Changfeng Zhang is a postdoctoral researcher at Lawrence Livermore National Laboratory in the U.S. He studies the arbuscular mycorrhizal-associated microbiome to understand its functional roles in plant-mycorrhiza symbiosis. He obtained his Ph.D. from the Department of Environmental Biology at Utrecht University, the Netherlands. He conducted his doctoral research on the microbial interactions in soil and rhizosphere and their impact on litter decomposition, mycorrhizal associations and plant growth at both Agroscope (Zurich, Switzerland) and Utrecht University. He holds a master’s degree from the Chinese Academy of Medical Science and Peking Union Medical College, where he studied the culturable bacterial diversity in the rhizosphere of medicinal plants and assessed their antimicrobial properties.
A tripartite bacterial-fungal-plant symbiosis in the mycorrhiza-shaped microbiome drives plant growth and mycorrhization
C. F. ZHANG
, M. G. A. VAN DER HEIJDEN, B. K. DODDS, T. B. NGUYEN, J. SPOOREN, A. VALZANO-HELD, M. COSME, R. L. BERENDSEN
Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
Plant microbiomes play crucial roles in nutrient cycling and plant growth, and are shaped by a complex interplay between plants, microbes, and the environment. The role of bacteria as mediators of the 400-million-year-old partnership between the majority of land plants and, arbuscular mycorrhizal (AM) fungi is still poorly understood. Here we test whether AM hyphae-associated bacteria influence the success of the AM symbiosis. Using partitioned microcosms containing field soil, we discovered that AM hyphae and roots selectively assemble their own microbiome from the surrounding soil. In two independent experiments, we identified several bacterial genera, including Devosia, that are consistently enriched on AM hyphae. Subsequently, we isolated 144 pure bacterial isolates from a mycorrhiza-rich sample of extraradical hyphae and isolated Devosia sp. ZB163 as root and hyphal colonizer. We show that this AM-associated bacterium synergistically acts with mycorrhiza on the plant root to strongly promote plant growth, nitrogen uptake, and mycorrhization. Our results highlight that AM fungi do not function in isolation and that the plant-mycorrhiza symbiont can recruit beneficial bacteria that support the symbiosis.