论文题目：Seed microbiomes promote Astragalus mongholicus seed germination through pathogen suppression and cellulose degradation
论文作者：Da Li, Weimin Chen*, Wen Luo, Haofei Zhang, Yang Liu, Duntao Shu*, Gehong Wei*
论文摘要：
Background：Seed-associated microorganisms play crucial roles in maintaining plant health by providing nutrients and resistance to biotic and abiotic stresses. However, their functions in seed germination and disease resistance remain poorly understood. In this study, we investigated the microbial community assembly features and functional profiles of the spermosphere and endosphere microbiomes related to germinated and ungerminated seeds of Astragalus mongholicus by using amplicon and shotgun metagenome sequencing techniques. Additionally, we aimed to elucidate the relationship between beneficial microorganisms and seed germination through both in vitro and in vivo pot experiments.
Results：Our findings revealed that germination significantly enhances the diversity of microbial communities associated with seeds. This increase in diversity is driven through environmental ecological niche differentiation, leading to the enrichment of potentially beneficial probiotic bacteria such as Pseudomonas and Pantoea. Conversely, Fusarium was consistently enriched in ungerminated seeds. The co-occurrence network patterns revealed that the microbial communities within germinated and ungerminated seeds presented distinct structures. Notably, germinated seeds exhibit more complex and interconnected networks, particularly for bacterial communities and their interactions with fungi. Metagenome analysis showed that germinated seed spermosphere soil had more functions related to pathogen inhibition and cellulose degradation. Through a combination of culture-dependent and germination experiments, we identified Fusarium solani as the pathogen. Consistent with the metagenome analysis, germination experiments further demonstrated that bacteria associated with pathogen inhibition and cellulose degradation could promote seed germination and vigor. Specifically, Paenibacillus sp. significantly enhanced A. mongholicus seed germination and plant growth.
Conclusions：Our study revealed the dynamics of seed-associated microorganisms during seed germination and confirmed their ecological role in promoting A. mongholicus seed germination by suppressing pathogens and degrading cellulose. This study offers a mechanistic understanding of how seed microorganisms facilitate successful seed germination, highlighting the potential for leveraging these microbial communities to increase plant health.
种子相关的微生物在维持植物健康方面发挥着至关重要的作用，它们提供营养并帮助植物抵抗生物和非生物胁迫。然而，它们在种子萌发和抗病性中的功能尚不清楚。本项研究采用扩增子和宏基因组测序技术，研究了与发芽和未发芽种子相关的Astragalus mongholicus的种子内生和种子际微生物组的构建和功能特征。此外，通过体外和体内盆栽实验阐明有益微生物与种子萌发之间的关系。结果表明：种子萌发显著增强了与种子相关的微生物群落的多样性，这种多样性的增加是通过种子相关生态位分化驱动的，导致潜在有益的益生菌如假单胞菌（Pseudomonas）和泛菌（Pantoea）的富集；相反，镰刀菌（Fusarium）在未发芽的种子中持续富集。共现网络模式显示，发芽和未发芽种子内的微生物群落呈现出不同的结构；发芽的种子表现出更复杂和相互连接的网络，特别是细菌群落及其与真菌的相互作用；宏基因组分析表明，发芽种子际土壤具有更多与病原体抑制和纤维素降解相关的功能。；通过结合依赖培养和萌发实验，确定了镰刀菌（Fusarium solani）为病原体。与宏基因组分析一致，萌发实验进一步证明，与病原体抑制和纤维素降解相关的细菌可以促进种子萌发和活力。特别是，Paenibacillus sp.显著增强了A. mongholicus的种子萌发和植物生长。本研究揭示了种子萌发期间种子相关微生物的动态变化，并证实了它们在通过抑制病原体和降解纤维素来促进A. mongholicus种子萌发方面的生态作用。这项研究提供了对种子微生物如何促进成功种子萌发的机制理解，突出了利用这些微生物群落增加植物健康的潜力。
论文链接：https://doi.org/10.1186/s40168-024-02014-5