Department of Ecological Science and Engineering, College of Resources and Environmental Sciences, China Agricultural University, Beijing, P. R. China.
Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, P. R. China.
J Basic Microbiol. 2019 Apr;59(4):402-411. doi: 10.1002/jobm.201800510. Epub 2019 Jan 15.
Rahnella aquatilis HX2 was isolated from Beijing vineyard soil and used as a plant growth-promoting rhizobacterium in the field. Previous studies have shown that it has a broad in vitro antimicrobial spectrum and could inhibit a variety of plant pathogenic bacteria and fungi. In this study, a gene, acdS, encoding 1-aminocyclopropane-1-carboxylic acid-deaminase was disrupted by in-frame deletion in the HX2 strain. Compared to the wild-type, the acdS-mutant had higher rates of nitrogen fixation, reduced indole-3-acetic acid production, lowered efficacy as a biological control agent against the grape crown gall pathogen Agrobacterium vitis. Under saline stress conditions, plant height, above-ground fresh weight, root fresh weight of corn plants were increased by treatment with HX2 but this increase was compromised by the disruption of acdS gene. Our data confirmed the function of HX2 on plant growth promoting and demonstrated that acdS gene plays a major role in its PGPR activities.
海洋希瓦氏菌 HX2 从北京葡萄园土壤中分离出来，并在田间用作植物促生根际细菌。先前的研究表明，它具有广泛的体外抗菌谱，能够抑制多种植物病原菌和真菌。在这项研究中，通过在 HX2 菌株中进行框内缺失，破坏了编码 1-氨基环丙烷-1-羧酸脱氨酶的 acdS 基因。与野生型相比，acdS 突变体具有更高的固氮率，降低了吲哚-3-乙酸的产生，降低了其作为生物防治剂防治葡萄冠瘿病病原体根癌农杆菌的功效。在盐胁迫条件下，用 HX2 处理可增加玉米植株的株高、地上鲜重和根鲜重，但 acdS 基因的破坏削弱了这一作用。我们的数据证实了 HX2 对植物生长促进的作用，并表明 acdS 基因在其 PGPR 活性中起主要作用。
