Adjective modifier

• bacterial: The organism Rhizobia are bacterial symbionts of legumes ( plants in the family Fabaceae ).

• fungal: Fungal symbionts produce ascospores but they do not initiate independent new growth.

Noun used with modifier

• legume: The legume symbiont, Sinorhizobium meliloti, is tremendously important for fixing nitrogen from the air into plant roots and the soil.