Peony Seeds Research Articles

PlZAT10 binds to the ABA catabolism gene PlCYP707A2 promoter to mediate seed dormancy release in Paeonia lactiflora.

PlZAT10-PlCYP707A2 module promotes Paeonia lactiflora seeds germination. The herbaceous peony (Paeonia lactiflora) seeds exhibit double dormancy in the epicotyl and hypocotyl, which significantly inhibits the process of cultivation and breeding of new varieties. Nevertheless, the molecular mechanism underlying seed dormancy release in P. lactiflora remains to be fully identified.In this current study, we analyzed differentially expressed genes based on transcriptome data and selected the abscisic acid catabolic gene PlCYP707A2 for further investigation. The conserved domain of the protein indicated that PlCYP707A2 possessed a cytochrome P450 monooxygenase domain. Subcellular localization indicated that PlCYP707A2 was localized on the cytoplasm and cell membrane. Overexpression of PlCYP707A2 in P. lactiflora seeds decreased ABA contents and promoted seeds germination. The silencing of PlCYP707A2 resulted in seed dormancy and an alteration in the content of ABA. Moreover, yeast one-hybrid, electrophoretic mobility shift and dual-luciferase reporter assay revealed that PlZAT10 bound to the promoter of PlCYP707A2. In conclusion, the results demonstrated the mechanism of the PlZAT10-PlCYP707A2 module in regulating the dormancy release of P. lactiflora seeds, enriching relevant theories on seed dormancy and having significant implications for the herbaceous peony industry developing.

Exploring the Effect of Active Components in Oil Tree Peony Seed Meal on Swine Disease Resistance and its Potential Mechanisms Based on Network Pharmacology and Molecular Docking.

This study aims to explore the feasibility of using network pharmacology and molecular docking technology to predict the effects of active components from oil tree peony seed meal (PSM) on swine diseases. Ten active components of PSM were screened Screening through literature search and network pharmacology standards, including Betulinic acid, Quercetin, Kaempferol, Luteolin, Isorhamnetin, Hydroxygenkwanin, Hederagenin, Benzoyl Paeoniflorin, Albiflorin, Paeoniflorin. Ten types of swine diseases were selected, including African Swine Fever, Aftosa, Swine Vesicular Disease, Transmissible Gastroenteritis, Swine Streptococcal Infection, Blue Aural Disease, Swine Infectious Atrophic Rhinitis, Swine Influenza, Swine Erysipelas, Swine Epidemic Encephalitis. The results showed that the average number of cross genes between the potential target genes of PSM active components and each swine disease target gene accounted for 7.64 % of the total number of swine disease target genes. The GO enrichment analyses showed that putative targets exist in endosomes, lysosomes, cell membranes, nerves, growth factor activity, receptor tyrosine kinase binding, enzyme binding, growth factor binding, transcription coactivator binding, oxidoreductase activity, prostaglandin E receptor activity and insulin receptor substrate binding. The KEGG enrichment analysis results showed that these putative genes were involved in various cancer progression pathways, signaling pathways, and hormone regulatory pathways. A total of 8 core targets were obtained through protein-protein interaction networks analysis, including Protein Kinase CAMP-Activated Catalytic Subunit Alpha (PRKACA), Non-Receptor Tyrosine Kinase (SRC), Mitogen-Activated Protein Kinase 1 (MAPK1), E1A Binding Protein P300 (EP300), Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A), Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Beta (PIK3CB), C-X-C chemokine receptor type 4 (CXCR4) and Estrogen Receptor 2 (ESR2). The HIF-1 signaling pathway was found to be associated with all 10 selected swine diseases. The PD-L1 expression, and PD-1 checkpoint pathway in cancer, and thyroid hormone signaling pathway were not only enriches the core target with a quantity of 7, but also associated with 9 Swine diseases. In addition, the molecular docking results indicate that the core ingredients have strong affinity with hub genes. The research suggests that the active components of PSM may intervene in swine diseases through multiple components, targets, and pathways.

Exogenous melatonin promoted seed hypocotyl germination of Paeonia ostia 'Fengdan' characterized by regulating hormones and starches.

