RESEARCH ARTICLE

Journal of Oil Palm Research Vol. 22 (2) August 2010, p. 803-813

FUNCTIONAL ANALYSIS OF OIL PALM PALMITOYL-ACP THIOESTERASE (fatB) GENE VIA DOWN-REGULATION IN A MODEL PLANT: Arabidopsis thaliana

AHMAD PARVEEZ Ghulam Kadir ; ABRIZAH Othman ; NURHAFIZAH Ramin ; BAHARIAH Bohari

ABSTRACT

Isolation of genes from the oil palm (Elaeis guineensis) has been routinely carried out to genetically alter the fatty acid content of palm oil to produce novel fatty acids and other metabolites. This study evaluated the function of an oil palm palmitoyl-ACP thioesterase (FatB) gene in the model plant Arabidopsis thaliana. Arabidopsis thaliana was transformed via the ‘floral-dip’ transformation method with either the gusA reporter gene (pCAMBIA 3301), an antisense palmitoyl-ACP thioesterase gene (pCB302-AT2), or the sense palmitoyl-ACP thioesterase gene (pCB302-AT1), together with the bar (Basta-resistant) selectable marker gene. Transformed seeds were selected by growing them on wet compost containing Basta. Bastaresistant plants were subjected to PCR and GUS analyses to prove the integration of the transgenes and their expression. Fatty acid composition of the transgenic seeds were analysed using gas chromatography. It was observed that the amount of palmitic acid (C16:0) in the sense transgenic seeds increased to 11.78 mol% compared to 8.91 mol% in the wild type control plants. Fatty acid analysis of the antisense transgenic seeds revealed that the amount of C16:0 in these lines decreased slightly from 8.91 mol% to 8.13 mol%. The results revealed the expected function of the oil palm palmitoyl-ACP thioesterase gene. Furthermore, this study also demonstrated the ability to test functionality of oil palm genes (from a monocotyledon) in a dicotyledonous plant, Arabidopsis thaliana.

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* Malaysian Palm Oil Board,
P. O. Box 10620,
50720 Kuala Lumpur,
Malaysia.
E-mail: parveez@mpob.gov.my