Search Results (95)

The edible tree peony (Paeonia suffruticosa Andrews) flowers are rich in bioactive components with potential health benefits, but the skin-health-promoting effects of their protein hydrolysates remain understudied. The present research sought to evaluate the antioxidant, anti-wrinkle, moisturizing, and whitening properties of tree peony flower protein hydrolysate (TPFP). TPFP was prepared via enzymatic hydrolysis and ultrafiltration, and its peptide sequences were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing 54 unique small-molecule peptides with an average amino acid length of 8.2 residues and a molecular weight of 914.51 Da. In vitro safety evaluation using CCK-8 assay showed TPFP (20–100 μM) did not induce substantial cytotoxic effects in either HaCaT keratinocytes or B16F10 melanoma cell lines. Functional assays demonstrated that TPFP dose-dependently inhibited UVB-induced reactive oxygen species (ROS) overproduction and restored superoxide dismutase (SOD) and catalase (CAT) activities in HaCaT cells, exerting antioxidant effects. Additionally, TPFP protected pro-collagen I from UVB-induced loss, suppressed the expression of matrix metalloproteinase 1 (MMP-1), and restored hyaluronic acid (HA) content, showing anti-wrinkle and moisturizing potentials. In α-MSH-stimulated B16F10 cells, TPFP suppressed melanin synthesis by downregulating the protein expression of tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and TRP-2, achieving a whitening effect. These findings indicate that TPFP possesses comprehensive skin-health-promoting activities with good biocompatibility, highlighting its potential as a natural functional ingredient in cosmetics and functional foods. Full article

Tree peony (Paeonia sect. Moutan) is one of the most important traditional ornamental woody flowers in China. However, its cultivation is often challenged by intense light and high temperatures during summer, leading to severe photo-oxidative damage and leaf senescence. In this study, we investigated the protective effects of polyolefin (PO) film on potted tree peony leaves under summer intense light and high temperature stress. Using tree peony ‘Luoyanghong’ as experimental material, we systematically compared the effects of two controls under natural light (CK1 and CK2, housed in separate greenhouses), single-layer PO film (PO1), and double-layer PO film (PO2) treatments. Microenvironment monitoring showed that single-layer and double-layer PO films reduced light intensity by 21% and 49%, respectively, while having limited effects on temperature. Morphological and physiological analyses indicated that PO film treatments effectively alleviated leaf yellowing and withering, maintained normal physiological morphology, and increased chlorophyll (Chl) and carotenoid (Car) content. The net photosynthetic rates of PO1 and PO2 plants were 18–36% higher than those of the control groups (CK1 and CK2). Evans blue and NBT staining revealed that PO film reduced cellular damage and reactive oxygen species (ROS) accumulation, while decreasing malondialdehyde (MDA) levels and increasing catalase (CAT) activity. Furthermore, qRT-PCR results showed that stress-responsive genes (Hsp70, Hsp90, and ATG5) and photosynthetic genes (RbcS and RbcL) were upregulated under PO film treatment. Principal component analysis (PCA) indicated that high light intensity, rather than temperature, was the primary factor causing leaf damage in potted tree peonies. The results show that PO film is an effective and low-cost agronomic measure, which can alleviate the intense light stress under high temperature conditions, relieve photo-oxidative damage, maintain photosynthetic performance, and increase the survival rate of potted tree peonies in summer. Full article

Carbohydrate accumulation during seed development directly influences the oil yield and quality of oilseed plants. To clarify the metabolic and molecular mechanisms underlying this process, we examined seed morphology, metabolome, and transcriptome profiles of Paeonia ostii, a representative oil tree peony, using molecular biology, bioinformatics, and GC-MS techniques. Seeds expanded rapidly and reached their maximum size at 60 days after pollination, coinciding with increased starch staining intensity. Carbohydrate metabolic patterns indicated the conversion of monosaccharides such as glucose, fructose, and inositol into disaccharides like sucrose and into polysaccharides, including starch, raffinose, cellulose, and hemicellulose. Differentially accumulated carbohydrates and associated genes were enriched in the starch and sucrose metabolism and ABC transporter pathways. We constructed a potential regulatory network comprising genes encoding sugar transporters (SWEET, SUS), glycosyl hydrolases, and transcription factors (NF-Y, MYB, LBD, Dof, and B3), which likely play essential roles in carbohydrate deposition and seed development. Therefore, this study clarifies the metabolic and molecular processes governing carbohydrate accumulation in developing seeds and provides a basis for breeding high-yield, high-quality oil tree peony varieties. Full article

