Removal of Soil Microbes Alters Interspecific Competitiveness of Epichloë Endophyte-Infected over Endophyte-Free Leymus chinensis

Abstract

Epichloë endophytes may not only affect the growth and resistances of host grasses, but may also affect soil environment including soil microbes. Can Epichloë endophyte-mediated modification of soil microbes affect the competitive ability of host grasses? In this study, we tested whether Epichloë endophytes and soil microbes alter intraspecific competition between Epichloë endophyte-colonized (EI) and endophyte-free (EF) Leymus chinensis and interspecific competition between L. chinensis and Stipa krylovii. The results demonstrated that Epichloë endophyte colonization significantly enhanced the intraspecific competitive ability of L. chinensis and that this beneficial effect was not affected by soil microbes. Under interspecific competition, however, significant interactions between Epichloë endophytes and soil microbes were observed. The effect of Epichloë endophytes on interspecific competitiveness of the host changed from positive to neutral with soil microbe removal. Here higher mycorrhizal colonization rates probably contributed to interspecific competitive advantages of EI over EF L. chinensis. Our result suggests that Epichloë endophytes can influence the competitive ability of the host through plant soil feedbacks from the currently competing plant species.

The decreasing trend of the competitive advantage of endophyte-infected Achnatherum sibiricum over endophyte-free plants under high nitrogen conditions was reversed by pathogenic fungi inoculation

“…There is a symbiotic relationship between cool season grasses (subfamily Pooideae) and Epichloë (= Neotyphodium) fungal endophytes, and the tness of these endophytes and their host plants are tightly coupled (Clay and Schardl 2002). Endophyte infection can promote host plant growth (Chen et (Hill et al 1991(Hill et al ,1998Marks and Cheplick 1991), Festuca pratensis (Malinowski et al 1997), Bromus benekenii (Brem and Leuchtmann 2002) and Leymus chinensis (Liu et al 2020). However, a few studies have yielded inconsistent ndings.…”

Endophytic infection increases the belowground over-yielding effects of the host grass community mainly by increasing the complementary effects

“…At present, the reported research has focused on the interaction between AMF and Epichloë endophytes (Liu et al, 2017;Zhou et al, 2018). Some studies have found that the effects of endophytes on plant growth and competition are regulated by soil microbes (Liu et al, 2020a;Qu et al, 2023). Here, we selected the natural grass Achnatherum sibiricum as the experimental material.…”