Garneau Louis, Beauregard Pascale B, Roy Sébastien
Centre SÈVE, Département de biologie, Faculté des Sciences, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke, Québec, Canada, J1K 2R1.
Can J Microbiol. 2023 Feb 1;69(2):72-87. doi: 10.1139/cjm-2022-0073. Epub 2022 Oct 26.
Endophytic bacterial populations are well-positioned to provide benefits to their host plants such as nutrient acquisition and plant hormone level manipulation. Actinorhizal plants such as alders are well known for their microbial symbioses that allow them to colonize harsh environments whether natural or anthropized. Although the nitrogen-fixing actinobacterium sp. is the main endophyte found in alder root nodules, other bacterial genera, whose roles remain poorly defined, inhabit this niche. In this study, we isolated a diverse panel of non- nodular endophytes (NFNE). Some NFNE were isolated from alders grown from surface-sterilized seeds and maintained in sterile conditions, suggesting these may have been seed-borne. In vitro testing of 24 NFNE revealed some possessed putative plant growth promotion traits. Their genomes were also sequenced to identify genes related to plant growth promotion traits. This study highlights the complexity of the alder nodular microbial community. It paves the way for further understanding of the biology of nodules and could help improve land reclamation practices that involve alders.
内生细菌群体处于良好位置，能够为其宿主植物带来诸多益处，如获取养分和调控植物激素水平。像桤木这样的放线菌根植物以其微生物共生关系而闻名，这种共生关系使它们能够在自然或人为的恶劣环境中定殖。尽管固氮放线菌是在桤木根瘤中发现的主要内生菌，但其他细菌属也存在于这个生态位，其作用仍不太明确。在本研究中，我们分离出了一组多样的非根瘤内生菌（NFNE）。一些NFNE是从经表面消毒的种子培育并在无菌条件下培养的桤木中分离出来的，这表明它们可能是种子携带的。对24株NFNE的体外测试表明，其中一些具有推定的促进植物生长的特性。还对它们的基因组进行了测序，以鉴定与促进植物生长特性相关的基因。这项研究突出了桤木根瘤微生物群落的复杂性。它为进一步了解根瘤生物学铺平了道路，并有助于改善涉及桤木的土地复垦实践。
