TABLE 2.

Activities of hrpR, hrpS, and hrpL promoter constructs in P. syringae Pss61, P. syringae DC3000, and E. coli MC4100

Strain	hrpRS expresseda	β-Galactosidase activity from promoter fusionb:
		Nonec	hrpRd	hrpSe	hrpLf
Pss61	−	3 ± 1	417 ± 16	31 ± 1	348 ± 16
	+	3 ± 1	615 ± 38	40 ± 1	3,469 ± 184
DC3000	−	4 ± 1	126 ± 2	7 ± 3	57 ± 4
	+	6 ± 1	147 ± 4	9 ± 1	216 ± 8
MC4100	−	1 ± 1	439 ± 23	6 ± 1	5 ± 1
	+	1 ± 1	364 ± 19	5 ± 1	271 ± 5

^aThe indicated strains carried pDSK519 (−) or pNTR3D to ectopically express hrpRS (+). 

^bStrains carrying the indicated reporter construct were grown overnight to an OD₆₀₀ of 1.0, harvested, washed and used to inoculate inductive M63 fructose (pH 5.5) medium for P. syringae strains or King's B medium for E. coli MC4100. After 6 h of growth, β-galactosidase activity was determined by the procedures of Miller (36). The data reported are the means of values from a single experiment done in triplicate. Errors represent standard deviations. Each experiment was repeated at least three times with similar results. 

^cIndicated strain carrying pRG970. 

^dPss61 carrying pDRR1R, DC3000 carrying pJBR6R, or MC4100 carrying pDRR1R. 

^ePss61 carrying pTSR4R, DC3000 carrying pJBR7R, or MC4100 carrying pTSR4R. 

^fIndicated strain carrying pYXL1R.