Tree Physiology Advance Access originally published online on August 10, 2009
Tree Physiology 2009 29(10):1299-1305; doi:10.1093/treephys/tpp054
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Cloning and functional characterization of an acyl-acyl carrier protein thioesterase (JcFATB1) from Jatropha curcas
1 Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
2 Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
3 Corresponding author (wugj{at}scbg.ac.cn)
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Abstract |
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A full-length cDNA of an acyl-acyl carrier protein (ACP) thioesterase (TE) (EC 3.1.2.14 [EC] ), named JcFATB1, was isolated from the woody oil plant Jatropha curcas L. The deduced amino acid sequence of the cDNA shares about 78% identity with FATB TEs, but only about 33% identity with FATA TEs from other plants. The deduced sequence also contains two essential residues (H317 and C352) for TE catalytic activity and a putative chloroplast transit peptide at the N-terminal. Southern blot analysis revealed that a single copy of JcFATB1 is present in the J. curcas genome, and semi-quantitative PCR analysis showed that JcFATB1 was expressed in all tissues that were examined, most strongly in seeds, in which its expression peaked in late developmental stages. Seed-specific overexpression of the JcFATB1 cDNA in Arabidopsis resulted in increased levels of saturated fatty acids, especially palmitate, and in reduced levels of unsaturated fatty acids. The findings suggest that JcFATB1 from this woody oil plant can function as a saturated acyl-ACP TE and could potentially modify the seed oil of J. curcas to increase its levels of palmitate.
Keywords: fatty acid, palmitate
Received March 31, 2009; Accepted July 1, 2009