Seed hypocotyl germination signifies the initiation of the life cycle for plants and represents a critical stage that heavily influences subsequent plant growth and development. While previous studies have established the melatonin (MEL; N-acetyl-5-methoxytrytamine) effect to stimulate seed germination of some plants, its specific role in peony germination and underlying physiological mechanism have yet to be determined. This study aims to evaluate the MEL effect for the hypocotyl germination of peony seeds, further ascertain its physiological regulation factors. In this work, seeds of Paeonia ostia 'Fengdan' were soaked into MEL solution at concentrations of 50, 100, 200, and 400 µM for 48 h and then germinated in darkness in incubators. Seeds immersed in distilled water without MEL for the same time were served as the control group. At concentrations of 100 and 200 µM, MEL treatments improved the rooting rate of peony seeds, while 400 µM inhibited the process. During seed germination, the 100 and 200 µM MEL treatments significantly reduced the starch concentration, and α-amylase was the primary amylase involved in the action of melatonin. Additionally, compared to the control group, 100 µM MEL treatment significantly increased the GA3 concentration and radicle thickness of seeds, but decreased ABA concentration. The promotion effect of 200 µM MEL pretreatment on GA1 and GA7 was the most pronounced, while GA4 concentration was most significantly impacted by 50 µM and 100 µM MEL. Correlation analysis established that 100 µM MEL pretreatment most effectively improved the rooting rate characterized by increasing α-amylase activity to facilitate starch decomposition, boosting GA3 levels, inhibiting ABA production to increase the relative ratio of GA3 to ABA. Moreover, MEL increased radicle thickness of peony seeds correlating with promoting starch decomposition and enhancing the synthesis of GA1 and GA7.

Discrete Element Model of Oil Peony Seeds and the Calibration of Its Parameters

Oil peony is an important oil crop that is primarily sown by using artificial methods at present. Its seeder encounters the problems of low efficiency of seeding that significantly limits the highly efficient mechanized production of high-quality peony oil. In this study, Fengdan white oil peony seeds were used as the research object and repose angle as the response value to establish a discrete element model (DEM) and parameter calibration. The range of parameters of oil peony seeds was first obtained through an experiment, and their repose angle was obtained by an inclinometer. A three-dimensional DEM of oil peony seeds was then established. The Plackett–Burman (PB) test was utilized to screen the parameters that had a significant influence on the repose angle, and the steepest ascent (SA) test was applied to determine their optimum range of testing. Following this, based on Box–Behnken (BBD) test results, a second-order regression model between the important parameters and the repose angle was constructed. Finally, the absolute minimum difference between simulated and measured repose angles was utilized as the objective of optimization to obtain the following optimum combination of parameters: The values of the seed–steel collision recovery coefficient (CRC), seed–seed static friction coefficient (SFC), seed–steel SFC, and seed–seed rolling friction coefficient (RFC) were 0.704, 0.324, 0.335, and 0.045, respectively. This optimal combination of parameters was confirmed through simulations, and the error between simulated and measured repose angles was only 0.67%, indicating that the calibrated DEM of oil peony seeds was reliable.

Study on the in Vitro Inhibitory Activity of Peony Seed Blended Oil on α-Amylase and α-Glucosidase

In recent years, China has been suffering from an increasing number of patients with chronic diseases such as diabetes, hypertension, and heart disease, which are gradually showing a "younger" trend. As health problems become more prominent, choosing good cooking oil has become crucial. People are beginning to realize the significance of a balanced diet and healthy eating habits in maintaining good health. Peony seed oil is rich in nutrients, and its content of unsaturated fatty acids can reach over 85%, with the highest content of α-linolenic acid, which effectively lowers blood sugar. Suppose soybean oil and rapeseed oil are combined and added. In that case, the original efficacy of peony seed oil can be complemented and enhanced, its mechanism of action network can be sound, and its nutritional composition can be enriched. We can obtain an optimal ratio for mixing the above several oils by studying their effects and roles. This paper explored the inhibitory effects of peony seed oil, soybean oil, and rapeseed oil on α-amylase activity and α-glucosidase activity, and their optimal ratios were determined by a one-way test and response surface method. The results showed that the optimal ratio was peony seed oil: soybean oil: rapeseed oil = 60:27:13. The results provide specific technology and reference for the development and utilization of peony and provide a particular theoretical basis for the development of hypoglycemic drugs or health food.

Production of Margarine Fat Containing Medium- and Long-Chain Triacylglycerols by Enzymatic Interesterification of Peony Seed Oil, Palm Stearin and Coconut Oil Blends.

