Polyploidy alters plant genomes, phenotypes, and abiotic interactions. The effects of polyploidy on plant-biotic interactions however are less well known.
One important plant-biotic interaction is the legume-rhizobia mutualism, in which rhizobia fix atmospheric nitrogen in exchange for carbon. Forrester and Ashman propose a framework to understand how polyploidy directly enhances the quantity and quality of rhizobial symbionts hosted by legume plants, resulting in increased host access to fixed nitrogen. They synthesise trends from published studies, reveal gaps in current knowledge, and uncover areas ripe for future research. Although plant polyploidy enhances several key aspects of the mutualism, the underlying mechanisms remain unresolved.