Abstract:Seed, the specific reproductive organ of spermatophyte, is recognized as a potent reservoir and vector for beneficial and pathogenic microorganisms which play important roles in the growth, development, health, quality, and yield of plants. Plant microbiome, especially rhizosphere microbiome and phyllosphere microbiome, has attracted wide attention and flourished with the development of microbial ecology and related technology. However, seed microbiome is still a virgin field absent from enough concern. Bacteria are well known as the dominant microorganisms in seed endophytes. In this review we summarized the progress in the composition, biological function, transmission, and core microbiome of seed bacteriome. We further expounded the definition and significance of core microbiome in seed endophytes and proposed the questions to be solved, aiming to provide guidance for the future research in the leading-edge area.