Table 1.

The structures of known genes conferring resistance to Puccinia spp. in cereals (Cloutier et al. 2007; Brueggeman et al. 2008; Fu et al. 2009; Krattinger et al. 2009; updated from Ayliffe and Lagudah 2004). Despite the general trend presented here, lack of durability is not exclusively or even necessarily associated with the NBS-LRR forms of resistance genes, as illustrated by the emergence of pathotype Pgt-QCC virulent on the long-deployed barley stem rust resistance gene Rpg1 (a protein kinase) (Martens et al. 1989; Jin et al. 1994; Brueggeman et al. 2002) and the current efficacy of the leaf rust resistance gene Lr21 (an NBS-LRR gene of limited deployment) against all known races of leaf rust (Huang et al. 2009)

Major resistance genes with known or predicted race specificity
Species	Gene	Putative gene product	Disease
Wheat	Lr1	CC-NBS-LRR	Leaf rust
	Lr10	NBS-LRR	Leaf rust
	Lr21	NBS-LRR	Leaf rust
Maize	Rp1-D	NBS-LRR	Leaf rust
	Rp3	NBS-LRR	Leaf rust
Barley	Rpg1	Kinase-kinase	Stem rust
	Rpg5	NBS-LRR-Kinase	Stem rust
Partial resistance genes with possible race non-specificity
Wheat	Lr34/Yr18/Pm38	ABC transporter	Leaf rust/stripe rust/powdery mildew
	Yr36	Kinase-START	Stripe rust