RRC ID 60721
著者 Kusakabe S, Higasitani N, Kaneko T, Yasuda M, Miwa H, Okazaki S, Saeki K, Higashitani A, Sato S.
タイトル Lotus Accessions Possess Multiple Checkpoints Triggered by Different Type III Secretion System Effectors of the Wide-Host-Range Symbiont Bradyrhizobium elkanii USDA61.
ジャーナル Microbes Environ
Abstract 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.
巻・号 35(1)
公開日 2020-2-20
DOI 10.1264/jsme2.ME19141
PMID 32074548
PMC PMC7104275
MeSH Bacterial Proteins / genetics Bradyrhizobium / genetics Bradyrhizobium / metabolism Bradyrhizobium / physiology* Genotype Host Specificity / genetics Lotus / genetics Lotus / microbiology* Plant Root Nodulation / genetics Symbiosis / genetics* Type III Secretion Systems / genetics*
IF 2.575
リソース情報
ミヤコグサ・ダイズ Gifu B-129 Miyakojima MG-20 L. burttii B-303