Ruotsalainen Anna L, Kauppinen Miia, Wäli Piippa R, Saikkonen Kari, Helander Marjo, Tuomi Juha
Department of Ecology and Genetics, POB 3000, University of Oulu, FI-90014 Oulu, Finland.
Biodiversity Unit, University of Turku, FI-20014 Turku, Finland.
Trends Plant Sci. 2022 Mar;27(3):247-254. doi: 10.1016/j.tplants.2021.10.001. Epub 2021 Oct 27.
Plant roots are abundantly colonized by dark septate endophytic (DSE) fungi in virtually all ecosystems. DSE fungi are functionally heterogeneous and their relationships with plants range from antagonistic to mutualistic. Here, we consider the role of by-product benefits in DSE and other root-fungal symbioses. We compared host investments against symbiont-derived benefits for the host plant and categorized these benefits as by-products or benefits requiring reciprocal investment from the host. By-product benefits may provide the variability required for the evolution of invested mutualisms between the host and symbiont. We suggest that DSE could be considered as 'a by-product mutualist transitional phase' in the evolution of cooperative mycorrhizal symbionts from saprotrophic fungi.
在几乎所有生态系统中，植物根系都大量被深色有隔内生菌（DSE）真菌定殖。DSE真菌在功能上具有异质性，它们与植物的关系从拮抗到互利共生不等。在这里，我们探讨了副产物益处在DSE以及其他根际真菌共生关系中的作用。我们比较了宿主植物针对共生体衍生益处的投入，并将这些益处归类为副产物或需要宿主进行对等投入的益处。副产物益处可能为宿主与共生体之间投入型互利共生关系的进化提供所需的变异性。我们认为，在腐生真菌向合作性菌根共生体的进化过程中，DSE可被视为“副产物互利共生过渡阶段”。
