%D 1998 %0 ARTICLE %T Xa21D encodes a receptor-like molecule with a leucine-rich repeat domain that determines race-specific recognition and is subject to adaptive evolution . %J Plant Cell %V 10 ( 5 ) %P 765-79 %A Wang GL %A Ruan DL %A Song WY %A Sideris S %A Chen L %A Pi LY %A Zhang S %A Zhang Z %A Fauquet C %A Gaut BS %A Whalen MC %A Ronald PC %M pub9596635 %X The rice Xa21 gene confers resistance to Xanthomonas oryzae pv oryzae in a race-specific manner . Analysis of the inheritance patterns and resistance spectra of transgenic plants carrying six Xa21 gene family members indicated that one member , designated Xa21D , displayed a resistance spectrum identical to that observed for Xa21 but conferred only partial resistance . Xa21D encodes a receptor-like protein carrying leucine-rich repeat ( LRR ) motifs in the presumed extracellular domain . The Xa21D transcript terminates shortly after the stop codon introduced by the retrotransposon Retrofit . Comparison of nucleotide substitutions in the LRR coding regions of Xa21 and Xa21D provided evidence of adaptive selection . Both functional and evolutionary evidence indicates that the Xa21D LRR domain controls race-specific pathogen recognition .