Figure 7.

The MtCEP1 effect on nodule number but not LR or pseudonodules numbers is impaired by AVG. A, Quantification of nodule number in S. meliloti WSM1022-inoculated plants grown on N-free Fåhraeus medium with or without the MtCEP1 peptide and/or AVG (1 μm). Nodules were counted 2 weeks postinoculation. Error bars represent se (n ≥ 6; one-way ANOVA, P ≤ 0.05). B, Quantification of emerged LRs in plants grown on a 5 mm KNO₃ Fåhraeus medium with or without the MtCEP1 peptide and/or AVG (1 μm). LR number was quantified 14 d after germination. Error bars represent se (n ≥ 20; one-way ANOVA, P ≤ 0.05). C, Quantification of the ethylene production in single seedlings treated with or without the MtCEP1 peptide or the cytokinin BAP (0.01 μm), and/or the ethylene synthesis inhibitor AVG (1 μm). BAP and AVG were used as positive and negative controls, respectively, for the detection of increased or decreased ethylene levels. Ethylene was measured using laser-based trace gas detection 24 h after treatment. Error bars represent confidence interval (α < 0.05; n ≥ 6). D, Quantification of TIBA-induced pseudonodule and LR numbers with or without the MtCEP1 peptide. The numbers of LRs (left side) and pseudonodules (right side) were counted 2 weeks post-TIBA addition. Error bars represent se (n ≥ 52; Student’s t test, ***: P ≤ 0.001). FW, Fresh weight.