韦革宏、焦硕等《Microbiome》2023年

论文题目：Metagenomics insights into responses of rhizobacteria and their alleviation role in licorice allelopathy

论文作者：Yang Liu，Hao Wang，Xun Qian，Jie Gu，Weimin Chen，Xihui Shen，Shiheng Tao，Shuo Jiao，Gehong Wei

论文摘要：

Background

Allelopathy is closely associated with rhizosphere biological processes, and rhizosphere microbial communities are essential for plant development. However, our understanding of rhizobacterial communities under influence of allelochemicals in licorice remains limited. In the present study, the responses and effects of rhizobacterial communities on licorice allelopathy were investigated using a combination of multi-omics sequencing and pot experiments, under allelochemical addition and rhizobacterial inoculation treatments.

Results

Here, we demonstrated that exogenous glycyrrhizin inhibits licorice development, and reshapes and enriches specific rhizobacteria and corresponding functions related to glycyrrhizin degradation. Moreover, theNovosphingobiumgenus accounted for a relatively high proportion of the enriched taxa and appeared in metagenomic assembly genomes. We further characterized the different capacities of single and synthetic inoculants to degrade glycyrrhizin and elucidated their distinct potency for alleviating licorice allelopathy. Notably, the single replenished N (Novosphingobium resinovorum) inoculant had the greatest allelopathy alleviation effects in licorice seedlings.

Conclusions

Altogether, the findings highlight that exogenous glycyrrhizin simulates the allelopathic autotoxicity effects of licorice, and indigenous single rhizobacteria had greater effects than synthetic inoculants in protecting licorice growth from allelopathy. The results of the present study enhance our understanding of rhizobacterial community dynamics during licorice allelopathy, with potential implications for resolving continuous cropping obstacle in medicinal plant agriculture using rhizobacterial biofertilizers.

背景

化感作用与根际生物过程密切相关，根际微生物群落对植物发育至关重要。然而，我们对甘草中化感物质影响下的根际细菌群落的了解仍然有限。本研究采用多组学测序和盆栽试验相结合的方法，在化感化学添加和根际细菌接种处理下，研究了根际细菌群落对甘草化感作用的响应和影响。

结果

我们证明了外源的甘草酸抑制了甘草的发育，重塑和丰富了与甘草酸降解相关的特定根际细菌。此外，Novosphingobium属在富集类群中所占比例较高，出现在宏基因组组装基因组中。我们进一步表征了单一和合成接种剂降解甘草酸的不同能力，并阐明了它们减轻甘草化感作用的不同效力。其中，加入Novosphingobium resinovorum接种剂对甘草幼苗化感作用的缓解效果最大。

结论

综上所述，外源甘草酸模拟了甘草的化感自毒作用，而本土单一根细菌在保护甘草生长免受化感影响的作用比合成接种剂更大。本研究结果增强了我们对甘草化感作用过程中根际细群落动态的认识，对利用微生物肥料解决药用植物连作障碍具有潜在的指导意义。

论文链接：https://doi.org/10.1186/s40168-023-01511-3