Background: Tree peony (Paeonia section Moutan DC.) seeds, renowned for their rich content of unsaturated fatty acids, hold significant medicinal and nutritional value. Despite their potential, their yield is relatively low, which constrains economic gains and health benefits. Brassinosteroids (BRs), emerging as potent plant growth regulators, have demonstrated efficacy in boosting plant productivity. Methods: This study employed Paeonia ostii ‘Fengdan’ and administered either water (control group, CKs) or 0.05 mg/L BRs through foliar application during the seed enrichment and conversion phase to assess the effects of BR treatment on seed yield. Results: The BR treatment notably enhanced the protein, starch, and sugar content and yield of P. ostii ‘Fengdan’ seeds, surpassing those of the CKs. Transcriptome profiling identified a plethora of differentially expressed genes in P. ostii ‘Fengdan’ in response to BR treatment, which are implicated in biological processes associated with nutrient reservoir activity. KEGG analysis highlighted the pivotal role of starch and sucrose metabolism in the BR treatment response. WGCNA revealed key gene expression modules that correlate with physiological traits in P. ostii ‘Fengdan’. Furthermore, the quantitative real-time PCR (qRT-PCR) validation of key genes in this pathway revealed that BR treatment enhances yield through a dual mechanism: accelerating the seed-filling process and optimizing developmental timing for earlier maturation. Conclusions: Collectively, these findings offer inaugural comprehensive genomic resources delineating the transcriptional regulatory mechanisms of BRs in P. ostii ‘Fengdan’ seeds. Full article

Continuous cropping can often deteriorate soil quality and reduce crop yield. Soil properties and microbial communities usually play a vital role in maintaining rhizosphere micro-ecosystem sustainability, which is yet to be addressed in continuous peony monoculture systems. Herein, variations in soil physiochemical properties were extensively investigated following 1, 4, and 10 years of continuous tree peony cropping, as well as microbial community diversity, composition, and predicted functions. The soil pH and contents of available Mg, Mn, Zn, and B significantly declined after 10 years of continuous monoculture, while the contents of soil organic carbon, nitrate, and available P, K, Fe, and Cu notably increased by more than 100%, implying an imbalance of soil nutrients resulting from long-term continuous cropping. High-throughput sequencing results indicated that the microbial community structure and composition were remarkably altered after either 4 or 10 years of continuous cropping, interfering with diverse microbial metabolic pathways and phenotype functions. In addition, the relative abundances of some beneficial bacteria dramatically increased, especially for Acidobacteriota and Bacillus members. Microbial selections or adaptations in response to soil nutrient changes were expected to remediate negative impacts of continuous cropping on soil quality. Findings in this study provide insights into the establishment of proper management strategies for sustaining soil quality to resist potential obstacles after long-term continuous peony cropping. Full article

Tree peony is an important horticultural plant with both ornamental and oil value. The tree peony genome and databases were used to search for calmodulin family genes to explore their function in the pollination of tree peony. The CaM gene family was identified, and then the basic protein characteristics of the family members, such as gene structure, isoelectric point, molecular weight, subcellular localization, and conserved protein domain, were analyzed. The expression levels of these genes in the pistil tissue of Paeonia ostii ‘Fengdan’ at different developmental stages after pollination were also analyzed. Further, qRT-PCR was used to detect the expression levels of six PsCaMs during the development process of the pistil under bee pollination conditions. The results showed that there were six CaM family members located on three chromosomes and one non-chromosome. There were a large number of hormone response and stress response elements on the gene promoter of this family. During the development of pistil tissue after pollination, CaM family gene expression showed a trend of first increasing and then decreasing, which may be related to its function during pollination. The purpose of this study is to identify the gene characteristics and expression patterns of the CaM family during pollination, and to lay a foundation for the functional study of the CaM family in tree peony pollination. Full article

