of both root exudates and soil microbes for root–root interactions, ubiquitous in natural and agricultural ecosystems. We argue that it is time to bring together the recent insights from both scientific disciplines to fully understand root functioning in the real world.

TrendsMany studies have shown the importance of nutrient competition for plant performance in natural and agricultural ecosystems. However, results of several recent experiments show that these interactions cannot be explained by competition for nutrients alone. The rhizosphere has a key role in mitigating root–root interactions.Both the rhizobiome and root exudation affect root–root interactions either directly or via modification of resource availability to the plants. These pathways are closely connected because exudates affect different components of the rhizobiome, and vice versa.Combining the toolbox from molecular biology with ecological complexity will elucidate the functional interplay among the rhizobiome, root exudates, and the root, and its importance for plant performance in the real world.