THE PLASMID PVM OF SAPROPHYTE NITROGEN-FI XING AGROBACTERIUM-RADIOBACTER 5D-1

In order to elucidate the role of large cryptic plasmid pVM of saproph yte nitrogen fixing strain Agrobacterium radiobacter 5D-1 in associati ve relationship of this strain with plants, the Tn5-mob transposon was introduced into the plasmid. This fact permitted to mobilize pVM with the help of plasmid RP4kan into cells of plasmid-less strain A. tumef aciens UBAPF2. Comparative analysis of indoleacetic acid contents in c ulture broth, of the efficiency of nitrogen fixation in transconjugant s A. tumefaciens UBAPF2(pVM) and in strains A. tumefaciens UBAPF2, A. radiobacter 5-D1, and A. tumefaciens C58 showed that plasmid pVM is no t involved in synthesis of indoleacetic acid and nitrogen fixation in A. radiobacter 5-D1. In addition, plasmid pVM has no conjugative prope rties.