Expression Pattern And Function Study Of Fatty Acyl Thioesterase And Palmitoyl Acyl Transferase Family In Arabidopsis Thaliana

Acyl carrier protein (ACP) thioesterases play essential roles in chain terminating de novofatty acid synthesis. There are two distinct but related ACP thioesterase classes in higherplants, termed FatA and FatB, FatA-type fulfills a fundamental role in the export of the C18fatty acid moieties that will be used to synthesize most plant glycerolipids. However, little isknown about the plant function of FatA family containing two members (AT4G13050andAT3G25110). We characterized FatA family by real time PCR and investigated fatty acidcompositions of seeds mutant with a T-DNA insertion in the FatA gene AT4G13050, termedSalk-111046C. The T-DNA insertions were located178bp upstream of the start of codon andhomozygous line for the insertion was obtained. Levels of all fatty acid compositions areincreased compared with those of wild type except20:0fatty acid.Palmitoylation is a reversible posttranslation addition of palmitate to cysteineresidues in proteins through a thioester bond by a DHHC family ofpalmitoyltransferases(PATs) involved in cellular signaling, membrane trafficking, synaptictransmission. There are20genes containing DHHC domain predicted to encode putativepalmitoyltransferases in Arabidopsis thaliana genome. However, little is kown aboutArabidopsis putative PATs. Here we present an overview of the putative PAT genes inArabidopsis thaliana focusing on their phylogeny and expression profiles in different tissuesand under stresses. Besides conserved DHHC domain, the identity of their cDNA sequenceswas from30%to60%.Temprospatial expression profile of each putative gene of the entirePAT family showed that nineteen of twenty putative PAT members differently expressed inflowers, leaves, stems, roots, seedlings, young and old siliques except At2g40990, in addition,expression of many Arabidopsis putative PATs were changed under different stress treatments.