Poster: Cell Walls
Abs #
1266: Analysis of CesA genes expressed in developing cotton fiber by real time RT-PCR
All of the higher plants that have been examined to date have multiple members of the CesA gene family, the gene that encodes the catalytic subunit of cellulose synthase. Products of the CesA gene family are likely to function as cellulose synthase isoforms, however their roles in plant development are not well understood. Cotton fibers are long, unicellular seed trichomes whose secondary cell walls consist of almost pure cellulose. As a result, cotton fiber is known to be an excellent model system for studying cellulose biosynthesis (Kim and Triplett, 2001). Although the first two characterized higher plant CesA genes were from developing cotton fiber (Pear et al, 1996), the total number of cotton fiber CesAs expressed during each stage of fiber development was unknown. Using primer pairs designed from Gossyium hirsutum fiber ESTs that contained CesA motifs, we analyzed the expression of 10 different CesAs throughout fiber development and in other cotton tissues using quantitative real time RT-PCR. Our results show that three CesA genes and a Ces-like gene (Csl) are expressed during the cell elongation stage of fiber development. Three additional CesA genes that are abundantly expressed during secondary wall formation are also expressed at low levels during cell elongation. At least three other CesA genes are expressed in fiber and appear to be expressed at both stages of development. All tested CesA genes were expressed in other tissues in addition to fiber, and their expression levels were also developmentally regulated during the formation of leaf, stem, and root.
Kim & Triplett (2001) Plant Physiol 127: 1361-1366
Pear et al. (1996) Proc Natl Acad Sci USA 93: 12637-12642
