Plant shoot length in cm, 5 weeks after inoculation with deletion mutant strains (summarized in Table 3). For each of the ORF deletions, the plant phenotype of at least two isolates/and or transductants of each strain are shown. Mean values are given above graph bars. Error bars represent standard error of the mean. Asterisks indicate samples with mean heights significantly different from the wild type. The number of plants tested and the number of nodules/plant for these assays are presented in Table 4.