Centre SÈVE, Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
Mol Plant Microbe Interact. 2019 Sep;32(9):1188-1195. doi: 10.1094/MPMI-10-18-0278-R. Epub 2019 Jul 29.
is a Gram-positive plant-growth-promoting rhizobacterium exerting many beneficial effects on plant health. Because they secrete antimicrobial compounds and elicit induced systemic resistance, and phylogenetically related species are of particular interest as antifungals in organic agriculture. These bacteria are also known for their capacity to differentiate phenotypically into endospores able to withstand many environmental stresses. However, although is often inoculated on plants as spores, dynamics of germination and sporulation on roots remain unexplored. Using a hydroponic culture system and a soil system for we observed that spores germinate rapidly on contact with plants. However, the vegetative cells are abundant on roots for only a few days before reversing back to spores. We observed that the germinant receptor GerK and sporulation kinases KinA and KinB identified in vitro control sporulation dynamics on plants. Surprisingly, when plants are inoculated with free-living cells sporulate more rapidly than plant-associated cells. However, direct contact between plant and bacteria is required for the induction of sporulation in the surrounding . This study has fundamental implications for our understanding of interactions between spp. and plants, and particularly for a more efficient usage of as a biofertilizer or biofungicide.
是一种革兰氏阳性植物促生根际细菌，对植物健康有许多有益的影响。由于它们分泌抗菌化合物并引发诱导的系统抗性，因此与亲缘关系密切的物种作为有机农业中的抗真菌剂特别受到关注。这些细菌还因其能够表型分化为能够耐受许多环境压力的内生孢子而闻名。然而，尽管通常将 作为孢子接种在植物上，但根上的萌发和孢子形成动力学仍未得到探索。使用水培培养系统和土壤系统，我们观察到 孢子在接触植物时迅速萌发。然而，营养细胞在根上只存在几天，然后再返回到孢子。我们观察到在体外鉴定的萌发受体 GerK 和孢子形成激酶 KinA 和 KinB 控制着植物上的孢子形成动力学。令人惊讶的是，当植物用自由生活的细胞接种时，比植物相关的细胞更快地形成孢子。然而，周围 的孢子形成需要植物和细菌之间的直接接触。这项研究对我们理解 spp. 和植物之间的相互作用具有重要意义，特别是对更有效地将 用作生物肥料或生物杀菌剂具有重要意义。
