Inhibition of Soybean Cell Growth by the Adsorption of Rhizobium japonicum.

Soybean cells in suspension culture were inhibited in their growth by mixed culture with Rhizobium japonicum 5033. Rhizobium cells had the ability to adsorb on the surface of soybean cells. Cell envelope prepared from Rhizobium by sonic oscillation inhibited the growth of soybean cells. The growth-inhibiting activity of the cell envelope was depressed by beta-glucosidase, KIO(4), urea, sodium cholate, and Triton X-100, but was stable on heating at 120 C for 15 minutes. Adsorption of the cell envelope on soybean cells was depressed by only beta-glucosidase. The sodium cholate-soluble fraction of the cell envelope had the growth-inhibiting activity. Results in this paper suggest that components of the Rhizobium cell surface cause the inhibition of soybean cell growth after the adsorption of the Rhizobium cell to the soybean cell.