This paper reports the preparation of margarine fat using Lipozyme TL IM as a catalyst and peony seed oil (PSO), palm stearin (PS) and coconut oil (CO) as raw materials. The results indicate that there were no significant changes in fatty acid composition before or after interesterification of the oil samples. However, the total amount of medium- and long-chain triglycerides (MLCTs) increased from 2.92% to 11.38% in sample E1 after interesterification, mainly including LaLaO, LaMO, LaPM, LaOO, LaPO and LaPP. Moreover, the slip melting point (SMP) of sample E1 decreased from 45.9 °C (B1) to 33.5 °C. The solid fat content (SFC) of all the samples at 20 °C was greater than 10%, indicating that they could effectively prevent oil exudation. After interesterification, the samples exhibited a β' crystal form and could be used to prepare functional margarine.

Effects of Pulsed Electric Field on Oil Extraction Rate and Tocopherol in Peony Seeds

Peony seed oil, known for its high nutritional value and low production yield, has become a crucial component in high-quality health products. Consequently, enhancing the extraction efficiency of peony seed oil has become an industry objective. Pulse electric field (PEF) technology, as a non-thermal extraction method, has shown promising advancements in improving plant oil yield by enhancing cell permeability. In this study, we designed a static parallel plate PEF treatment unit to process peony seed particles. By manipulating pulse voltage parameters, we investigated the effects of particle size and PEF strength on the oil yield. We also analyzed and evaluated tocopherol in the oil before and after treatment. The results demonstrated that PEF significantly increased the oil yield. Both treated and control groups exhibited gradually increased oil yields with decreasing particle size until reaching saturation at a certain particle size. Increasing voltage frequency did not have a significant impact on the oil yield; however, increasing voltage amplitude resulted in an optimal point for maximum oil yield. Analysis of oil composition indicated that PEF appropriately increased tocopherol content. These findings provide a foundation for further optimization of PEF parameters to assist in extracting peony seed oil and facilitate its industrial application.

Bumblebee pollination ensures the stability of both yield and quality of the woody oil crop Paeonia ostii ‘Fengdan’

Oil tree peony is a unique woody oil crop found exclusively in China. Its seed oil is a highly nutritious edible vegetable oil. However, its seed production varies greatly and is often low. Oil tree peony is a plant that relies on insects for pollination, but inadequate pollination is a common occurrence. In this study, we focused on the Paeonia ostii ‘Fengdan’ species and conducted a five-year study (from 2017 to 2022) in Luoyang, China. Our objective was to assess the extent of pollination deficiency and dependence, as well as quantify the contribution of supplemented bumblebees (Bombus terrestris) to the yield of oil tree peony. We also examined the effect of supplemented bumblebees on the temporal variation in yield through various pollinator survey designs, including supplemented bumblebees (BP), open pollination (OP), pollinator exclusion (EP), self-pollination treatments (SP), and artificial cross-pollination (CP). The results revealed a medium pollination deficit (D = 0.50) at the study sites for three consecutive years from 2020 to 2022, indicating limited pollination for oil tree peony under natural conditions. Importantly, BP significantly compensated for this deficiency (D = 0.22). Over the course of five years, BP increased the yield of oil tree peony by 82.87% on average compared to EP. Furthermore, the yield variation coefficient of EP (CVt=0.20) increased by 100% compared to BP (CVt=0.10). And we also observed significant variability in other yield parameters. Additionally, oil tree peony production was reduced by 44.24% in the absence of flower visitors, and the dependence on BP reached a “high” level. The fatty acid content in the seed oil did not show significant differences across treatments, indicating its stability. Overall, our pollination practices demonstrate that supplementing bee pollination can provide sufficient and stable pollination services, resulting in a higher and more stable yield of oil tree peony seeds.

Identification of Different Varieties of Oil Peony Seeds Combining ICP-MS with Chemometrics and Assessment of Associated Health Risk.

