Lipid Metabolism in Cotton Fiber Cells
Cotton fibers are trichomes that arise from differentiation of ovular epidermal cells. Development of these cells progresses through stages of elongation, secondary wall deposition and maturation (Basra and Malik,1984, Int Rev Cytol 89:65-109) forming extremely long single cells, that extend perpendicularly above the surface of the ovule (Ramsey and Berlin,1976, Am J Botany 63(6):868-876). This period of rapid cellular elongation requires substantial synthesis of lipids necessary for the formation of the vacuolar and plasma membranes. Hence lipid metabolism may be an important factor in fiber development. Plant membrane lipids consist mainly of glycerolipids. Structural membrane glycerolipids contain the common fatty acids, 16-carbon or 18-carbon fatty acids, most of which are polyunsaturated, and the composition of these lipids is critical for growth and development (Wallis and Browse, 2002, Prog. Lipid Res., 41:254-278). Our aim is to evaluate the fatty acid composition as well as the class and species of complex lipids in cotton fiber at different stages of development, which will be critical in understanding the role of membrane biogenesis in fiber development.
Genomic information is a valuable resource for understanding different cellular processes in any organism, including those involved in their growth and development. More than 50,000 expressed sequence tags (ESTS) from Gossypium sp. fiber cells have been sequenced by several laboratories (predominantly Brookhaven National Laboratory and Clemson University Genomics Institute) and compiled by The Institute for Genomic Research (at www.TIGR.org). Most all of these are derived from cotton fibers at 6 or 7-10 days post anthesis (dpa), during the stage of rapid cell elongation. We have cataloged the profiles of ESTs for enzymes involved in lipid metabolism during this stage of cotton fiber development. These data when compared to our metabolite profiles, allows us to predict which lipid metabolic pathways are operating during the stages of rapid cell elongation and secondary wall deposition.
Genomic information is a valuable resource for understanding different cellular processes in any organism, including those involved in their growth and development. More than 50,000 expressed sequence tags (ESTS) from Gossypium sp. fiber cells have been sequenced by several laboratories (predominantly Brookhaven National Laboratory and Clemson University Genomics Institute) and compiled by The Institute for Genomic Research (at www.TIGR.org). Most all of these are derived from cotton fibers at 6 or 7-10 days post anthesis (dpa), during the stage of rapid cell elongation. We have cataloged the profiles of ESTs for enzymes involved in lipid metabolism during this stage of cotton fiber development. These data when compared to our metabolite profiles, allows us to predict which lipid metabolic pathways are operating during the stages of rapid cell elongation and secondary wall deposition.

