Yamada Takashi, Kawasaki Takeru, Nagata Shoko, Fujiwara Akiko, Usami Shoji, Fujie Makoto
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan.
Microbiology (Reading). 2007 Aug;153(Pt 8):2630-2639. doi: 10.1099/mic.0.2006/001453-0.
Four kinds of bacteriophage (phiRSL, phiRSA, phiRSM and phiRSS) were isolated from Ralstonia solanacearum, a soil-borne Gram-negative bacterium that is the causative agent of bacterial wilt in many important crops. The Myovirus-type phages phiRSL1 and phiRSA1 contained dsDNA genomes of 240 kbp and 39 kbp, respectively. These phages have relatively wide host ranges and gave large clear plaques with various host strains; especially phiRSA1 was able to infect all 15 R. solanacearum strains of different races or different biovars tested in this study. Three host strains contained phiRSA1-related sequences in their genomic DNAs, suggesting a lysogenic cycle of phiRSA1. Two phages, phiRSM1 and phiRSS1, were characterized as Ff-type phages (Inovirus) based on their particle morphology, genomic ssDNA and infection cycle. However, despite their similar fibrous morphology, their genome size (9.0 kb for phiRSM1 and 6.6 kb for phiRSS1) and genome sequence were different. Strains of R. solanacearum that were sensitive to phiRSM1 were resistant to phiRSS1 and vice versa. Several R. solanacearum strains contained phiRSM1-related sequences and at least one strain produced phiRSM1 particles, indicating the lysogenic state of this phage. These phages may be useful as a tool not only for molecular biological studies of R. solanacearum pathogenicity but also for specific and efficient detection (phiRSM1 and phiRSS1) and control of harmful pathogens (phiRSL and phiRSA) in cropping ecosystems as well as growing crops.
从青枯雷尔氏菌中分离出了四种噬菌体（phiRSL、phiRSA、phiRSM和phiRSS），青枯雷尔氏菌是一种土壤传播的革兰氏阴性细菌，是许多重要作物中细菌性枯萎病的病原体。肌尾病毒型噬菌体phiRSL1和phiRSA1分别含有240 kbp和39 kbp的双链DNA基因组。这些噬菌体具有相对广泛的宿主范围，能在各种宿主菌株上形成大的清晰噬菌斑；特别是phiRSA1能够感染本研究中测试的所有15种不同种族或不同生化变种的青枯雷尔氏菌菌株。三种宿主菌株的基因组DNA中含有与phiRSA1相关的序列，这表明phiRSA1存在溶原周期。基于其颗粒形态、基因组单链DNA和感染周期，两种噬菌体phiRSM1和phiRSS1被鉴定为丝状噬菌体（丝杆病毒）。然而，尽管它们的纤维形态相似，但其基因组大小（phiRSM1为9.0 kb，phiRSS1为6.6 kb）和基因组序列不同。对phiRSM1敏感的青枯雷尔氏菌菌株对phiRSS1具有抗性，反之亦然。几种青枯雷尔氏菌菌株含有与phiRSM1相关的序列，并且至少有一个菌株产生phiRSM1颗粒，这表明该噬菌体处于溶原状态。这些噬菌体不仅可能作为研究青枯雷尔氏菌致病性的分子生物学工具，还可能作为种植生态系统以及生长作物中有害病原体（phiRSL和phiRSA）的特异性高效检测（phiRSM1和phiRSS1）及控制工具。
