FIG. 7.

Kinetics of nodule formation exhibited by the wild type and nodPQ, cysH, and nodS mutants. Sterile L. japonicus seedlings were cultured on B&D agar slants supplemented with 40 nM AVG. Plants were inoculated 48 h after transfer to B&D agar slants with either wild-type M. loti, the nodPQ, cysH, or nodS mutant, or sterile 10 mM MgSO₄. (A) At various intervals following inoculation, the number of nodules was counted as described in Materials and Methods for wild-type M. loti (wt), the nodPQ, cysH, or nodS mutant, or sterile 10 mM MgSO₄. (B) Plants were harvested at 120 days postinoculation, and their dry weight was measured. Lane 1, wild-type M. loti; lane 2, nodPQ; lane 3, cysH; lane 4, nodS; lane 5, sterile 10 mM MgSO₄.