Peony seed is an excellent oil crop, and peony seed oil is rich in unsaturated fatty acids needed by the human body. In this study, inductively coupled plasma mass spectrometry (ICP-MS), fingerprint, and chemometrics, the correlation between the content of inorganic elements in oil peony seeds, their origins, and varieties were investigated. Meanwhile, estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risks (CR) were combined to evaluate the comprehensive health risks of heavy metals in peony seed oil. The results showed that the difference in the content of inorganic elements could identify the varieties of oil peony seeds. Sr, K, Ca, V, Al, Fe, Cu, Ba, As, Ga, Co, and Rb were the characteristic inorganic elements that played a role in identification. In addition, The THQs and HIs (< 1) for non-carcinogenic elements indicated no risk. The CRs indicated that the carcinogenic harm was negligible. The study concluded that three varieties of peony seed oil would not pose any health hazard. It provided an effective comprehensive method for the identification of oil peony seeds and predicted the potential health risks of edible peony seed oil, providing a reference for the development and consumption of peony seed oil food.

Potential Antioxidant Activity of Novel Antioxidant Peptides from Protein Hydrolysate of Peony Seed Dreg in Chemical and H2O2-Induced RAW264.7 Cells

Peony seed dreg protein (PSDP) was hydrolyzed by proteases secreted by Pseudoalteromonas sp. CSN423. This hydrolysate exhibited excellent antioxidant capability after passing through a 3 kDa ultrafiltration membrane. The antioxidant peptides further purified by size-exclusion chromatography scavenged 2, 2-diphenyl-1-picrylhydrazyl (DPPH∙) (73.0 ± 1.46%) and hydroxyl radicals (∙OH) (81.17 ± 3.69%), protected DNA from oxidative injury, and displayed an oxygen radical absorbance capacity (ORAC) of 4.04 ± 1.11 μmol TE/mg. Furthermore, the antioxidant peptide inhibited apoptosis by inhibiting the production of reactive oxygen species (ROS) and the decrease of mitochondrial membrane potential in H2O2-induced RAW264.7 cells. We identified four major peptides such as YFPF, ECCASLAPL, YVSLK, and YFEM by using mass spectrometry. YFPF showed a potent ∙OH scavenging capability of 75.30 ± 1.08%. ECCASLAPL exhibited higher DPPH∙ scavenging capability (87.20 ± 1.03%) than glutathione (GSH) (49.50 ± 1.50%). Moreover, the peptide YVSLK exhibited the highest ORAC of 2.52 ± 1.20 μmol TE/mg of the identified peptides. This work highlights that the peptides from PSDP might have potential uses in cosmetics, functional foods, and drug development.

Comprehensive comparison of different parts of Paeonia ostii, a food-medicine plant, based on untargeted metabolomics, quantitative analysis, and bioactivity analysis.

Paeonia ostii T. Hong & J.X. Zhang (s.s.) (Chinese name, Fengdan) is a widely cultivated food-medicine plant in China, in which root bark, seed kernels, and flowers are utilized for their medicinal and edible values. However, other parts of the plant are not used efficiently, in part due to a poor understanding of their chemical composition and potential biological activity. Untargeted ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-MS) metabolomics was applied to characterize the metabolic profiles of 10 different parts of P. ostii. A total of 160 metabolites were alternatively identified definitely or tentatively, which were significantly different in various plant parts by multivariate statistical analysis. Quantitative analysis showed that underutilized plant parts also contain many active ingredients. Compared with the medicinal part of root bark, the root core part still contains a higher content of paeoniflorin (17.60 ± 0.06 mg/g) and PGG (15.50 ± 2.00 mg/g). Petals, as an edible part, contain high levels of quercitrin, and stamens have higher methyl gallate and PGG. Unexpectedly, the ovary has the highest content of methyl gallate and rather high levels of PGG (38.14 ± 1.27 mg/g), and it also contains surprisingly high concentrations of floralalbiflorin I. Paeoniflorin (38.68 ± 0.76 mg/g) is the most abundant in leaves, and the content is even higher than in the root bark. Branches are also rich in a variety of catechin derivatives and active ingredients such as hydrolyzable tannins. Seed kernels also contain fairly high levels of paeoniflorin and albiflorin. Fruit shells still contain a variety of components, although not at high levels. Seed coats, as by-products removed from peony seeds before oil extraction, have high contents of stilbenes, such as trans-gnetin H and suffruticosol B, showing significant potential for exploitation. Except for the seed kernels, extracts obtained from other parts exhibited good antioxidant activity in DPPH, ABTS, and ferric ion reducing antioxidant power (FRAP) assays (0.09-1.52 mmol TE/g). Five compounds (gallic acid, PGG, trans-resveratrol, kaempferol, and quercitrin) were important ingredients that contributed to their antioxidant activities. Furthermore, P. ostii seed cakes were first reported to possess agonistic activity toward CB1/CB2 receptors. This study provides a scientific basis for the further development and utilization of P. ostii plant resources.

