Plants, mycorrhizal fungi, and bacteria: a network of interactions
Bonfante P, Anca IA
Dipartimento di Biologia Vegetale dell' Università di Torino and Istituto di Protezione delle Piante del CNR, Sezione di Torino, Torino 10125, Italy.
This review focuses on interactions among plants, mycorrhizal fungi, and bacteria, testing the hypothesis whether mycorrhizas can be defined as tripartite associations. After summarizing the main biological features of mycorrhizas, we illustrate the different types of interaction occurring between mycorrhizal fungi and bacteria, from loosely associated microbes to endobacteria. We then discuss, in the context of nutritional strategies, the mechanisms that operate among members of the consortium and that often promote plant growth. Release of active molecules, including volatiles, and physical contact among the partners seem important for the establishment of the bacteria/mycorrhizal fungus/plant network. The potential involvement of quorum sensing and Type III secretion systems is discussed, even if the exact nature of the complex interspecies/interphylum interactions remains unclear.
Keywords:interactions among plants, mycorrhizal fungi, and bacteria,bacteria/mycorrhizal fungus/plant network.