Perilla frutescens (L.) Britt. is a characteristic oil crop rich in polyunsaturated fatty acids, particularly α-linolenic acid, which has important development and utilization value. The Dof transcription factor is one of the plant-specific transcription factor families, which is widely involved in important biological processes such as plant growth, development, and metabolic regulation. In order to explore the key Dof transcription factors involved in the oil biosynthesis and systematically analyze their regulatory mechanisms of P. frutescens seeds, a total of 56 PfDof gene family members were identified from the genome and transcriptome data of P. frutescens and classified into four subfamilies according to sequence characteristics. All PfDofs contained highly conserved C₂-C₂ zinc finger domains, with gene duplication being the primary mechanism driving their evolution and expansion. Genes within the same subgroup exhibited similar gene structures and conserved motifs. The 56 PfDofs were predicted as unstable hydrophilic proteins, with α-helixes and random coils as their predominant structural components. The RNA-seq results revealed that 11 PfDofs exhibited differential expression during different developmental stages of P. frutescens seeds. RT-qPCR was performed to further validate the expression patterns of these 11 members across various tissue samples (root, stem, leaf, and flower) of P. frutescens and at different developmental stages of its seeds. The results showed that PfDof29 exhibited the highest expression level in seeds, which was consistent with the transcriptome data. Subcellular localization studies demonstrated that PfDof29 was localized to the nucleus and had a transcriptional activation activity. Overexpression of PfDof29 in Nicotiana tabacum resulted in a significant increase in total oil content of tobacco leaves, accompanied by reductions in starch and soluble sugar content, while the protein content remained unchanged. Additionally, the metabolic balance between saturated and unsaturated fatty acids in the transgenic tobacco leaves was altered, with a significant increase in α-linolenic acid content. The expression levels of the fatty acid desaturase genes NtFAD2, NtFAD3, and NtFAD8 were significantly upregulated. A yeast one-hybrid assay revealed that PfDof29 could directly bind to the promoter region of PfFAD8, thereby regulating its expression. This study provides an initial understanding of the regulatory mechanisms of PfDof transcription factors in the synthesis and accumulation of oil in P. frutescens. These findings offer new insights into the enhancement of oil content and quality of P. frutescens seeds.
Transcription Factors/physiology* ; Perilla frutescens/metabolism* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant ; alpha-Linolenic Acid/biosynthesis* ; Lipids/biosynthesis* ; Seeds/genetics*

Alpha-linolenic acid(ALA, C18:3delta9,12,15 ) is an essential fatty acid which has many sanitary functions to human. However, its contents in diets are often not enough. In plants, omega-3 fatty acid desaturases(FAD) catalyze linoleic acid(LA, C18:2delta9,12) into ALA. The seed oil of Glycine max contains high level of ALA. To investigate the functions of Glycine max omega-3FAD, the cDNA of GmFAD3 C was amplified by RT-PCR from immature seeds, then cloned into the shuttle expression vector p416 to generate the recombinant vector p4GFAD3C. The resulting vector was transformed into Saccharomyces cerevisiae K601 throuth LiAc method. The positive clones were screened on the CM(Ura-) medium and identified by PCR, and then cultured in CM (Ura-) liquid medium with exogenous LA in 20 degrees C for three days. The intracellular fatty acid composition of the engineering strain Kp416 and Kp4GFAD3C was analyzed by gas chromatography (GC). A novel peak in strain Kp4GFAD3C was detected,which was not detectable in control, Comparison of the retention times of the newly yielded peak with that of authentic standard indicated that the fatty acid is ALA. The content of ALA reached to 3.1% of the total fatty acid in recombinant strain, the content of LA correspondingly decreased from 22% to 16.2% by contrast. It was suggested that the protein encoded by GmFAD3 C can specifically catalyze 18 carbon PUFA substrate of LA into ALA by taking off hydrogen atoms at delta15 location. In this study, we expressed a Glycine max omega-3 fatty acid desaturase gene in S. cerevisiae; An efficient and economical yeast expressing system(K601-p416 system) which is suitable for the expression of FAD was built.
Chromatography, Gas ; Cloning, Molecular ; Fatty Acid Desaturases ; biosynthesis ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism ; Soybeans ; enzymology ; genetics ; alpha-Linolenic Acid ; analysis ; biosynthesis ; genetics

OBJECTIVE[corrected] To investigate the effect of peroxisome proliferator-activated receptors (PPARs) activators on plasminogen activator inhibitor type-1 (PAI-1) expression in human umbilical vein endothelial cells and the possible mechanism.

METHODSHuman umbilical vein endothelial cells (HUVECs) were obtained from normal fetus, and cultured conventionally. Then the HUVECs were exposed to test agents (linolenic acid, linoleic acid, oleic acid, stearic acid and prostaglandin J2 respectively) in varying concentrations with fresh media. RT-PCR and ELISA were applied to determine the expression of PPARs and PAI-1 in HUVECs.

RESULTSPPAR alpha, PPAR beta and PPAR gamma mRNA were detected by using RT-PCR in HUVECs. Treatment of HUVECs with PPARalpha and PPAR gamma activators--linolenic acid, linoleic acid, oleic acid and prostaglandin J2 respectively, but not with stearic acid could augment PAI-1 mRNA expression and protein secretion in a concentration-dependent manner. However, the mRNA expressions of 3 subclasses of PPAR with their activators in HUVECs were not changed compared with controls.

CONCLUSIONHUVECs express PPARs. PPARs activators may increase PAI-1 expression in ECs, but the underlying mechanism remains unclear. Although PPARs expression was not enhanced after stimulated by their activators in ECs, the role of functionally active PPARs in regulating PAI-1 expression in ECs needs to be further investigated by using transient gene transfection assay.

Cells, Cultured ; Endothelium, Vascular ; cytology ; metabolism ; Fatty Acids ; pharmacology ; Fetus ; Humans ; Linoleic Acid ; pharmacology ; Plasminogen Activator Inhibitor 1 ; biosynthesis ; genetics ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; RNA, Messenger ; genetics ; Receptors, Cytoplasmic and Nuclear ; biosynthesis ; genetics ; Transcription Factors ; biosynthesis ; genetics ; Umbilical Veins ; cytology ; metabolism ; alpha-Linolenic Acid ; pharmacology