A new root-nodulating symbiont of the tropical legume Sesbania, Rhizobium sp. SIN-1, is closely related to R. galegae, a species that nodulates temperate legumes.
Rhizobium sp. SIN-1, isolated in India from root nodules on the tropical legume Sesbania aculeata, also induces nitrogen-fixing nodules on roots of S. macrocarpa, S. speciosa, S. procumbens, S. punicea, S. rostrata, and Vigna unguiculata. Unlike Azorhizobium caulinodans, SIN-1 does not induce stem nodules on S. rostrata. The nodules induced by SIN-1 develop exclusively at the bases of secondary roots. Electron microscopic studies of mature nodule sections revealed rhizobia within intercellular spaces, indicating a 'crack entry' mechanism of root infection. SIN-1 is a fast-growing, acid-producing, salt-tolerant Rhizobium that utilizes a wide variety of carbon sources. The nodulation (nod) genes of this strain are located on a 300-MDa symbiosis (sym) plasmid. Fatty acid profile and sequence comparison of a 260-bp conserved region of the 16S rRNA gene demonstrated that SIN-1 is phylogenetically closely related to R. galegae, a species that nodulates temperate legumes.
Rana
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Department of Plant Pathology, University of Missouri, Columbia 65211, USA.
Krishnan
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D001483:Base Sequence; D007887:Fabaceae / Q000382:microbiology*; D005227:Fatty Acids / Q000032:analysis; D005798:Genes, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D010946:Plants, Medicinal; D010957:Plasmids / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000737:chemistry / Q000145:classification / Q000502:physiology*; D016415:Sequence Alignment
D005227:Fatty Acids; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S