- 著者
- Khoa Lai Ngoc Thai Nguyen Michiko Yasuda Khondoker M.G. Dastogeer Atsushi Toyoda Koichi Higashi Ken Kurokawa Nga Thi Thu Nguyen Ken Komatsu Shin Okazaki
- 出版者
- Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
- 雑誌
- Microbes and Environments (ISSN:13426311)
- 巻号頁・発行日
- vol.36, no.4, pp.ME21035, 2021 (Released:2021-11-03)
- 参考文献数
- 46
A new disease in rice that is characterized by leaf bleaching was recently identified in some fields in the Mekong Delta region of Vietnam. The present study was the first to isolate and identify the pathogen of this disease. We confirmed that leaf bleaching symptoms were due to infection with Methylobacterium indicum bacteria using molecular biology approaches. A full-length genome analysis of pathogenic Methylobacterium strain VL1 revealed that it comprises a single chromosome and six plasmids, with a total size of 7.05 Mbp and GC content of 70.5%. The genomic features of VL1 were similar to those of the non-pathogenic M. indicum strain SE2.11T; however, VL1 possessed additional unique genes, including those related to homoserine lactone biosynthesis. We established a loop-mediated isothermal amplification (LAMP) assay using the unique sequences of VL1 as target sequences for the rapid and simple detection of pathogenic M. indicum strains. Our initial evaluation demonstrated that the LAMP assay successfully distinguished between pathogenic and non-pathogenic strains infecting rice plants in a rapid and sensitive manner. The present results provide insights into the pathogenesis and development of control measures for novel rice diseases.
- 著者
- Shohei Kusakabe Nahoko Higasitani Takakazu Kaneko Michiko Yasuda Hiroki Miwa Shin Okazaki Kazuhiko Saeki Atsushi Higashitani Shusei Sato
- 出版者
- Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
- 雑誌
- Microbes and Environments (ISSN:13426311)
- 巻号頁・発行日
- vol.35, no.1, pp.ME19141, 2020 (Released:2020-02-20)
- 参考文献数
- 65
- 被引用文献数
- 20
Bradyrhizobium elkanii, a rhizobium with a relatively wide host range, possesses a functional type III secretion system (T3SS) that is involved in symbiotic incompatibility against Rj4-genotype soybean (Glycine max) and some accessions of mung bean (Vigna radiata). To expand our knowledge on the T3SS-mediated partner selection mechanism in the symbiotic legume-rhizobia association, we inoculated three Lotus experimental accessions with wild-type and T3SS-mutant strains of B. elkanii USDA61. Different responses were induced by T3SS in a host genotype-dependent manner. Lotus japonicus Gifu inhibited infection; L. burttii allowed infection, but inhibited nodule maturation at the post-infection stage; and L. burttii and L. japonicus MG-20 both displayed a nodule early senescence-like response. By conducting inoculation tests with mutants of previously reported and newly identified effector protein genes of B. elkanii USDA61, we identified NopF as the effector protein triggering the inhibition of infection, and NopM as the effector protein triggering the nodule early senescence–like response. Consistent with these results, the B. elkanii USDA61 gene for NopF introduced into the Lotus symbiont Mesorhizobium japonicum induced infection inhibition in L. japonicus Gifu, but did not induce any response in L. burttii or L. japonicus MG-20. These results suggest that Lotus accessions possess at least three checkpoints to eliminate unfavorable symbionts, including the post-infection stage, by recognizing different T3SS effector proteins at each checkpoint.