Diversity of seed endophytic bacterial and fungal communities of eight alpine meadow grassland species

Plant seeds are involved in the transmission of microorganisms from one plant generation to the next, acting as initial inoculums for the plant microbiomes of a wide range of species. It has been well established that seed-borne microbes can establish themselves in various plant parts and provide a range of benefits to their host plants. Previous studies have characterized the seed microbiomes of several agricultural crops, but the seed microbiomes of grassland species are still poorly defined. The aim of this study was to characterize the seed microbiomes of eight grassland species that are dominant among the alpine meadow grasslands of the Qinghai Tibetan Plateau (QTP) using Illumina MiSeq DNA sequencing. The results showed a diverse consortia of bacteria and fungi (115 bacterial genera and 135 fungal genera) that thrive inside the seeds of eight grassland species. The bacterial and fungal communities inside the seeds were significantly different among the eight grassland species. The dominant seed bacterial and fungal phyla of the eight grassland species were Proteobacteria and Ascomycota, respectively. The bacterial genera Pseudomonas, Pantoea, and Ochrobactrum, and the fungal genera Botrytis, Bullera, and Didymella were found in the seeds of all eight grassland species. There were also bacterial and fungal genera unique to each of the seeds of the eight grassland species. This study showed that plant identity is an important factor shaping the seed microbiome. Some of the microbes identified in this study have been previously identified as being beneficial to their host plants, hence the results of this study can be used for future studies on seed microbiome manipulations to ensure healthy and productive grasslands.