Project Number: 6435-41000-087-06
Project Type: Specific Cooperative Agreement

Start Date: Aug 01, 2007
End Date: Aug 01, 2009

Objective:
To determine the cell biological properties of enzymes involved in tung oil production. Specifically, sophisticated microscopic techniques will be used to investigate the subcellular location, topological orientation and dynamic properties of these enzymes in cellular membranes. This information will substantially increase our basic understanding of how these enzymes are organized in plant cells, and will aid in the selection of genes necessary for the future design of crops plants producing value-added industrial oils.

Approach:
Tung oil is a high-value industrial oil produced in the seeds of the tung tree, and our long term goal is to elucidate the molecular processes that are involved in and to determine the minimal necessary enzyme sets that are required for the production of tung oil. This information will aid in the development of enzymatic methods to convert low-cost vegetable oils into value-added drying oils. Our current studies focus on the characterization of glycerol-3-phosphate acyltransferase enzymes, isoforms 8 and 9 (GPAT8, GPAT9) (for additional information please see CRIS Project Plan file 306Dyer6435-41000-083-00DPost-PP). We have recently cloned the genes encoding these enzymes from tung, and experiments will be conducted to characterize the cellular properties of the respective enzymes. Much work has been previously completed. Each DNA sequence was modified to allow for detection of the expressed proteins in plant cells. These cells lines were used to determine the subcellular location, membrane topology, and dynamic properties of each protein. In FY 2009, complete characterization of GPAT8 and GPAT9 will be achieved will be achieved by observing the (immuno)staining patterns using a variety of microscopic techniques, including epifluorescence, confocal laser-scanning, fluorescence lifetime imaging microscopy, and fluorescence resonance energy transfer. Also in FY 2009, preliminary targeting and membrane topology experiments will be conducted for select lysophosphatidic acid acyltransferase (LPAT) enzymes from tung. Collectively, these studies represent an important component of our overall strategy to characterize the functional and cellular properties of these enzymes, and will help keep us at the cutting edge of research focused on the production of high-value oils in crop plants.