title: The interactions of bacteria with fungi in soil: emerging concepts.
abstract: In this chapter, we review the existing literature on bacterial-fungal interactions in soil, exploring the role fungi may play for soil bacteria as providers of hospitable niches. A focus is placed on the mycosphere, i.e., the narrow zone of influence of fungal hyphae on the external soil milieu, in which hypha-associated bacterial cells dwell. Evidence is brought forward for the contention that the hyphae of both mycorrhizal and saprotrophic fungi serve as providers of ecological opportunities in a grossly carbon-limited soil, as a result of their release of carbonaceous compounds next to the provision of a colonizable surface. Soil bacteria of particular nature are postulated to have adapted to such selection pressures, evolving to the extent that they acquired capabilities that allow them to thrive in the novel habitat created by the emerging fungal hyphae. The mechanisms involved in the interactions and the modes of genetic adaptation of the mycosphere dwellers are discussed, with an emphasis on one key mycosphere-adapted bacterium, Burkholderia terrae BS001. In this discussion, we interrogate the positive interactions between soil fungi and bacteria, and refrain from considering negative interactions.
authors.affiliation: Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands.
authors.forename: Irshad Ul
authors.initials: IU
authors.lastname: Haq
authors.affiliation: Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands.
authors.forename: Miaozhi
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands.
authors.forename: Pu
authors.initials: P
authors.lastname: Yang
authors.affiliation: Department of Microbial Ecology, Center for Ecological and Evolutionary Studies (CEES), University of Groningen, Groningen, The Netherlands. Electronic address: j.d.van.elsas@rug.nl.
authors.forename: Jan Dirk
authors.initials: JD
authors.lastname: van Elsas
mesh_terms: D001419:Bacteria / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D017753:Ecosystem; D005658:Fungi / Q000235:genetics / Q000502:physiology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D012987:Soil
keywords: Bacterial–fungal interactions; Horizontal gene transfer; Mycorrhizosphere; Mycosphere; Plasmids; Soil