Pan, Irvin L. , Irish, Vivian F. .
Functional analysis of a MADS box gene involved in tomato fruit development.
Carotenoids are isoprenoid derived compounds that are required for photoprotective functions during photosynthesis and pigmentation in plants. During tomato fruit ripening, one metabolic change that occurs is the accumulation of carotenoids that give tomatoes their distinctive color. Due to their nutritional importance and antioxidant properties, carotenoids have been a target for crop improvement. Although the carotenoid biosynthetic pathway has been well characterized, the regulation of this pathway is less well understood. We have identified a tomato MADS box transcription factor, ML1, which appears to play a fundamentally important role in regulating the carotenoid biosynthetic pathway. ML1 is expressed during late stages of flower development, early fruit development, and is down-regulated at later stages of fruit maturation. We have generated RNAi induced loss-of-function lines for ML1 and they produce tomato fruit that have a distinct orange color phenotype. Analyses of these fruit show that they produce higher levels of several carotenoids and this phenotype is associated with the transcriptional upregulation of several carotenoid biosynthetic genes. Our data suggest that ML1, unlike other ripening-related genes that affect all aspects of ripening, may be specifically and coordinately regulating transcription of carotenoid biosynthetic genes during fruit development. Currently we are further characterizing the ML1 loss-of-function phenotype, as well as assaying the effects of overexpression of ML1, and progress on these analyses will be presented.
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1 - Yale University, Molecular, Cellular, and Developmental Biology, P.O. Box 208104, New Haven, Connecticut, 06520, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Boulevard B/Hilton
Date: Wednesday, July 11th, 2007
Time: 3:00 PM