Tung tree (Vernicia fordii) is an important woody oil tree. Tung tree seeds
contain 50-60% oil with approximately 80 mole ?-eleostearic acid (9 cis, 11
trans, 13 trans octadecatrienoic acid). Fatty acid synthesis is catalyzed by
the concerted action of acetyl-CoA carboxylase and fatty acid synthase, a
multienzyme complex including ?-ketoacyl-acyl-carrier-protein synthase
(KAS). Little is known about KAS in tung tree. The objective of this study
was to clone KAS genes and analyze their expression profiles in tung tree. A
full-length cDNA encoding KAS III and a partial cDNA encoding KAS II were
isolated from tung tree by PCR cloning using degenerate primers and rapid
amplification of cDNA ends system. The full-length cDNA of VfKAS III was 1881
bp in length with an open reading frame of 1212 bp. VfKAS III genomic DNA was
also isolated and sequenced, which contained 8 exons in 5403 bp length. The
deduced VfKAS III protein shared approximately 80% identity with homologous
KAS IIIs from other plants. Quantitative PCR analysis revealed that KAS II
and KAS III were expressed in all of the tissues and organs tested but
exhibited different expression patterns in tung tree. The expression levels
of KAS II in young tissues were much lower than those in mature tissues,
whereas the highest expression levels of KAS III were observed in young stem
and young leaf. These results should facilitate further studies on the
regulation of tung oil biosynthesis by KAS in tung tree.
Tung Tree (Vernicia fordii) Genome Provides A Resource for Understanding Genome Evolution and Improved Oil Production
