Figure 1.

Phenotypes of plants with all five NPD genes knocked out (npd1–5) differed from wild-type (WT) M. truncatula plants more than plants with the NPD2 gene knocked out differed from wild type. Measured phenotypes are as follows: mean nodule size (A), nodule number per plant (B) colony-forming rhizobia per nodule (C), percent pink nodules (D), and plant biomass (E). Letters indicate between-group differences in the multi-strain inoculation experiment based on ANOVA (P < 0.05; P adjusted for three contrasts via Tukey method). Solid points indicate average values in multi-strain inoculations for each pot replicate (median of 5.5 plants per pot). Hollow triangles indicate single-strain (Sm1021-only) inoculations.