Abstract
This study was conducted to explore effects of the systemic fungal endophyte Epichloë gansuensis on root and rhizosphere soil bacterial diversity of Achnatherum inebrians host plants growing under different moisture conditions. Soil properties of different treatments were compared using standard techniques. A total of 4371379 16S rRNA gene sequences were obtained and assigned to 5025 operational taxonomic units (OTUs). These OTUs in roots and rhizosphere soil were divided into 13 and 17 phyla, respectively, and the Actinobacteria and Proteobacteria were the most abundant phyla both in roots and rhizosphere soil. Shannon diversity and Chao1 richness index of bacteria in rhizosphere soil was significantly higher than in roots. E. gansuensis decreased the Shannon diversity of the root-associated bacterial community, and increased Shannon diversity and Chao1 richness index of the rhizosphere soil bacterial community of A. inebrians. Meanwhile, Chao1 richness of the rhizosphere soil bacterial community of A. inebrians significantly increased with the increase of the soil moisture level. Structural equation modeling also emphasized that E. gansuensis decreased the diversity of the root-associated bacterial community and increased the diversity of the rhizosphere soil bacterial community through decreasing soil available N. Additionally, soil moisture increased the diversity of the rhizosphere soil bacterial community through increased soil pH, C/N, and NN, and decreased soil AP. The E. gansuensis endophyte and soil moisture effects on root and rhizosphere soil bacterial diversity were likely to be from responses to modifications of the rhizosphere soil properties.
Highlights
Microbial associations are widely distributed in terrestrial ecosystems, and plant tissues are associated with a wide range of microbes, including fungi (Johnson et al, 2013), and bacteria (BellDereske et al, 2017)
In 2013, seeds of E. gansuensis-free (EF) and E. gansuensis-infected (EI) A. inebrians plants were collected, the endophyte-infection status was confirmed in the laboratory, and the seeds were stored at 4◦C in a refrigerator
Our study that examined the influence of the presence of a mutualistic seed-borne, systemic fungal endophyte and the effects of different available soil moisture on bacterial communities revealed that E. gansuensis influenced the diversity and richness of the bacterial community in the roots and rhizosphere soil of A. inebrians plants, and soil moisture only affected the diversity and richness of the bacterial community of A. inebrians plants rhizosphere soil
Summary
Microbial associations are widely distributed in terrestrial ecosystems, and plant tissues are associated with a wide range of microbes, including fungi (Johnson et al, 2013), and bacteria (BellDereske et al, 2017). Interaction Between Plant and Microbe grasses and the genus Epichloë are generally considered to be mutualistic and the transmission of many species is completely vertical (Schardl et al, 2004; Christensen et al, 2008) Previous studies on these symbiotic relationships have focused on the genera Lolium and Festuca because they enhance the adaptability and productivity of host plants under abiotic and biotic stresses (Johnson et al, 2013; Soto-Barajas et al, 2016). Another grass species that is host to an Epichloë endophyte and which has become the focus for intense research is Achnatherum inebrians. The deterrence of grazing and the enhanced tolerance to abiotic and biotic stresses conferred by the presence of an Epichloë endophyte have led to the greatly increased distribution of A. inebrians throughout the grasslands of northwest China that have been degraded by overgrazing (Zhao et al, 2005; Yao et al, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
