Jeremy has worked on legumes his entire career, from his PhD at University of Guelph and Postdoctoral Scientist positions at plant biology institutes in Canada and the USA, where he became intrigued by the symbiosis between legumes and nitrogen-fixing soil bacteria called rhizobia.

Most legumes establish beneficial symbioses with nitrogen-fixing bacteria (rhizobia) in a process called nodulation, and with arbuscular mycorrhizal (AM) fungi, the latter interaction being shared with most land plants.

In both symbioses the microbes exchange signals with the host plant and then intracellularly invade the inner layers of the roots where nitrogen and/or phosphate is provided by the microbes in exchange for photosynthetic carbon supplied by the host. The association of rhizobia with legumes evolved from the more ancient AM symbiosis and the two symbioses share a signalling pathway.

In the case of rhizobia, access to the root cortex is gained through special structures called infection threads that initially form in root hairs and then are extended into the cells of the growing nodule where the bacteria are released and begin to fix nitrogen. In the case of AM fungi, the hyphae pass through the epidermis, then travel between cells and eventually extend into cortical cells as highly branched nutrient exchange structures called arbuscules.