Interaction between plants and microbes


     Methylobacterium species are considered as important bacteria residing on plant surface. They are a member of methylotrophs, that can utilize one-carbon compounds like methanol as a sole carbon source. The reason of the predomination of the species on plant surface is the emission of methanol from plants. We isolated and characterized Methylobacterium species from a moss, Racomitrium japnoicum, which is utilized for roof greening. The isolates could strongly promote the growth of the moss. Furthermore we isolated many novel species from many samples of plants. As a strategy for selecting novel species, we utilized whole-cell mass spectrometry with MALDI-TOF/MS. These results are already published.
      Now we are focusing on the predomination mechanism. It is not only that they can utilize methanol. Why and how Methylobacterium species can reside in the phyllosphere?
      In one of our recent publication, we found one of the methanol dehydrogenase proteins in Methylobacterium species is not traditional calcium-dependent enzyme but lanthanum-dependent enzyme. Lanthanoids have never been recognized as important metals for any organisms. The most abundant bacteria in the phyllosphere are utilizing these metals? This finding will broaden our research field on methylotrophy.
      In addition we are interested in their ability to promote plant growth. Every year we grow rice and barley in the field. We are also investigating the genes involved in plant growth promotion.

Students from abroad are welcome to contact us.

Akio TANI
atani###rib.okayama-u.ac.jp