The olive DGAT2 gene is developmentally regulated and shares overlapping but distinct expression patterns with DGAT1
Open Access
- 24 September 2010
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Experimental Botany
- Vol. 62 (2), 521-532
- https://doi.org/10.1093/jxb/erq286
Abstract
Diacylglycerol acyltransferases (DGATs) catalyse the final step of the triacylglycerol (TAG) biosynthesis of the Kennedy pathway. Two major gene families have been shown to encode DGATs, DGAT1 (type-1) and DGAT2 (type-2). Both genes encode membrane-bound proteins, with no sequence homology to each other. In this study, the molecular cloning and characterization of a type-2 DGAT cDNA from olive is presented. Southern blot analysis showed that OeDGAT2 is represented by a single copy in the olive genome. Comparative transcriptional analysis revealed that DGAT1 and DGAT2 are developmentally regulated and share an overall overlapping but distinct transcription pattern in various tissues during vegetative growth. DGAT2 is highly expressed in mature or senescing olive tissues. In flowers, the expression of DGAT1 was almost undetectable, while DGAT2 transcripts accumulated at the later stages of both anther and ovary development. Differential gene regulation was also detected in the seed and mesocarp, two drupe compartments that largely differ in their functional roles and mode of lipid accumulation. DGAT1 appears to contribute for most of the TAG deposition in seeds, whereas, in the mesocarp, both DGAT1 and DGAT2 share an overlapping expression pattern. During the last stages of mesocarp growth, when TAGs are still accumulating, strong up-regulation of DGAT2 but a marked decline of DGAT1 transcript levels were detected. The present results show overlapping gene expression for olive DGATs during mesocarp growth, with a more prominent implication of DGAT2 in floral bud development and fruit ripening.Keywords
This publication has 56 references indexed in Scilit:
- DGAT1andPDAT1Acyltransferases Have Overlapping Functions inArabidopsisTriacylglycerol Biosynthesis and Are Essential for Normal Pollen and Seed DevelopmentTHE PLANT CELL ONLINE, 2009
- Oil Bodies and Oleosins in Physcomitrella Possess Characteristics Representative of Early Trends in EvolutionPlant Physiology, 2009
- Lipid droplets at a glanceJournal of Cell Science, 2009
- The Endoplasmic Reticulum Enzyme DGAT2 Is Found in Mitochondria-associated Membranes and Has a Mitochondrial Targeting Signal That Promotes Its Association with MitochondriaJournal of Biological Chemistry, 2009
- Metabolic engineering of hydroxy fatty acid production in plants: RcDGAT2 drives dramatic increases in ricinoleate levels in seed oilPlant Biotechnology Journal, 2008
- Metabolic control analysis is helpful for informed genetic manipulation of oilseed rape (Brassica napus) to increase seed oil contentJournal of Experimental Botany, 2008
- The utilization and desaturation of oleate and linoleate during glycerolipid biosynthesis in olive (Olea europaea L.) callus culturesJournal of Experimental Botany, 2008
- Tung Tree DGAT1 and DGAT2 Have Nonredundant Functions in Triacylglycerol Biosynthesis and Are Localized to Different Subdomains of the Endoplasmic ReticulumTHE PLANT CELL ONLINE, 2006
- Cytosolic Triacylglycerol Biosynthetic Pathway in Oilseeds. Molecular Cloning and Expression of Peanut Cytosolic Diacylglycerol AcyltransferasePlant Physiology, 2006
- Diacylglycerol acyltransferase in maturing safflower seeds: its influences on the fatty acid composition of triacylglycerol and on the rate of triacylglycerol synthesisBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1988