Effect of Peony (Paeonia ostii) Seed Meal Supplement on Enzyme Activities and Flavor Compounds of Chinese Traditional Soybean Paste during Fermentation.

Peony seed meal (PSM) is the by-product obtained from peony seeds after oil extraction. In this study, PSM was incorporated into traditional koji-making, and its impacts on koji enzyme activities and flavor compounds in final products were investigated. In the process of koji fermentation, the optimal addition ratio of PSM to soybean was determined as 7:3. Under this ratio, the maximum enzyme activities of neutral protease, amylase, and glucoamylase were 1177.85, 686.58, and 1564.36 U/g, respectively, and the koji obtained was subjected to maturation. During post-fermentation, changes in the fermentation characteristics of the paste samples were monitored, and it was found that compared to the soybean paste without PSM, the enzyme activities maintained at a relatively good level. The PSM soybean paste contained a total of 80 flavor compounds and 11 key flavor compounds (OAV ≥ 1), including ethyl isovalerate, isovaleric acid, hexanal, phenylacetaldehyde, 3-Methyl-1-butanol 4-heptanone, 2-pentylfuran, methanethiol ester caproate, isoamyl acetate, 3-methyl-4-heptanone, and isovaleraldehyde. These findings could be used to improve the quality of traditional fermented paste, enrich its flavor, and simultaneously promote PSM as a valuable resource for fermented foods.

Effects of Quillaja Saponin on Physicochemical Properties of Oil Bodies Recovered from Peony (Paeonia ostii) Seed Aqueous Extract at Different pH.

Peony seeds, an important oil resource, have been attracting much attention because of α-linolenic acid. Oil bodies (OBs), naturally pre-emulsified oils, have great potential applications in the food industry. This study investigated the effects of extraction pH and Quillaja saponin (QS) on the physicochemical properties of peony oil body (POB) emulsions. POBs were extracted from raw peony milk at pH 4.0, 5.0, 6.0, and 7.0 (named pH 4.0-, 5.0-, 6.0-, and 7.0-POBs). All POBs contained extrinsic proteins and oleosins. The extrinsic proteins of pH 4.0- and pH 5.0-POB were 23 kDa and 38 kDa glycoproteins, the unknown proteins were 48 kDa and 60 kDa, while the 48 kDa and 38 kDa proteins were completely removed under the extraction condition of pH 6.0 and 7.0. The percentage of extrinsic proteins gradually decreased from 78.4% at pH 4.0-POB to 33.88% at pH 7.0-POB, while oleosin contents increased. The particle size and zeta potential of the POB emulsions decreased, whereas the oxidative stability, storage stability, and pI increased with the increasing extraction pH. QS (0.05~0.3%) increased the negative charges of all the POB emulsions, and 0.1% QS significantly improved the dispersion, storage, and the oxidative stability of the POB emulsions. This study provides guidance for selecting the proper conditions for the aqueous extraction of POBs and improving the stability of OB emulsions.

Flavonoids from Peony Seed Meal by Nanofiltration Membrane Separation

Flavonoids are polyphenolic compounds with a wide range of biological activities (antioxidation, antitumor, and immunomodulatory). The membrane separation method of flavonoids has a high recovery and biological activity, overcoming the shortcomings of traditional methods for the separation of bioactive molecules. In this study, ethanol-water ( v / v ) solution was used to extract peony seed meal. The extraction rate of total flavonoids from peony seed meal was 35.28%. Five microfiltration membranes, polypropylene (PP), polyvinylidene fluoride (PVDF), cellulose acetate (CA), polyether sulfone (PES), and polyamide (PA), were selected to pretreat the extracts, and their separation performance was investigated. A new PA-supported silicone film was prepared by sol-gel method using 1,2-bis(TRIMETHOXYSILYL)ETHANE (BTESE) as a carrier. The synthesized BTESE/PA composite membrane was applied to the purification of organic silica PSMF solution by nanofiltration process. The optimal pressure of nanofiltration operation is 0.8 MPa, and the membrane flux can reach 2.06 kg·m-2·h-1. The mass concentration of flavonoids in the retention solution was decreased to 860.56 mg·L-1, and the permeable components of PSMF were effectively separated. The total flavonoid content of the purified lyophilized powder was 146.12 mg·g-1, which was 2.4 times that before purification. The results show that PSMF can be effectively separated by BTESE/PA membrane, and the membrane solution has good antioxidant activity.

