Yang Zhen-Hui, Xing Ying, Ma Jian-Guo, Li Yu-Man, Yang Xiao-Qian, Wang Xiao-Bo
State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China.
Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
J Fungi (Basel). 2022 Feb 27;8(3):237. doi: 10.3390/jof8030237.
Fungal endophytes have been extensively found in most terrestrial plants. This type of plant-microorganism symbiosis generates many benefits for plant growth by promoting nutrient availability, uptake, and resistance to environmental disease or stress. Recent studies have reported that fungal endophytes have a potential impact on plant litter decomposition, but the mechanisms behind its effect are not well understood. We proposed a hypothesis that the impacts of fungal endophytes on litter decomposition are not only due to a shift in the symbiont-induced litter quality but a shift in soil microenvironment. To test this hypothesis, we set-up a field trial by planting three locally dominant grass species (wild barley, drunken horse grass, and perennial ryegrass) with endophyte-infected (E) and -free (E) status, respectively. The aboveground litter and bulk soil from each plant species were collected. The litter quality and the soil biotic and abiotic parameters were analyzed to identify their changes across E and E status and plant species. While endophyte status mainly caused a significant shift in soil microenvironment, plant species had a dominant effect on litter quality. Available nitrogen (N) and phosphorus (P) as well as soil organic carbon and microbial biomass in most soils with planting E plants increased by 17.19%, 14.28%, 23.82%, and 11.54%, respectively, in comparison to soils with planting E plants. Our results confirm that fungal endophytes have more of an influence on the soil microenvironment than the aboveground litter quality, providing a partial explanation of the home-field advantage of litter decomposition.
真菌内生菌在大多数陆生植物中广泛存在。这种植物 - 微生物共生关系通过促进养分有效性、吸收以及对环境病害或胁迫的抗性，为植物生长带来诸多益处。最近的研究报道，真菌内生菌对植物凋落物分解有潜在影响，但其作用机制尚不清楚。我们提出一个假设，即真菌内生菌对凋落物分解的影响不仅归因于共生体诱导的凋落物质量变化，还归因于土壤微环境的变化。为验证这一假设，我们开展了一项田间试验，分别种植三种当地优势草种（野生大麦、醉马草和多年生黑麦草），设置内生菌感染（E）和未感染（E）两种状态。收集每种植物的地上凋落物和原状土。分析凋落物质量以及土壤生物和非生物参数，以确定它们在E和E状态以及植物物种间的变化。与种植E植物的土壤相比，种植E植物的大多数土壤中有效氮（N）、磷（P）以及土壤有机碳和微生物生物量分别增加了17.19%、14.28%、23.82%和11.54%。我们的结果证实，真菌内生菌对土壤微环境的影响大于对地上凋落物质量的影响，这为凋落物分解的主场优势提供了部分解释。
