Community structure and function of cultivable Endophytic Bacteria isolated from four Moss species in Qilian Mountain

Mosses inhabiting alpine regions play a vital role in maintaining the stability of their environments. Despite their possible importance, the cultivatable endophytes of mosses in alpine regions have not been widely examined. The community structure of cultivatable endophytes from four species of mosses, Thuidium cymbifolium, Cirriphyllum cirrosum, Tortella tortuosa and Tortula reflexa, was assessed using 16S rRNA sequencing. The plant growth-promoting traits of all isolates were evaluated by measuring nitrogen fixation, phosphate solubilization, plant hormone (indoleacetic acid) production, and antifungal activity. Overall, 36 endophyte strains of bacteria were isolated from the 4 species of mosses from the Qilian Mountains in the Qinghai-Tibet Plateau, and were found to belong to 4 phyla, 11 genera, and 20 species. The dominant phyla were Proteobacteria (63.9%). Of the isolates, 53% belonged to Pseudomonas. The cultured bacteria from the mosses differed in their growth-promoting traits. This is the first report on the diversity of culturable endophytic bacteria in mosses from high-altitude cold regions. These plant growth-promoting bacteria might have applications in agriculture or be of value in strategies for environmental protection in alpine regions.