FIG. 2.

Acetylene reduction activity associated with 2,4-D-treated plants inoculated with Sp7, Sp7-S, or Sp7-S complemented for flocculation with plasmid clone pAB1220-9. The assays were carried out in a modified atmosphere containing 2.5% oxygen and lasted for 10 h from the injection of acetylene. The data shown are averages of five plants, grown for 10 days after inoculation. No ethylene was detected in noninoculated plants or in controls without acetylene. The error bars indicate standard errors.