Bacterial endophytes from seeds of conifers with potential role in biocontrol: microbiome analysis

Abstract: It is well established that many forest conifers depend on associations with mycorrhizal and foliar endophytic fungi. However, our understanding of the bacterial endophytes of conifers is limited. In this work we used 16S rRNA pyrosequencing to ask whether these conifers host a core of bacterial species that are consistently associated with conifer individuals and therefore potential mutualists. It was found that for seeds of coniferous the total number of established nucleotide sequences belonging to bacteria is low and for different samples does not exceed 100. Overall, it should be noted that at the level of phyla the dominating position was taken by representatives of the Proteobacteria (about 30-35% of the total) and Actinobacteria (30%), whereas the number of such phyla as Firmicutes, Bacteroidetes, Acidobacteria was significantly lower (1 to 5%). The most interesting results of the microbiome analysis of the seeds of conifers can be monitored at the level of families. For seeds it was found that diversity of endophytic bacteria in the composition of microbiome is low and is determined by four main families: Enterobacteriaceae, Pseudomonadaceae, Oxalobacteraceae and Comamonadaceae. As a general trend, similarity is found with other microbiomes of conifers seeds with the same dominant components that are characteristic for pine and spruce seeds.