Symbiosis between Chamaecrista fasciculata and nitrogen-fixing bacteria: a review

Nitrogen-fixing bacteria reside in nodules on roots of legumes. Within these nodules, they convert nitrogen gas to ammonia, a bioavailable form of nitrogen that the plant can use for nutrition. Although the vast majority of legumes form nodules, members of the Caesalpinioideae subfamily generally do not nodulate and are instead characterized by bacteria that remain in the infection thread during nitrogen fixation. As one of the few genera within this subfamily capable of nodulation, Chamaecrista p resents a rare opportunity to study the symbiosis between primitive legumes and nitrogen fixing bacteria. Observing nitrogen fixation in Chamaecrista allows for a greater understanding of less advanced mechanisms of nitrogen fixation which can potentially be conferred to plants that are not legumes. Previous literature regarding legume rhizobium symbiosis, however, is primarily focused on Papilionidae legumes. Therefore, this review aims to synthesizes literature on nodulation in primitive legumes to further characterize the process of nitrogen fixation in Chamaecrista.