Transcriptome Analysis Reveals the Role of Phytohormones in the Distant Hybridization of Peony Embryo Abortion

Peonies are significant ornamental plants that are primarily propagated through distant cross-breeding to create new varieties. However, hybrid failure is a critical issue that impedes the advancement of breeding. Numerous studies have demonstrated that endogenous hormones in the seed embryo constitute a significant factor in embryo failure. Nevertheless, it is still unknown how plant hormones control the development of peony embryos at the molecular level. In this study, we characterized the endogenous hormone levels in peony seeds of hybrid-aborted, hybrid-normal, and self-crossing normal after 26 days of pollination (DAP). Our findings show that the hybrid-aborted embryos had significantly higher amounts of ABA, IAA, and GA. In addition, the ratio of GA+IAA/ABA was lower than that of the hybrid-normal seeds and higher than that of the self-crossing normal seeds. To further investigate the mechanism of hormone control on peony embryo development, we conducted a transcriptome sequencing analysis of the three seed types. Results revealed that differentially expressed genes involved in phytohormone metabolism and signal transduction significantly enriched the aborted embryos. Furthermore, we examined the expression levels of six hormones in different seeds and used the Gene Common Expression Trend analysis to analyze genes highly correlated with phytohormone in the KEGG pathway. We used protein interaction networks to explore the interactions between proteins in the hormone pathway in aborted embryos. Then we identified key genes and transcription factors (TFs) such as Abscisic acid-insensitive 5 (ABI5), Auxin Response Factor 5 (ARF5), Gibberellin Insensitive Dwarf 1 (GID1), Arabidopsis Response Regulator4 (ARR4), Jasmonate-zim-domain protein 1 (JAZ1), Brassinazole-resistant 1 (BZR1), etc., whose functions require further investigation. Our findings establish a foundation for the metabolic regulation of peony hybrid embryo abortion via networks regulating phytohormone signaling. However, further research is needed to determine the exact mechanisms by which hormones regulate peony embryo development and to explore new methods for improving the success rate of hybridization.

Enhancing the Stability and Bioaccessibility of Tree Peony Seed Oil Using Layer-by-Layer Self-Assembling Bilayer Emulsions.

Tree peony seed oil (TPSO) is an important plant source of n-3 polyunsaturated fatty acid (α-linolenic acid, ALA > 40%) that is receiving increasing attention for its excellent antioxidant and other activities. However, it has poor stability and bioavailability. In this study, a bilayer emulsion of TPSO was successfully prepared using a layer-by-layer self-assembly technique. Among the proteins and polysaccharides examined, whey protein isolate (WPI) and sodium alginate (SA) were found to be the most suitable wall materials. The prepared bilayer emulsion contained 5% TPSO, 0.45% whey protein isolate (WPI) and 0.5% sodium alginate (SA) under selected conditions and its zeta potential, droplet size, and polydispersity index were -31 mV, 1291 nm, and 27%, respectively. The loading capacity and encapsulation efficiency for TPSO were up to 84% and 90.2%, respectively. It was noteworthy that the bilayer emulsion showed significantly enhanced oxidative stability (peroxide value, thiobarbituric acid reactive substances content) compared to the monolayer emulsion, which was accompanied by a more ordered spatial structure caused by the electrostatic interaction of the WPI with the SA. This bilayer emulsion also exhibited markedly improved environmental stability (pH, metal ion), rheological properties, and physical stability during storage. Furthermore, the bilayer emulsion was more easily digested and absorbed, and had higher fatty acid release rate and ALA bioaccessibility than TPSO alone and the physical mixtures. These results suggest that bilayer emulsion containing WPI and SA is an effective TPSO encapsulation system and has significant potential for future functional food development.

Integrative lipidomics profile uncovers the mechanisms underlying high-level α-linolenic acid accumulation in Paeonia rockii seeds.

