| Abstract Detail
Metabolic Engineering Khodakovskaya, Mariya [1], Hung, Chiu-Yeh [2], Perera, Imara [2], Boss, Wendy [2], Brown, Christopher [3], Winter Sederoff, Heike [2]. Improved drought tolerance, nutraceutical value and biomass production of tomatoes by overexpression of inositol polyphosphate 5-phosphatase. Inositol 1,4,5-trisphosphate (InsP3) is a second messenger that increases rapidly in response to many stimuli in plants. To elucidate the role of InsP3 metabolism on growth, development, and response to abiotic stress in tomato plants, we reduced the level of InsP3 (cv. Micro-Tom) by expressing the human type I inositolpolyphosphate 5-phosphatase (InsP 5-ptase) gene. Independent transgenic lines expressing the InsP 5-ptase, had only 10-39% of the InsP3 concentration of wild type and vector control plants and showed dramatic phenotypic differences. Compared to the wild type plants, the InsP 5-ptase expressing tomato lines have increased total biomass. The shoots have more branches, more of leaves per branch, and increased leaf thickness and leaf area caused by a four fold increase in cell size compared to wild type and vector control plants. The tomato plants expressing InsP 5-ptase were more drought tolerant and survived longer than the controls plants when water was withheld. At the metabolic level, concentrations of carbohydrates and natural products in fruits were modulated. Fructose and glucose concentrations were three times higher in InsP 5-ptase tomato fruits compared with control fruits. HPLC analysis of carotenoids in control and transgenic fruits showed that the InsP 5-ptase expressing fruits accumulated several fold greater concentrations of lycopene, but similar amounts of carotene. Comparative transcript profiling identified an over-expression of genes involved in ethylene-mediated signal transduction in leaves of the InsP 5-ptase–expressing tomato seedlings. Our results demonstrate a potential new strategy for improving crop plants. (Supported by NASA).
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1 - North Carolina State University, Plant Biology, 4218 Gardner Hall, Raleigh, NC, 27695, USA
2 - North Carolina State University, Plant Biology
3 - North Carolina State University, Plant Biology, Kenan Institute for Engineering, Technology & Science
Keywords:
tomato
stress tolerance
transformation
leaf morphology
genome profiling.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P43003
Abstract ID:315 |
