Wide distribution range of rhizobial symbionts associated with pantropical sea-dispersed legumes

• Published in: Antonie van Leeuwenhoek Vol. 109; no. 12; pp. 1605 - 1614
• Main Authors: Bamba, Masaru, Nakata, Sayuri, Aoki, Seishiro, Takayama, Koji, Núñez-Farfán, Juan, Ito, Motomi, Miya, Masaki, Kajita, Tadashi
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-12-2016; Springer Nature B.V
• Subjects: Bacteria; Bacterial Proteins - genetics; Biogeography; Biomedical and Life Sciences; Bradyrhizobium; Bradyrhizobium - classification; Bradyrhizobium - isolation & purification; Canavalia rosea; Coastal zone; Dispersal; Fabaceae - microbiology; Genes, Bacterial; Geographical distribution; Legumes; Life Sciences; Medical Microbiology; Microbiology; Molecular Typing; N-Acetylglucosaminyltransferases - genetics; Original Paper; Pacific Ocean; Phylogeny; Plant Sciences; Rhizobiaceae - classification; Rhizobiaceae - genetics; Rhizobiaceae - isolation & purification; Rhizobium - classification; Rhizobium - isolation & purification; RNA, Bacterial; RNA, Ribosomal, 16S - genetics; Seeds; Sinorhizobium; Sinorhizobium - classification; Sinorhizobium - isolation & purification; Soil microorganisms; Soil Science & Conservation; Symbiosis; Vigna luteola; Vigna marina; Sea dispersal; Pantropical plants with sea-drifted seeds; Rhizobia biogeography
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-016-0761-y

To understand the geographic distributions of rhizobia that associated with widely distributed wild legumes, 66 nodules obtained from 41 individuals including three sea-dispersed legumes (
Vigna marina
,
Vigna luteola
, and
Canavalia rosea
) distributed across the tropical and subtropical coastal regions of the world were studied. Partial sequences of 16S rRNA and
nodC
genes extracted from the nodules showed that only
Bradyrhizobium
and
Sinorhizobium
were associated with the pantropical legumes, and some of the symbiont strains were widely distributed over the Pacific. Horizontal gene transfer of nodulation genes were observed within the
Bradyrhizobium
and
Sinorhizobium
lineages. BLAST searches in GenBank also identified records of these strains from various legumes across the world, including crop species. However, one of the rhizobial strains was not found in GenBank, which implies the strain may have adapted to the littoral environment. Our results suggested that some rhizobia, which associate with the widespread sea-dispersed legume, distribute across a broad geographic range. By establishing symbiotic relationships with widely distributed rhizobia, the pantropical legumes may also be able to extend their range much further than other legume species.