Abstract：
Glycerol3phosphate acyltransferase (GPAT) is a key enzyme in the synthesis of TAG. The objective of this study was to screen and identify the glyceryl triphosphate acyltransferase 9 gene from perilla and reveal this protein characteristics and functions. The 〖STBX〗〖WTBX〗Pfgpat9〖WTBZ〗〖STBZ〗 gene fragment was screened from the perilla transcriptome database, with the preferred variety ‘Jinzisu 1’ as material, the fulllength ORF sequence was cloned by RTPCR. It was named Pfgpat9. The tissue expression characteristics of Pfgpat9 gene was analyzed by realtime PCR in root, stem, leaf, flower and seeds at different developmental stages (10, 20, 30, 40 days after flowering) of perilla. The complete ORF sequence of Pfgpat9 gene was ligated into the yeast expression vector pYES2.0 by double digestion, and the recombinant plasmid was transformed into the wild type yeast strain INVSc1 and the GPAT deficient gat1 yeast strain. The results showed that the Pfgpat9 gene ORF was 1 116 bp, encoding a total of 371 amino acids. The theoretical isoelectric point (pI) was 8.96, the instability coefficient was 46.67, and the hydrophilicity coefficient was -0.108. These results showed that PfGPAT9 protein was a hydrophilic and labile protein. The Pfgpat9 gene had a typical GPAT9 functional domain and contained three typical transmembrane helix regions. Multiple sequence alignment analysis showed that the PfGPAT9 protein was closely related to Olea europaea, Camellia sinensis and Helianthus annuus GPAT9 protein. qRTPCR analysis showed that Pfgpat9 gene was expressed in different tissues of perilla, and the expression level increased firstly and then decreased at different stages of seed development, and reached the highest level at 20 days after flowering. The yeast transformation results indicated that the total lipid content of Pfgpat9 genetransformed wild type yeast and Pfgpat9 genedeficient yeast were increased, and the C16∶0, C16∶1 were all increased. The study indicated that Pfgpat9 gene plays an important role in the oil synthesis and accumulation of perilla seeds, and can provide genetic element and technology system for creating other ordinary oil crop new lines.