Selenium (Se) is an essential micronutrient for human health, yet its deficiency remains prevalent worldwide. Biofortification through foliar Se application is an effective strategy to enhance Se levels in crops. Paeonia ostii ‘Fengdan’ is a multifunctional woody plant with potential for Se enrichment, though its Se uptake and transformation mechanisms remain unclear. This study systematically investigated the effects of foliar-applied Na₂SeO₃ (0–200 mg L⁻¹) on Se uptake, accumulation, speciation, and nutritional quality in tree peony. Results showed that Se uptake increased with higher Na₂SeO₃ concentrations, displaying a clear dose-dependent pattern across all organs. Se accumulation significantly enhanced, with a pronounced shift in distribution towards above-ground organs under experimental conditions. Notably, tree peony exhibited strong biotransformation capacity, converting over 73% of Se in leaves and over 81% in seeds into organic forms, primarily SeCys₂ and SeMet, with minor MeSeCys. Comprehensive evaluation indicated that 100 mg L⁻¹ Na₂SeO₃ yielded optimal results, significantly enhancing leaf and seed biomass, increasing seed nutrient contents (soluble proteins, sugars, phenolics), and improving the unsaturated fatty acid profile of seed oil. These findings highlight tree peony’s potential as an efficient bioreactor for organic Se and provide a theoretical foundation for developing Se-enriched products from tree peony. Full article

Tree peony (Paeonia ostii) is widely cultivated in China as a traditional medicine and a new high-quality woody oil crop. Enhancing seed yield has become a primary breeding objective in the industrial development of oil tree peonies. Pollination and successful fertilization are essential for optimal seed yield. However, the molecular mechanisms underlying pollination and fertilization in P. ostii remain unclear. In this study, comparative transcriptomic and genetic analyses were conducted to investigate the pistils under different pollination periods of P. ostii ‘Fengdanbai’. Compared with pre-pollination, differentially expressed genes (DEGs) were screened from pistils 48 h after pollination, when most of the pollen tubes had reached the bottom of the style. Functional annotation indicated that these DEGs were involved in hormone signaling and carbohydrate metabolism pathways. Transcription factors and receptor-like kinases play a key role in pollen development, pollen tube growth, and carpel development. Key DEGs (PoUNE10 and PoLIM1) influenced pollination and fertilization and were characterized. Phylogenetic, promoter, and co-expression analyses suggest that they may affect plant pollination, fertilization, and seed yield through pathways such as hormone signaling and photosynthesis in P. ostii ‘Fengdanbai’. Our findings illustrate the molecular changes after pollination and fertilization in P. ostii ‘Fengdanbai’ and provide the molecular characterization of two key genes. These results provide insights into the molecular mechanisms underlying pollination and fertilization in tree peony and suggest potential candidate genes for molecular breeding aimed at improving seed yield in the species. Full article

Potted cultivation serves as a vital strategy for industrialized production of standardized tree peonies, engineering seedlings capable of year-round and off-site transplantation. However, the limited root zone in potted conditions restricts root development, resulting in suboptimal seedling quality and hindering commercial-scale production. This study aimed to investigate the relationship between the accumulation characteristics of non-structural carbohydrates (NSCs) and growth performance in potted tree peonies, while also optimizing the transplantation technologies for potted cultivation. Using two-year-old grafted seedlings of ‘Luoyanghong’ as experimental material, the effects of root pruning, rooting agent, and Metarhizium anisopliae application on morphological development and NSCs accumulation in potted tree peony seedlings were investigated. The results showed that old roots serve as the primary storage organs for NSCs in the potted tree peony. Slight root pruning (25%) was beneficial for fibrous root growth, whereas excessive root pruning (50%) resulted in reduced biomass and NSCs accumulation. The application of a high concentration of rooting agents effectively promoted root growth and mitigated the adverse effects of root pruning. Furthermore, Metarhizium anisopliae significantly increased the stem number in potted tree peonies. The optimal protocol identified through range analysis involved 25% root pruning, followed by irrigation with a solution containing 750 mg·L⁻¹ rooting agent and 20 million spores·mL⁻¹ of Metarhizium anisopliae. The rational distribution of NSCs and coordinated growth across different organs enhanced NSCs accumulation in potted tree peonies. These results demonstrate that combining root pruning with the application of rooting agent and Metarhizium anisopliae can effectively increase NSCs accumulation, optimize plant morphology, and ultimately improve the quality of potted tree peony seedlings. Full article

