Gene discovery in the wood-forming tissues of poplar: Analysis of 5,692 expressed sequence tags

• DOI: 10.1073/pnas.95.22.13330
• Publication Date: 2002-07-26T14:42:40Z
• Authors: Fredrik Sterky; Sharon Regan; Jan Karlsson; Magnus Hertzberg; Antje Rohde; Anders Holmberg; Bahram Amini; Rupali Bhalerao; Magnus Larsson; Raimundo Villarroel; Marc Van Montagu; Göran Sandberg; Olof Olsson; Tuula T. Teeri; Wout Boerjan; Petter Gustafsson; Mathias Uhlén; Björn Sundberg; Joakim Lundeberg
• Keywords: 580; Expressed Sequence Tags; 2. Zero hunger; 0303 health sciences; DNA, Complementary; Molecular Sequence Data; Arabidopsis; Gene Expression; Oryza; Brassica; 15. Life on land; Genes, Plant; Zea mays; Enzymes; Trees; 03 medical and health sciences; cambium/forestry/functional genomics/xylem/xylogenesis; Cloning, Molecular; Forest Sciences; Crosses, Genetic; Gene Library; Plant Proteins

A rapidly growing area of genome research is the generation of expressed sequence tags (ESTs) in which large numbers of randomly selected cDNA clones are partially sequenced. The collection of ESTs reflects the level and complexity of gene expression in the sampled tissue. To date, the majority of plant ESTs are from nonwoody plants such as Arabidopsis , Brassica , maize, and rice. Here, we present a large-scale production of ESTs from the wood-forming tissues of two poplars, Populus tremula L. × tremuloides Michx. and Populus trichocarpa ‘Trichobel.’ The 5,692 ESTs analyzed represented a total of 3,719 unique transcripts for the two cDNA libraries. Putative functions could be assigned to 2,245 of these transcripts that corresponded to 820 protein functions. Of specific interest to forest biotechnology are the 4% of ESTs involved in various processes of cell wall formation, such as lignin and cellulose synthesis, 5% similar to developmental regulators and members of known signal transduction pathways, and 2% involved in hormone biosynthesis. An additional 12% of the ESTs showed no significant similarity to any other DNA or protein sequences in existing databases. The absence of these sequences from public databases may indicate a specific role for these proteins in wood formation. The cDNA libraries and the accompanying database are valuable resources for forest research directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.