부산대학교 도서관

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1469-8137.2007.02346.x Byline: Jason A. Holliday (1), Steven G. Ralph (2), Richard White (3), Jorg Bohlmann (1,2,4), Sally N. Aitken (1) Keywords: adaptation; cold hardiness; genetic cline; microarray; real-time polymerase chain reaction (PCR); Sitka spruce (Picea sitchensis) Abstract: Summary Cold acclimation in conifers is a complex process, the timing and extent of which reflects local adaptation and varies widely along latitudinal gradients for many temperate and boreal tree species. Despite their ecological and economic importance, little is known about the global changes in gene expression that accompany autumn cold acclimation in conifers. Using three populations of Sitka spruce (Picea sitchensis) spanning the species range, and a Picea cDNA microarray with 21 840 unique elements, within- and among-population gene expression was monitored during the autumn. Microarray data were validated for selected genes using real-time PCR. Similar numbers of genes were significantly twofold upregulated (1257) and downregulated (967) between late summer and early winter. Among those upregulated were dehydrins, pathogenesis-related/antifreeze genes, carbohydrate and lipid metabolism genes, and genes involved in signal transduction and transcriptional regulation. Among-population microarray hybridizations at early and late autumn time points revealed substantial variation in the autumn transcriptome, some of which may reflect local adaptation. These results demonstrate the complexity of cold acclimation in conifers, highlight similarities and differences to cold tolerance in annual plants, and provide a solid foundation for functional and genetic studies of this important adaptive process. Author Affiliation: (1)Department of Forest Sciences, University of British Columbia; (2)Michael Smith Laboratories, University of British Columbia; (3)Department of Statistics, University of British Columbia; (4)Department of Botany, University of British Columbia, BC, Canada V6T 1Z3 Article History: Received: 18 November 2007Accepted: 21 November 2007 Article note: Author for correspondence:, Sally Aitken, Tel:+604 822 6020, Fax:+604 822 9102, Email: sally.aitken@ubc.ca