Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.
State Key Laboratory of Plant Physiology and Biochemistry, Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, China.
Nat Commun. 2021 May 28;12(1):3209. doi: 10.1038/s41467-021-23553-7.
Recent studies have demonstrated that drought leads to dramatic, highly conserved shifts in the root microbiome. At present, the molecular mechanisms underlying these responses remain largely uncharacterized. Here we employ genome-resolved metagenomics and comparative genomics to demonstrate that carbohydrate and secondary metabolite transport functionalities are overrepresented within drought-enriched taxa. These data also reveal that bacterial iron transport and metabolism functionality is highly correlated with drought enrichment. Using time-series root RNA-Seq data, we demonstrate that iron homeostasis within the root is impacted by drought stress, and that loss of a plant phytosiderophore iron transporter impacts microbial community composition, leading to significant increases in the drought-enriched lineage, Actinobacteria. Finally, we show that exogenous application of iron disrupts the drought-induced enrichment of Actinobacteria, as well as their improvement in host phenotype during drought stress. Collectively, our findings implicate iron metabolism in the root microbiome's response to drought and may inform efforts to improve plant drought tolerance to increase food security.
最近的研究表明，干旱会导致根系微生物组发生显著的、高度保守的变化。目前，这些反应的分子机制在很大程度上仍未被阐明。在这里，我们采用基因组解析宏基因组学和比较基因组学来证明，碳水化合物和次生代谢物运输功能在耐旱丰富的类群中过度表达。这些数据还表明，细菌铁运输和代谢功能与干旱富集高度相关。使用时间序列根 RNA-Seq 数据，我们证明了干旱胁迫会影响根内的铁稳态，并且植物植物铁载体的缺失会影响微生物群落组成，导致耐旱丰富的放线菌谱系显著增加。最后，我们表明，外源铁的应用会破坏干旱诱导的放线菌富集，以及它们在干旱胁迫期间对宿主表型的改善。总的来说，我们的研究结果表明，铁代谢参与了根系微生物组对干旱的反应，这可能为提高植物耐旱性以增加粮食安全提供信息。