Tree peony is well-known for its ornamental value, medicine function, oil, and edible use. However, the difficulty in propagating tree peony impedes its cultivation and industrial advancement. Softwood cutting is an effective method to promote the propagation of tree peony. This research investigated the effects of several factors (cultivar, cutting phenological stage, auxin type, polyamine, and substrate) on the rooting of softwood cutting in tree peony. The results showed that rooting ability varied with cultivars and cutting phenological stages, with the highest rooting rates being for ‘High noon’ and ‘Jinghua Qingxue’ during the vigorous growth stage, reaching 50% and 53.33%, respectively. IBA 2000 mg·L⁻¹ was optimal for rooting in ‘High noon’ cuttings, with the maximum root number (5.67) and root length (6.3 cm). Putrescine of 1.0 mM could significantly improve the rooting rate and rooting quality of ‘Jinghua Qingxue’ cuttings, which had the highest rooting rate of 54.17% in the cocopeat/perlite substrate (v:v 1:1). Anatomical observation showed that most adventitious roots were generated from callus meristem nodules differentiated from cortical parenchyma cells while a few came from stem bark, as well as integrated root induction. This study is an innovation in and supplement to tree peony propagation research, and a propagation protocol was primarily established for softwood cuttings in tree peony. Full article

Peonies (Paeonia spp.) are renowned for their beautiful ornamental flowers and significant cultural, medicinal, and economic values. Based on growth habit, peonies are categorized into herbaceous and tree peonies. Viral infections in peonies, historically referred to as “peony ringspot” or “peony mosaic” diseases, have been reported worldwide over decades. Infections symptoms typically include leaf discoloration and diminished flowering, substantially reducing both ornamental and commercial quality. In severe cases, viral diseases can cause stunted plant growth and impaired flowering, directly affecting peony cultivation and the floriculture profitability. This review systematically summarizes the current research on key viral diseases in peonies, addressing disease classification, symptomatology, causative viruses, pathogenesis, molecular virus–host interactions, and contemporary approaches for prevention and management. The insights provided in this review offer a theoretical foundation and practical guidelines to facilitate effective control of peony viral diseases, potentially promoting sustainable development within the peony industry. Full article

The tree peony holds significant historical, cultural, and practical value. P. ostii is extensively cultivated in China, where it represents the primary oil-producing variety of tree peonies. However, the current nutrient supplementation system for P. ostii lacks an empirical basis, resulting in frequent wastage of nutrients during daily production. In this study, varying ratios and quantities of nitrogen, phosphorus, and potassium were administered to P. ostii at distinct phases of its annual growth cycle, specifically during the bud sprouting, post-flowering, and dormancy periods. The results showed that during the bud sprouting period, the plants treated with a high nitrogen and potassium ratio (a high N&K ratio, N–P–K = 35%–20%–35%) had better flowering traits than those treated with a high phosphorus ratio (a high P ratio, N–P–K = 20%–35%–20%). Under the standard application amount, plants treated with a high N&K ratio outperformed those treated with a high P ratio in terms of flowering duration, net photosynthetic rate, and flowering biomass, with increases of 20.9%, 10.7%, and 32.9%, respectively. During the post-flowering period, all plants died when treated with 1.5 × standard amounts of the above ratios. At this period, the all-high ratio with N–P–K = 45%–45%–45% resulted in a 70.4% increase in fruit set, a 43.8% increase in seed number, and a 153.8% increase in biomass compared with the high N&K ratio. During the dormancy period, nutrient supplementation with the standard amount of P led to higher increases in ground diameter and biomass. Therefore, in subsequent tree peony production, particular attention should be paid to nutrient supplementation during the post-flowering period to prevent excessive fertilizer application and safeguard the plants’ normal growth and development. Full article

