Table I.

Matching pairs of cloned R and Avr genes

R Gene	Isolated from	Matching Avr Gene	Pathogen	Reference
Pto	Tomato	AvrPto	Pseudomonas syringae pv tomato	Martin et al. (1993)
RPS2	Arabidopsis	AvrRpt2	P. syringae pv tomato	Bent et al. (1994)
RPM1/RPS3	Arabidopsis	AvrRpm1/AvrB	P. syringae pv maculicola	Grant et al. (1995)
				Bisgrove et al. (1994)
Cf-4	Tomato	Avr4	C. fulvum	Thomas et al. (1997)
Cf-9	Tomato	Avr9	C. fulvum	Jones et al. (1994)