Zhang Cong, Yao Lu, Zhang Ming-Ming, Tian Dan-Dan, Wu Jing, Hu Yu-Zheng, Bao Kai, Ma Zeng-Xin, Tan Ling-Ling, Yang Song
School of Life Sciences, Qingdao Agricultural University, No.700 Changcheng Road, Chengyang District, Qingdao 266000, People's Republic of China.
Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, No.700 Changcheng Road, Chengyang District, Qingdao 266000, People's Republic of China.
J Appl Microbiol. 2025 Jan 6;136(1). doi: 10.1093/jambio/lxaf013.
The aim of this study was to evaluate the impact of the introduction of a phosphoribosylpyrophosphate synthetase (PRS) mutation into a plant growth-promoting strain of Methylorubrum on the enhancement of phyllosphere colonization, with the ultimate goal of improving plant growth and quality.
A strain of Methylorubrum populi (named HS04) was isolated from the groundnut leaves and found to process the plant-promoting traits, including the ability to produce indole acetic acid, siderophore, 1-aminocyclopropane-1-carboxylate deaminase, and to fix nitrogen. The application via foliar spray significantly increased the fresh weight of cucumber seedlings cultivated in a standard growth chamber, with 43.0% higher than the control group. Genomic analysis revealed that the presence of an array of genes involved in plant growth promotion, including accD, aldB, and ltaE, as well as potential nitrogen-fixation-related genes, including nifA, bchlLNB, and bchXYZ, in the HS04 strain. The introduction of the PRS mutation (an aspartic acid to an asparagine residue, D38N) in the HS04 strain (named HS04PTR) enhanced the utilization capacity of low concentrations of methanol and multi-carbon sources (C2-C5 carbon sources). The HS04PTR strain indicated a notable enhancement in the phyllosphere colonization, with the subsequent application further promoting the growth of cucumber seedlings. An agricultural solar greenhouse experiment was thus performed to assess the efficiency of the HS04PTR strain, sprayed at low abundance, in improving the growth and quality of cucumber plants, including vitamin C, reducing sugars, and total sugars.
Our findings provide insights into the potential of Methylorubrum/Methylobacterium strains with the PRS mutations as an efficient inoculant for advantageous agricultural applications.
本研究旨在评估将磷酸核糖焦磷酸合成酶（PRS）突变引入甲基红假单胞菌的植物促生菌株对增强叶际定殖的影响，最终目标是改善植物生长和品质。
从花生叶片中分离出一株甲基红假单胞菌（命名为HS04），发现其具有多种植物促生特性，包括产生吲哚乙酸、铁载体、1-氨基环丙烷-1-羧酸脱氨酶以及固氮能力。通过叶面喷施该菌株显著增加了在标准生长室中培养的黄瓜幼苗的鲜重，比对照组高43.0%。基因组分析表明，HS04菌株中存在一系列参与植物生长促进的基因，包括accD、aldB和ltaE，以及潜在的与固氮相关的基因，包括nifA、bchlLNB和bchXYZ。在HS04菌株（命名为HS04PTR）中引入PRS突变（天冬氨酸突变为天冬酰胺残基，D38N）提高了其对低浓度甲醇和多碳源（C2 - C5碳源）的利用能力。HS04PTR菌株在叶际定殖方面有显著增强，随后的应用进一步促进了黄瓜幼苗的生长。因此进行了一项农业日光温室试验，以评估低丰度喷施HS04PTR菌株对改善黄瓜植株生长和品质（包括维生素C、还原糖和总糖）的效率。
我们的研究结果为具有PRS突变的甲基红假单胞菌/甲基杆菌菌株作为高效接种剂在有利农业应用中的潜力提供了见解。