Peonies are globally renowned ornamental plants, and distant hybridization is a key method for breeding new varieties, though it often faces cross-incompatibility challenges. The metabolic mechanisms underlying the crossing barrier between tree peony (Paeonia sect. Moutan) and herbaceous peony (P. lactiflora) remain unclear. To identify key metabolites involved in cross-incompatibility, we performed a cross between P. ostii ‘Fengdanbai’ (female parent) and P. lactiflora ‘Red Sara’ (male parent) and analyzed metabolites in the stigma 12 h after pollination using UPLC-MS. We identified 1242 differential metabolites, with 433 up-regulated and 809 down-regulated, including sugars, nucleotides, amino acids, lipids, organic acids, benzenoids, flavonoids, and alkaloids. Most differential metabolites were down-regulated in hybrid stigmas, potentially affecting pollen germination and pollen tube growth. Cross-pollinated stigma exhibited lower levels of high-energy nutrients (such as amino acids, nucleotides, and tricarboxylic acid cycle metabolites) compared to self-pollinated stigma, which suggests that energy deficiency is a contributing factor to the crossing barrier. Additionally, cross-pollination significantly impacted KEGG pathways such as nucleotide metabolism, purine metabolism, and vitamin B6 metabolism, with most metabolites in these pathways being down-regulated. These findings provide new insights into the metabolic basis of cross-incompatibility between tree and herbaceous peonies, offering a foundation for overcoming hybridization barriers in peony breeding. Full article

Paeonia ludlowii is a threatened and valuable germplasm in the cultivated tree peony gene pool, with distinctive traits such as tall stature, pure yellow flowers, and scarlet foliage in autumn. However, the crossability barrier limits gene transfer from P. ludlowii to cultivated tree peony. Therefore, our study investigated the reasons for the lack of crossability between P. ludlowii and Paeonia ostii ‘Fengdan’. Distant cross pollination (DH) resulted in the formation of many calloses at the ends of the pollen tubes, which grew non-polar, twisted, entangled, and often stopped in the style. Pollen tubes elongated the fastest in self-pollination (CK), and pollen tubes elongated faster and fewer pollen tube abnormalities were observed in stigmas treated with KCl solution before pollination (KH) than in DH. During pollen–pistil interactions, the absence of stigma exudates, high levels of H₂O₂, O₂⁻, MDA, ^•OH, ABA, and MeJA, and lower levels of BR and GA₃ may negatively affect pollen germination and pollen tube elongation in the pistil of P. ostii ‘Fengdan’. Pollen tubes in CK and KH penetrated the ovule into the embryo sac at 24 h after pollination, whereas only a few pollen tubes in DH penetrated the ovule at 36 h after pollination. Pre-embryo abnormalities and the inhibition of free nuclear endosperm division resulted in embryo abortion in most of the fruits of DH and many fruits of KH, which occurred between 10 and 20 days after pollination, whereas embryos in CK developed well. Early embryo abortion and endosperm abortion in most of the fruits of DH and KH led to seed abortion. Seed abortion in KH and DH was mainly due to an insufficient supply of auxins and gibberellins and lower content of soluble protein and soluble sugars. The cross failure between P. ludlowii and P. ostii ‘Fengdan’ is mostly caused by a pre-fertilization barrier. KH treatment can effectively promote pollen tube growth and facilitate normal development of hybrid embryos. These findings provide new insights into overcoming the interspecific hybridization barrier between cultivated tree peony varieties and wild species. Full article

The spraying time of nitrogen fertilizer is a key factor to consider when fertilizing with an intelligent micro-sprinkler irrigation system. This study aims to investigate the impact of nitrogen fertilizer spraying time on the seed oil quality of tree peony, with the expectation of providing theoretical support for the application of intelligent micro-sprinkler irrigation systems in the production of tree peony. In 2022 and 2023, foliar nitrogen application was conducted on Paeonia ostii ‘Fengdan’ utilizing an intelligent micro-spray irrigation system, with four distinct nitrogen fertilizer spraying times (3:00–4:00, 7:00–8:00, 14:00–15:00, and 19:00–20:00). Based on this, the study assessed nitrogen metabolism indicators in leaves and seeds at various growth stages and the fatty acid composition of seed oil in Paeonia ostii ‘Fengdan’. The results revealed that foliar nitrogen application between 14:00 and 15:00 significantly enhanced the levels of free amino acids (FAA), nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) activity in both leaves and seeds. Furthermore, the ratio of α-linolenic acid in the seed oil was significantly increased. Correlation analysis demonstrated a positive or highly significant positive correlation between the levels of nitrogen metabolism indicators and the ratio of unsaturated fatty acids. In conclusion, foliar nitrogen application between 14:00 and 15:00 significantly enhances the FAA content and the activity of nitrogen metabolism enzymes within the leaves and seeds and promotes the synthesis of unsaturated fatty acids in seed oil. This study contributes to the efficient and high-quality cultivation of tree peony. Full article