Nodule Specific Novel Genes Induced by Infection of Rhizobium Huakuii bv. Renge in Astragalus Sinicus (Chinese Milk Vetch)

Astragalus sinicus (renge-sou) is a winter growing green manure legume, and its divergent strains have been widely used to fertilize rice field in China and Japan and has been used for 2,000 years. The plant forms nitrogen-fixing root nodules by Rhizobium huakuii or R. huakuii bv. renge (Y. Murooka et al., 1993). Formation of adventitious shoots and plant regeneration by culture of cotyledon segment in A. sinicus were established (H-J. Cho et al., 1995). We also developed transformation and regeneration of A. sinicus with Agrobacterium rhizogenes DC-AR2 harboring pBI12l. Transformation frequencies of up to 90% was obtained. Mikimopine formation and GUS activity were observed in these transformants (H-J. Cho et al., unpublished). Shoots were spontaneously formed on hairy root cultures and thus transgenic A. sinicus plantlets were established.