Selenium and the Plant Microbiome

Studies of plant microbiomes, which include all microorganisms that occur on and inside plants, are increasingly popular in multiple fields, particularly due to advances in next generation sequencing, a technique that has advantages over traditional culture-based methods. There are many advances yet to be made with regard to the interaction of selenium (Se) and the plant microbiome. This chapter will discuss aspects of the plant microbiome as well as the discoveries to date with regard to plant-associated microbes and Se, mostly explored through culture-dependent methods. Selenium hyperaccumulators appear to harbor equally diverse microbial communities as non-hyperaccumulators, although the microbial composition may vary. Investigations have isolated a variety of microbes from plants or soil in seleniferous areas including bacteria and fungi with enhanced Se tolerance. Inoculation of plants with individual strains or consortia of microbes was able to promote plant growth, Se uptake and/or Se volatilization, which shows promise for applications in phytoremediation or biofortification. Plant-derived microbes may also be applicable for cleanup of Se from wastewaters.