FUNCTIONAL GENOMICS IN LOBLOLLY PINE AND EASTERN COTTONWOOD

¹ ArborGen, PO Box 840001, Summerville, SC 29484, USA

² Genesis Research and Development, PO Box 50, Auckland, New Zealand

ArborGen is applying the principles of high-throughput functional genomics to both angiosperm and conifer trees. Our goals are the functional testing of genes that affect wood quality traits and productivity, as well as defining promoter function in tree species. The ability to demonstrate gene function in commercially important tree species is a key requirement for developing improved tree products based on gene transfer. Starting with a large database of ESTs isolated from Pinus radiata and Eucalyptus grandis, a systematic approach to uncovering gene function is in progress. Our tree functional testing platforms are Populus deltoides (Eastern cottonwood), and Pinus taeda (Loblolly pine). We have developed efficient transformation protocols to introduce large numbers of gene constructs into these tree species. In development are methods for early detection of transgene function based on phenotypic and chemical composition screens in tissue culture, greenhouse plants, and field grown plants. Early screening of transgenic tissue cultures and plantlets has identified lines with phenotypes suggesting potentially valuable uses. Novel methods for performance testing in container grown trees are also being employed in uncovering transgene function. Promoter function is being tested from tissue culture stages through multi-year field trials. These methods will enable ArborGen to functionally test several hundred gene constructs per year in trees. These functional screens are being used to identify promoters and candidate genes that are expected to affect key commercial traits in plantation forestry.