Functional Analysis of Arabidopsis Sucrose Transporters

Ward, John M.

University of Minnesota

关键词: Plant Sucrose Transporter, Biochemistry, Electrophysiology;    Specificity;    Genes;    Carbohydrates;    59 Basic Biological Sciences;   

DOI  :  10.2172/950496
RP-ID  :  DOE-ER15414-1
RP-ID  :  FG02-03ER15414
RP-ID  :  950496

美国|英语

来源: UNT Digital Library

【 摘 要 】

Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.