30th Aug (Thu) 17:30 - 19:00

Evolution and diversity of Legume - Soil Bacteria Symbiosis

The mutualistic symbiosis between legume plants and the soil bacteria called rhizobia is a rather complicated interaction that results in the development of nitrogen-fixing root nodules. Through nodulation with the rhizobia, legumes obtain ammonia from the atmospheric nitrogen, which results in legumes being a rich source of protein. Despite Leguminosae being one of the largest families of plants, only a small number of species had been studied with regard to their symbiotic rhizobia, until recent years. These were mainly those of agricultural interest. This situation has changed in the last two decades, through applying sequencing techniques to bacterial taxonomy and the isolation of root nodule bacteria from many legume species worldwide. Consequently, a huge unexpected diversity of rhizobia is being revealed. Current challenges in studying the legume-root nodule bacteria symbiosis include the need to extend our understanding of rhizobial diversity to previously unresearched legumes, in particular to ecologically important wild legumes growing in different geographic zones and contrasting habitats. This symposium will comprise several talks, including different aspects of the rhizobia-Lotus symbiosis in the Canary Islands, using traditional sequencing techniques and metagenomic analysis.

ORGANIZERS: Milagros Leon Barrios (La Laguna University, Spain); Kojiro Takanashi (Shinshu University, Japan); Tadashi Kajita (University of the Ryukyus, Japan)

1. Wide diversity of the endemic Lotus and their symbiotic rhizobia in the Canary Islands: an overview
Milagros Leon-Barrios*1, Marcelino del Arco-Aguilar2 (1Department of Biochemistry, Microbiology, Cell Biology and Genetics. Universidad de La Laguna. Tenerife. Canary Islands. Spain.;2Department of Botany, Ecology and Plant Physiology. Universidad de La Laguna. Tenerife. Canary Islands. Spain. )

2. Lotus species in Canary Islands and noduling bacterial communities in their habitats
Masaru BAMBA*1, Milagros León-Barrios2, Marcelino del Arco-Aguilar2, Seishiro Aoki3, Koji Takayama4, Tadashi Kajita5 (1Graduate school of Science and Engineering, Chiba University;2Universidad La Laguna;3Graduate School of Science, the University of Tokyo;4Graduate school of Science, Kyoto University;5Iriomote Station, Tropical Biosphere Research Center, University of the Ryukyus )

3. Comparative genome analysis of rhizobia associated with Japanese accessions of Lotus japonicus
Hiroko Maita1, Mingzhuo Wang1, Shogo Nitanada1, Shohei Kusakabe1, Hideki Hirakawa2, Kazuhiko Saeki3, Shusei Sato*1 (1Graduate School of Life Sciences, Tohoku University;2Kazusa DNA Research Institute;3Faculty of Science, Nara Women )

4. Dispersal of Oxytropis-rhizobia symbiosis from the Arctic to Japanese alpine region
Kojiro Takanashi* (Fac. Sci., Shinshu University)

5. From Beta- to Alpha-proteobacteria: The origin and evolution of rhizobial nodulation genes nodIJ
Seishiro Aoki*1, Motomi Ito2, Wataru Iwasaki1 (1Graduate School of Science, The University of Tokyo;2Graduate School of Arts and Sciences, The University of Tokyo )

6. Experimental evolution of bradyrhizobial symbiosis island by symbiotic incompatibility
Kiwamu Minamisawa* (Graduate School of Life Sciences, Tohoku University)