| Abstract: | The water extracts of leaves and roots from supernodulating soybean (Glycine max (L.) Merr. ) nts 382 and nonnodulating soybean Nod 49 have been chromatographed using filtering method through the column (25 cm × 2 cm) Sephadex G25 and 4 fractions, namly, nts 382 (Nod 49) F1, nts 382 (Nod 49) F2, nts 382 (Nod 49) F3, and nts 382 (Nod 49) F4 could be distinguished according to nitrate reductase (NR) activities inhibited by the eluate. The inhibition of NR activity by the noninoculated nts 382 F2 and the nts 382 F4 in vitro were much stronger than that by the inoculated nts 382 F2 and nts 382 F4. On the contrary, the obvious inhibition of NR activity in vitro by the noninoculated Nod 49 F2 and Nod 49 F4 were substantialy strengthed again by the innoculated Nod 49 F2 and Nod 49 F4. The facts indicated that the quantity of NR inhibitors in the leaf cells of soybean nts 382 reduced after the inoculation but was that in the inoculated Nod 49 leaf cells further more accumulated. Both nodulations assays, the nodulation of soybean "Bragg " injected with inoculated nts 382 Fl, nts 382 F2, nts 382 F3 and nts 382 F4 from leaves and roots and the nodulation of soybean nts 382 injected with inoculated Nod 49 F2, Nod 49 F3 and Nod 49 F4 from leaves only showed that nts 382 Fl and nts 382 F2 increased nodules of soybean "Bragg" by 1 to 3 times but nts 382 F3 and nts 382 F4 did not. Inhibition of soybeannts 382 nodulation by inoculated Nod 49 F2 Nod 49 F3 and Nod 49 F4 expressed that the Nod 49 F4 only inhibited the nodulation strongly by one time in the experiments with nts 382 plants with leaves, and by 15 times in the experiments with nts 382 plants without leaves at 10 d of inoculation and injection and this inhibition was nonreversible even after stopping injection from the 11th day to the 15th day after inoculation. |
