Plant shoot length in cm, 5 weeks after inoculation with insertion mutant strains (mutant strain information is summarized in Table 3). For each of the 6 ORF disruptions, the plant phenotype of the original isolate and that of a phage ϕM12 transductant of that 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.