부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.postharvbio.2006.11.008 Byline: Jennifer M. Ghosoph (a), Leigh S. Schmidt (a), Dennis A. Margosan (b), Joseph L. Smilanick (b) Keywords: Penicillium digitatum; Demethylation inhibitors (DMIs); Fungicide resistance; Imazalil; 14[alpha]-Demethylase CYP51 gene Abstract: Two mechanisms of resistance to the fungicide imazalil (IMZ) existed among California strains of Penicillium digitatum, cause of citrus green mold. Sensitive (S; n =50) strains did not grow on IMZ above 0.1[mu]gmL.sup.-1, while those resistant (R; n =59) grew [greater than or equal to]0.5mgL.sup.-1. After amplification of the promoter region of the CYP51 gene, fragments 250, 450, and 750bp in size were generated. All S strains had a 250bp product, while among R strains, 47 had a 450bp product and 12 had a 750bp product. The 450bp unit was common among R strains, while the 750bp unit, reported previously by others, was not. The promoter region of all was identical; variations occurred in the region's transcriptional enhancer unit. S strains with a 250bp product and R strains with a 750bp product had one and five copies, respectively, of a 126bp transcriptional enhancer unit. R strains with a 450bp product had a unique 199bp insert within the 126bp transcriptional enhancer unit with no known sequence correlations (GenBank). Both types of R strains exhibited significantly elevated expression, approximately 10-fold, of the target site CYP51 gene, indicating its overexpression was the mechanism of resistance. Author Affiliation: (a) Department of Biology, California State University, Fresno, CA 93710, United States (b) USDA-ARS, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, Parlier, CA 93648, United States Article History: Received 21 March 2006; Accepted 12 November 2006