FIG. 5.

Effects on hrpA′::uidA expression of altering the levels of expression of hrpV, hrpL, and hrpS. Bacteria were grown in KB medium to stationary phase and transferred to Hrp minimal medium at an initial OD₆₀₀ of 0.5. β-Glucuronidase activity and total protein concentration were measured at the indicated times as described in the text. The values represent the means of three replicates. The vertical lines indicate standard errors, and where they are absent, the limits were within the symbol dimensions. Except where noted, all strains carried pCPP2383 (hrpA′::uidA). The strains tested were P. syringae pv. syringae 61–N407 (hrpV−), P. syringae pv. syringae 61–2088 (hrcU−), P. syringae pv. syringae 61 (WT), P. syringae pv. syringae 61–N407(pCPP2371) (hrpV−/hrpV++), P. syringae pv. syringae 61–2095 (hrpS−), P. syringae pv. syringae 61(pCPP2371) (hrpV++), P. syringae pv. syringae 61–2074 (hrpL−), and P. syringae pv. syringae 61 without pCPP2383 (WT w/o hrpA′::uidA). MU, methylumbelliferone.