Tree peony transcription factor PrWRI1 enhances seed oil accumulation.

BACKGROUND: WRINKLED1 (WRI1) encodes a transcription factor, belonging to the APETALA2 (AP2) family, and plays a key role in regulating plant oil biosynthesis. As a newly woody oil crop, tree peony (Paeonia rockii) was notable for the abundant unsaturated fatty acids in its seed oil. However, the role of WRI1 during the accumulation of P. rockii seeds oil remains largely unknown. RESULTS: In this study, a new member of the WRI1 family was isolated from P. rockii and was named PrWRI1. The ORF of PrWRI1 consisted of 1269 nucleotides, encoding a putative protein of 422 amino acids, and was highly expressed in immature seeds. Subcellular localization analysis in onion inner epidermal cells showed that PrWRI1 was located at the nucleolus. Ectopic overexpression of PrWRI1 could significantly increase the total fatty acid content in Nicotiana benthamiana leaf tissue and even PUFAs in transgenic Arabidopsis thaliana seeds. Furthermore, the transcript levels of most genes related to fatty acids (FA) synthesis and triacylglycerol (TAG) assembly were also up-regulated in transgenic Arabidopsis seeds. CONCLUSIONS: Together, PrWRI1 could push carbon flow to FA biosynthesis and further enhance the TAG amount in seeds with a high proportion of PUFAs.

Phytochemical components and bioactivities of novel medicinal food - Peony roots.

Peony as an important medicinal material is widely cultivated in China, which is one of the natural distribution centers of wild peony species. So far, however, there has not been a systematic study of the roots from China's wild peonies. In this study, the total phenolic (TPC), total flavonoid (TFC), other secondary metabolites, and microelement content, as well as the antioxidant, antibacterial, anticholinesterase, and antitumor activities of peony roots from 15 species and 2 subspecies were measured. Thirteen secondary metabolites were detected, with Paeoniflorin and Paeonol being the highest content bio-activities compounds. Additionally, the peony roots had a significant antioxidant activities and bacteriostatic effect against Gram-positive bacteria, with MIC varying from 0.063 to 1 mg/mL. P. anomala subsp. veitchii and P. lactiflora showed outstanding anticholinesterase capacities and cytotoxic activities. Taken together, the data presented here provide new insights into both the medicinal and edible potential of roots from wild peony species.

Phenotypic Characteristics and Fatty Acid Composition of Seeds from Different Herbaceous Peony Species Native to China.

Herbaceous peony has been widely cultivated in China due to its substantial ornamental and medicinal value. In the present study, the phenotypic characteristics, total fatty acid (FA) content, and nine FA compositions of herbaceous peony seeds from 14 populations belonging to six species and one subspecies were determined by normal test and gas chromatography/mass spectrometry (GC/MS). The results showed that the phenotypic characteristics of seeds varied dramatically among species. The concentrations of five major FAs in seed oils were as follows: linoleic acid (173.95-236.51 µg/mg), linolenic acid (227.82-302.71 µg/mg), oleic acid (135.32-208.81 µg/mg), stearic acid (6.52-11.7 µg/mg), and palmitic acid (30.67-47.64 µg/mg). Correlation analysis demonstrated that oleic acid had the highest partial correlation coefficient with total FAs and might be applied to develop a model of phenotypic characteristics. FAs were significantly influenced by the following environmental factors: latitude, elevation, and annual average temperature. Based on the FA levels in the seed oils, clustering analysis divided 14 populations into two clusters. It was found that the average contents of oleic acid, linoleic acid, and total FAs in cluster I (147.16 µg/mg, 200.31 µg/mg, and 671.24 µg/mg, respectively) were significantly lower than those in cluster II (196.65 µg/mg, 220.16 µg/mg, and 741.78 µg/mg, respectively). Cluster I was perfectly consistent with subsect. Foliolatae, while cluster II was in good agreement with subsect. Dissectifoliae. Therefore, the FA composition of wild herbaceous peony seed oil might be used as a chemotaxonomic marker.