Find in Library

Effector proteins secreted by plant pathogens play important roles in promoting colonization. <i>Blumeria</i> effector candidate (<i>BEC</i>) 1019, a highly conserved metalloprotease of <i>Blumeria graminis</i> f. sp. <i>hordei</i> (<i>Bgh</i>), is essential for fungal haustorium formation, and silencing <i>BEC1019</i> significantly reduces <i>Bgh</i> virulence. In this study, we found that <i>BEC1019</i> homologs in <i>B. graminis</i> f. sp. <i>tritici</i> (<i>Bgt</i>) and <i>Gaeumannomyces graminis</i> var. <i>tritici</i> (<i>Ggt</i>) have complete sequence identity with those in <i>Bgh</i>, prompting us to investigate their functions. Transcript levels of <i>BEC1019</i> were abundantly induced concomitant with haustorium formation in <i>Bgt</i> and necrosis development in <i>Ggt</i>-infected plants. <i>BEC1019</i> overexpression considerably increased wheat susceptibility to <i>Bgt</i> and <i>Ggt</i>, whereas silencing this gene using host-induced gene silencing significantly enhanced wheat resistance to <i>Bgt</i> and <i>Ggt</i>, which was associated with hydrogen peroxide accumulation, cell death, and pathogenesis-related gene expression. Additionally, we found that the full and partial sequences of <i>BEC1019</i> can trigger cell death in <i>Nicotiana benthamiana</i> leaves. These results indicate that <i>Bgt</i> and <i>Ggt</i> can utilize <i>BEC1019</i> as a virulence effector to promote plant colonization, and thus these genes represent promising new targets in breeding wheat cultivars with broad-spectrum resistance.