A foliar Epichloë endophyte and soil moisture modified belowground arbuscular mycorrhizal fungal biodiversity associated with Achnatherum inebrians

Abstract

Fungal symbionts, present in above and in belowground tissues, such as that of Epichloe endophytes and arbuscular mycorrhizal (AM) fungi, respectively, can modify the responses of host plants to environmental changes. Individual grass plants of the subfamily Pooideae can be host to both a foliar Epichloe endophytic fungus and root-associated AM fungi. Understanding the multiple interactions among above- and belowground symbionts and their host is an important step in understanding terrestrial ecosystems. A field experiment was conducted to study the effects of E. gansusensis endophyte and soil moisture on the belowground AM fungal biodiversity associated with Achnatherum inebrians, through amplicon sequencing technology. Soil properties were compared among stands using standard techniques. Our results show that E. gansusensis increased root-associated AM fungal diversity under drought conditions, while decreasing diversity under the water addition treatment. Water addition and water stress treatments decreased the diversity and richness of the AM fungal community in rhizosphere soil compared to the normal treatment. The E. gansusensis altered the composition of the root-associated AM fungal community. Aboveground biomass was closely positively related to the abundance of Funneliformis in the root and the diversity of the rhizosphere soil AM fungal community was positively related to the soil total nitrogen and phosphorus. This study suggested that soil moisture regimes shifted the effects of E. gansuensis on the diversity of the root-associated AM fungal community from positive to negative; moreover, soil moisture and foliar E. gansusensis altered soil properties, thereby affecting belowground AM fungi.