Tree peony (Paeonia rockii) is an excellent woody oilseed crop, known for its high α-linolenic acid (ALA, ~45%) content, which is of great value for human health. However, the mechanisms underlying this high-level ALA accumulation in tree peony seeds are poorly understood. In this study, we evaluated the dynamic changes in the lipidomic profile of P. rockii seeds during development. A total of 760 lipid molecules were identified in P. rockii seeds; triacylglycerol (TAG) lipid molecules showed the highest abundance and diversity, both increasing during seed development. Particularly, ALA was the predominant fatty acid at the TAG sn-3 position. We further characterized two diacylglycerol acyltransferase (DGAT) genes and three phospholipid:diacylglycerol acyltransferase (PDAT) genes involved in the transfer of fatty acids to the TAG sn-3 position. Gene expression and subcellular localization analyses suggested that PrDGATs and PrPDATs may function as endoplasmic reticulum-localized proteins in seed TAG biosynthesis. In vitro functional complementation analysis showed different substrate specificities, with PrPDAT2 having a specific preference for ALA. Multiple biological assays demonstrated that PrDGAT1, PrDGAT2, PrPDAT1-2, and PrPDAT2 promote oil synthesis. Specifically, PrPDAT2 leads to preferential ALA in the oil. Our findings provide novel functional evidence of the roles of PrDGAT1 and PrPDAT2, which are potential targets for increasing the ALA yield in tree peony and other oilseed crops.

Influence of different extraction methods on the chemical composition, antioxidant activity, and overall quality attributes of oils from peony seeds (Paeonia suffruticosa Andr.)

Influence of different extraction methods on the chemical composition, antioxidant activity, and overall quality attributes of oils from peony seeds (Paeonia suffruticosa Andr.)

Effect of Adsorption Deacidification on the Quality of Peony Seed Oil.

To overcome the issues in the traditional deacidification processes of peony seed oil (PSO), such as losses of neutral oil and trace nutrients, waste discharge, and high energy consumption, adsorption deacidification was developed. The acid removal capacity of adsorbent-alkali microcrystalline cellulose was evaluated using the isothermal adsorption equilibrium and the pseudo-first-order rate equation. The optimized adsorption deacidification conditions included adsorbent-alkali microcrystalline cellulose at 3%, a heating temperature of 50 °C, and a holding time of 60 min. The physicochemical, bioactive properties, antioxidant capacities, and oxidative stabilities of PSO processed by alkali refining and oil-hexane miscella deacidification were compared under the same operating conditions. Fatty acid content was not significantly different across all three methods. The deacidification rates were 88.29%, 98.11%, and 97.76%, respectively, for adsorption deacidification, alkali refining, and oil-hexane miscella deacidification. Among the three deacidification samples, adsorption deacidification showed the highest retention of tocopherols (92.66%), phytosterols (91.96%), and polyphenols (70.64%). Additionally, the obtained extract preserved about 67.32% of the total antioxidant activity. The oil stability index was increased 1.35 times by adsorption deacidification. Overall, adsorption deacidification can be considered a promising extraction technology in terms of quality as compared to alkali refining and oil-hexane miscella deacidification.

Genomic basis of the giga-chromosomes and giga-genome of tree peony Paeonia ostii

Tree peony (Paeonia ostii) is an economically important ornamental plant native to China. It is also notable for its seed oil, which is abundant in unsaturated fatty acids such as α-linolenic acid (ALA). Here, we report chromosome-level genome assembly (12.28 Gb) of P. ostii. In contrast to monocots with giant genomes, tree peony does not appear to have undergone lineage-specific whole-genome duplication. Instead, explosive LTR expansion in the intergenic regions within a short period (~ two million years) may have contributed to the formation of its giga-genome. In addition, expansion of five types of histone encoding genes may have helped maintain the giga-chromosomes. Further, we conduct genome-wide association studies (GWAS) on 448 accessions and show expansion and high expression of several genes in the key nodes of fatty acid biosynthetic pathway, including SAD, FAD2 and FAD3, may function in high level of ALAs synthesis in tree peony seeds. Moreover, by comparing with cultivated tree peony (P. suffruticosa), we show that ectopic expression of class A gene AP1 and reduced expression of class C gene AG may contribute to the formation of petaloid stamens. Genomic resources reported in this study will be valuable for studying chromosome/genome evolution and tree peony breeding.