PDF(Pubmed)
Abstract：
Seed endophytic microbiomes are shaped by host and environmental factors and play a crucial role in their host growth and health. Studies have demonstrated that host genotype, including hybridization, affects seed microbiomes. Heterosis features are also observed in root-associated microbiomes. It remains unclear, however, whether heterosis exists in seed endophytic microbiomes and whether hybrid microbiota provide noticeable advantages to host plant growth, especially to seed germination. Here, we investigated the structure of seed endophytic bacterial and fungal communities from three hybrid rice varieties and their respective parents using amplicon sequencing targeting 16S rRNA and ITS2 genes. Heterosis was found in diversity and composition of seed endophytic microbiomes in hybrids, which hosted more diverse communities and significantly higher abundances of plant growth-promoting taxa, such as Pseudomonas and Rhizobium genera compared with their parental lines. Co-occurrence network analysis revealed that there are potentially tighter microbial interactions in the hybrid seeds compared with their parent seeds. Finally, inoculation of seed-cultivable endophytes, isolated from hybrids, resulted in a greater promotion of seed germination compared with those isolated from parent lines. These findings suggest that heterosis exists not only in plant traits but also in seed endophytic microbiota, the latter in turn promotes seed germination, which offers valuable guidance for microbiome-assisted rice breeding.IMPORTANCEGenetic and physiological changes associated with plant hybridization have been studied for many crop species. Still, little is known about the impact of hybridization on the seed microbiota. In this study, we indicate that hybridization has a significant impact on the endophytic bacterial and fungal communities in rice seeds. The seed endophytic microbiomes of hybrids displayed distinct characteristics from those of their parental lines and exhibited potential heterosis features. Furthermore, the inoculation of seed-cultivable endophytes isolated from hybrids exhibited a greater promotion effect on seed germination compared with those isolated from the parents. Our findings make a valuable contribution to the emerging field of microbiome-assisted plant breeding, highlighting the potential for a targeted approach that aims to achieve not only desired plant traits but also plant-beneficial microbial communities on the seeds.
摘要：
种子内生微生物群受宿主和环境因素的影响，对宿主的生长和健康起着至关重要的作用。研究表明，宿主基因型，包括杂交,影响种子微生物组。在根相关微生物组中也观察到杂种优势特征。目前还不清楚,然而,种子内生微生物群是否存在杂种优势，杂种微生物群是否为寄主植物生长提供显著优势，特别是种子发芽。这里,我们使用针对16SrRNA和ITS2基因的扩增子测序研究了来自三个杂交水稻品种及其各自亲本的种子内生细菌和真菌群落的结构。杂种优势在于杂种中种子内生微生物的多样性和组成，拥有更多样化的社区和更丰富的植物生长促进分类群，如假单胞菌属和根瘤菌属与其亲本系相比。共现网络分析显示，与亲本种子相比，杂种种子中可能存在更紧密的微生物相互作用。最后,种子可培养内生菌的接种，从杂种中分离出来，与从亲本系分离的种子相比，种子发芽的促进作用更大。这些发现表明，杂种优势不仅存在于植物性状中，而且还存在于种子内生菌群中。后者反过来促进种子发芽，这为微生物组辅助水稻育种提供了有价值的指导。重要性已经对许多作物物种研究了与植物杂交相关的遗传和生理变化。尽管如此，关于杂交对种子微生物群的影响知之甚少。在这项研究中,我们表明，杂交对水稻种子中的内生细菌和真菌群落有显著影响。杂种的种子内生微生物群表现出与其亲本系不同的特征，并表现出潜在的杂种优势。此外，与从亲本中分离的内生菌相比，从杂种中分离的种子可培养内生菌的接种对种子萌发的促进作用更大。我们的发现为微生物组辅助植物育种的新兴领域做出了有价值的贡献，强调了有针对性的方法的潜力，该方法不仅旨在实现所需的植物性状，还旨在实现种子上对植物有益的微生物群落。
