Liu, Zhenlan , Adams, Keith .
Subfunctionalization of genes duplicated by polyploidy in response to environmental stress.
Allopolyploidy has been a prominent speciation mechanism and a recurrent process during plant evolution that has contributed greatly to the large number of duplicated genes in plant genomes. Polyploidy often leads to changes in genome organization and gene expression. The expression of genes duplicated by polyploidy (homeologs) can be partitioned between the duplicates so that one copy is expressed and functions only in some organs and the other copy is expressed only in other organs, indicative of subfunctionalization. To determine how homeologous gene expression patterns change during organ development and in response to abiotic stress conditions we have examined expression of the alcohol dehydrogenase gene AdhA in allopolyploid cotton (Gossypium hirsutum). Expression ratios of the two homeologs vary considerably during the development of seedling and boll organs. Abiotic stress treatments, including cold and water submersion, altered homeologous gene expression. Most notably, only one copy is expressed during a water submersion treatment and only the other copy is expressed during cold stress. These results indicate that subfunctionalization of genes duplicated by polyploidy has occurred in response to abiotic stress conditions. Partitioning of duplicate gene expression and function in response to environmental stress leads to duplicate gene retention and may help explain the presence of large numbers of gene duplicates in plant genomes.
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1 - University of British Columbia, Botanical Garden, Centre for Plant Research, and Botany Department, 6270 University Blvd, Vancouver, BC, V6T1Z4, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Huron/Hilton
Date: Monday, July 9th, 2007
Time: 1:45 PM