Wang Lei, Tang Zhanhui
School of Environment, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, China.
Front Plant Sci. 2022 Aug 22;13:975488. doi: 10.3389/fpls.2022.975488. eCollection 2022.
Arbuscular mycorrhizal (AM) symbiosis in soil may be directly or indirectly involved in the reproductive process of sexually reproducing plants (seed plants), and affect their reproductive fitness. However, it is not clear how underground AM symbiosis affects plant reproductive function. Here, we reviewed the studies on the effects of AM symbiosis on plant reproductive fitness including both male function (pollen) and female function (seed). AM symbiosis regulates the development and function of plant sexual organs by affecting the nutrient using strategy and participating in the formation of hormone networks and secondary compounds in host plants. The nutrient supply (especially phosphorus supply) of AM symbiosis may be the main factor affecting plant's reproductive function. Moreover, the changes in hormone levels and secondary metabolite content induced by AM symbiosis can also affect host plants reproductive fitness. These effects can occur in pollen formation and transport, pollen tube growth and seed production, and seedling performance. Finally, we discuss other possible effects of AM symbiosis on the male and female functional fitness, and suggest several additional factors that may be involved in the influence of AM symbiosis on the reproductive fitness of host plants. We believe that it is necessary to accurately identify and verify the mechanisms driving the changes of reproductive fitness of host plant in symbiotic networks in the future. A more thorough understanding of the mechanism of AM symbiosis on reproductive function will help to improve our understanding of AM fungus ecological roles and may provide references for improving the productivity of natural and agricultural ecosystems.
土壤中的丛枝菌根（AM）共生可能直接或间接参与有性繁殖植物（种子植物）的繁殖过程，并影响其繁殖适合度。然而，尚不清楚地下AM共生如何影响植物的繁殖功能。在此，我们综述了关于AM共生对植物繁殖适合度影响的研究，包括雄性功能（花粉）和雌性功能（种子）。AM共生通过影响养分利用策略以及参与宿主植物激素网络和次生化合物的形成来调节植物性器官的发育和功能。AM共生的养分供应（尤其是磷供应）可能是影响植物繁殖功能的主要因素。此外，AM共生诱导的激素水平和次生代谢物含量的变化也会影响宿主植物的繁殖适合度。这些影响可发生在花粉形成与运输、花粉管生长以及种子生产和幼苗表现等过程中。最后，我们讨论了AM共生对雄性和雌性功能适合度的其他可能影响，并提出了几个可能参与AM共生对宿主植物繁殖适合度影响的额外因素。我们认为，未来有必要准确识别和验证共生网络中驱动宿主植物繁殖适合度变化的机制。更深入地了解AM共生对繁殖功能的机制将有助于增进我们对AM真菌生态作用的理解，并可能为提高自然和农业生态系统的生产力提供参考。
