Zhang Muchen, Wang Xiaoxuan, Ahmed Temoor, Liu Mengju, Wu Zhifeng, Luo Jinyan, Tian Ye, Jiang Hubiao, Wang Yanli, Sun Guochang, Li Bin
State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
Department of Plant Quarantine, Shanghai Extension and Service Center of Agriculture Technology, Shanghai 201103, China.
Pathogens. 2020 Sep 27;9(10):797. doi: 10.3390/pathogens9100797.
is the causative agent of rice sheath blight disease. In a previous study, we found that the growth of was inhibited by strain R456. Therefore, the present study was conducted to identify the genes involved in the antifungal activity of strain R456 by using a Tn5 transposon mutation method. Firstly, we constructed a random insertion transposon library of 997 mutants, out of which 11 mutants showed the defective antifungal activity against . Furthermore, the 10 antagonism-related genes were successfully identified based on analysis of the Tn5 transposon insertion site. Indeed, this result indicated that three mutants were inserted on an indigenous plasmid in which the same insertion site was observed in two mutants. In addition, the remaining eight mutants were inserted on different genes encoding glycosyl transferase, histone H1, nonribosomal peptide synthetase, methyltransferase, MnmG, sulfate export transporter, catalase/peroxidase HPI and CysD, respectively. Compared to the wild type, the 11 mutants showed a differential effect in bacteriological characteristics such as cell growth, biofilm formation and response to HO stress, revealing the complexity of action mode of these antagonism-related genes. However, a significant reduction of cell motility was observed in the 11 mutants compared to the wild type. Therefore, it can be inferred that the antifungal mechanism of the 10 above-mentioned genes may be, at least partially, due to the weakness of cell motility. Overall, the result of this study will be helpful for us to understand the biocontrol mechanism of this bacterium.
是水稻纹枯病的致病因子。在之前的一项研究中，我们发现菌株R456抑制了的生长。因此，本研究通过使用Tn5转座子突变方法来鉴定参与菌株R456抗真菌活性的基因。首先，我们构建了一个包含997个突变体的随机插入转座子文库，其中11个突变体对表现出抗真菌活性缺陷。此外，基于对Tn5转座子插入位点的分析，成功鉴定出10个与拮抗作用相关的基因。事实上，这一结果表明，有三个突变体插入到一个内源质粒上，在两个突变体中观察到相同的插入位点。此外，其余八个突变体分别插入到编码糖基转移酶、组蛋白H1、非核糖体肽合成酶、甲基转移酶、MnmG、硫酸盐输出转运蛋白、过氧化氢酶/过氧化物酶HPI和CysD的不同基因上。与野生型相比，这11个突变体在细胞生长、生物膜形成和对HO应激反应等细菌学特征方面表现出不同的影响，揭示了这些拮抗作用相关基因作用模式的复杂性。然而，与野生型相比，在这11个突变体中观察到细胞运动性显著降低。因此，可以推断上述10个基因的抗真菌机制可能至少部分是由于细胞运动性减弱。总体而言，本研究结果将有助于我们理解这种细菌的生物防治机制。
