Author
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BUSH, DANIEL |
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Submitted to: Current Opinion in Plant Biology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/1/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Plant leaves capture light energy and transform that energy into a biologically useful form in the process called photosynthesis. The primary product of photosynthesis is sucrose. Generally, 50 to 80 percent of the sucrose synthesized during photosynthesis is transported from the leaf to supply many of the edible parts of the plant such as fruits, grains, and tubers. Alterations in the transport process are known to significantly affect crop productivity. Our understanding of plant sugar transporters has advanced considerably over the last ten years. Initially, purified membrane vesicles and imposed proton electrochemical potential differences were used to describe the basic transport properties and bioenergetics of several transporters. Then, the first sugar transporter genes were cloned. With cDNA clones in hand, researchers have used transgenic plants and heterologous expression to investigate every aspect of transporter biology, ranging from dissecting the physiology of a given transporter to identifying the amino acid residues that contribute to the transport reaction. This review, which describes the recent advances in dissecting the physiological and molecular complexity of plant sugar transporters, is a valuable reference for agriculture scientists in universities and industry for formulating new approaches to modify crop yeild and nutritional value. Technical Abstract: One of the defining features of multicellular growth is the need to partition resources among organ systems that specialize in diverse biological processes. The leaf is the principle site of energy and carbon acquisition while other organ systems carry out additional essential activities, such as water and ion uptake in roots, or reproduction in flowers. Many of these organs are composed of nonphotosynthetic tissues systems that must import sugars to support growth and development. The transport and allocation of sugars between photosynthetic leaf tissue and import-dependent tissues are known as assimilate partitioning, and sugar transporters in both tissue systems play key roles in mediating this complex process. Our understanding of plant sugar transporters has advanced considerably over the last ten years. Initially, purified membrane vesicles and imposed proton electrochemcial potential differences were used to describe the basic transport properties and bioenergetics of several transporters. Then, the first sugar transporter genes were cloned. With cDNA clones in hand, researchers have used transgenic plants and heterologous expression to investigate every aspect of transporter biology, ranging from dissecting the physiology of a given transporter to identifying the amino acid residues that contribute to the transport reaction. This review described recent advances in dissecting the physiological and molecular complexity of plant sugar transporters. |
