Perilla AP2 Gene Family PfWRI1 Promotes Oil Accumulation in Plant Seeds
AP2 transcription factors belong to the AP2/ERF superfamily and are involved in the regula-tion of various biological processes in plant growth and development,as well as in response to biotic and abiotic stresses.However,studies on the AP2 transcription factor family of Perilla frutescens have not been reported.In this study,totally 18 AP2 family members were identified from the Perilla frutescens ge-nome and analyzed for gene structure,conserved motifs,and cis-acting elements using bioinformatics.WRINKLED1(WRI1)is a key regulator of lipid biosynthesis in many plant species and plays an impor-tant role in the regulation of lipid synthesis.Sequence comparison revealed that one member of WRI1 is highly homologous to AtWRI1 and contains two conserved AP2 domains,named PfWRI1.The expression levels of PfAP2 family genes were analyzed in different tissues of Perilla frutescens and at different stages of seed development in conjunction with the transcriptome data,and the results showed that PfWRI1 is highly expressed only in the seeds of Perilla frutescens,suggesting that PfWRI1 may be related to the de-velopmental process of the seeds.The overexpression vector of plant pCAMBIA1303-PfWRI1 was con-structed,and wild-type(Col)and mutant(wri1-1)Arabidopsis thaliana were transformed by Agrobacte-rium tumefaciens to obtain overexpression and complementation lines,respectively.The results showed that the expression of P fWRI1 led to an increase in oil content of Arabidopsis seeds by 8.90%-13.57%compared with Col,and promoted the accumulation of oleic acid(C18:1)and linoleic acid(18:2)and reduced the accumulation of palmitic acid(C16:0),arachidonic acid(C20:0),and cis-11-Eicosenoic acid(C20:1)in transgenic Arabidopsis seeds.In addition,PfWRI1 gene expression increased the ex-pression of glycolysis and fatty acid biosynthesis-related genes AtPKP-α,AtPKP-β1,AtBCCP2,AtSUS2,and AtLIP1.Taken together,PfWRI1 may promote lipid accumulation by increasing unsaturated fatty acid content through interaction with the above genes.