University of Toronto Scarborough, Toronto, Ontario, Canada.
University of Toronto Scarborough, Toronto, Ontario, Canada
Appl Environ Microbiol. 2019 Sep 17;85(19). doi: 10.1128/AEM.00383-19. Print 2019 Oct 1.
A collection of bacterial endophytes isolated from stem tissues of plants growing in soils highly contaminated with petroleum hydrocarbons were screened for plant growth-promoting capabilities. Twenty-seven endophytic isolates significantly improved the growth of plants in comparison to that of uninoculated control plants. The five most beneficial isolates, one strain each of , , and and two strains of were further examined for growth promotion in , lettuce, basil, and bok choy plants. Host-specific plant growth promotion was observed when plants were inoculated with the five bacterial strains. strain M251 increased the total biomass and total root length of plants by 4.7 and 5.8 times, respectively, over that of control plants and improved lettuce and basil root growth, while strain M259 promoted shoot and root growth, lettuce and basil root growth, and bok choy shoot growth. A genome comparison between strains M251 and M259 showed that both genomes contain up to 70 actinobacterial putative plant-associated genes and genes involved in known plant-beneficial pathways, such as those for auxin and cytokinin biosynthesis and 1-aminocyclopropane-1-carboxylate deaminase production. This study provides evidence of direct plant growth promotion by The discovery of new plant growth-promoting bacteria is necessary for the continued development of biofertilizers, which are environmentally friendly and cost-efficient alternatives to conventional chemical fertilizers. Biofertilizer effects on plant growth can be inconsistent due to the complexity of plant-microbe interactions, as the same bacteria can be beneficial to the growth of some plant species and neutral or detrimental to others. We examined a set of bacterial endophytes isolated from plants growing in a unique petroleum-contaminated environment to discover plant growth-promoting bacteria. We show that strains of exhibit strain-specific plant growth-promoting effects on four different plant species.
从生长在高石油烃污染土壤中的植物茎组织中分离出的一批细菌内生菌被筛选出具有促进植物生长的能力。与未接种对照植物相比，27 个内生菌分离株显著促进了植物的生长。最有益的五个内生菌分离株，每个种各一株，和 和两株 ，进一步研究了它们在 、生菜、罗勒和白菜植物中的生长促进作用。当用这五种细菌菌株接种植物时，观察到了宿主特异性的植物生长促进作用。 菌株 M251 使 植物的总生物量和总根长分别比对照植物增加了 4.7 倍和 5.8 倍，并改善了生菜和罗勒的根生长，而 菌株 M259 促进了 的茎和根生长、生菜和罗勒的根生长以及白菜的茎生长。 菌株 M251 和 M259 之间的基因组比较表明，两个基因组都包含多达 70 个放线菌假定的植物相关基因和参与已知植物有益途径的基因，如生长素和细胞分裂素生物合成和 1-氨基环丙烷-1-羧酸脱氨酶生产。本研究提供了 直接促进植物生长的证据。发现新的植物促生细菌对于生物肥料的持续发展是必要的，生物肥料是对传统化肥具有环境友好和成本效益的替代品。由于植物-微生物相互作用的复杂性，生物肥料对植物生长的影响可能不一致，因为相同的细菌可能对一些植物物种的生长有益，而对其他物种则是中性或有害的。我们检查了一组从生长在独特的石油污染环境中的植物中分离出的细菌内生菌，以发现具有促进植物生长的细菌。我们表明， 菌株表现出对四种不同植物物种的特定菌株的植物生长促进作用。
