Search Results (15)

Background: The peony (Paeonia suffruticosa Andr.), a globally valued woody ornamental species, suffers severe heat-induced floral damage that compromises its horticultural value. While the HSP20 proteins are critical for plant thermotolerance, their genomic organization and regulatory dynamics remain uncharacterized in the peony. This study aims to systematically identify the PsHSP20 genes, resolve their molecular features, and elucidate their heat-responsive expression patterns to enable targeted thermotolerance breeding. Methods: The genome-wide identification employed HMMER and BLASTP searches against the peony genome. The physicochemical properties and protein structures of the gene family were analyzed using online websites, such as Expasy, Plant-mPLoc, and SOPMA. The cis-regulatory elements were predicted using PlantCARE. Expression profiles under different times of 40 °C heat stress were validated by qRT-PCR (p < 0.05). Results: We identified 58 PsHSP20 genes, classified into 11 subfamilies. All members retain the conserved α-crystallin domain, and exhibit predominant nuclear/cytoplasmic localization. Chromosomal mapping revealed uneven distribution without lineage-specific duplications. The promoters were enriched in stress-responsive elements (e.g., HSE, ABRE) and in 24 TF families. The protein networks linked 13 PsHSP20s to co-expressed partners in heat response (GO:0009408) and ER protein processing (KEGG:04141). Transcriptomics demonstrated rapid upregulation of 48 PsHSP20s within 2 h of heat exposure, with PsHSP20-12, -34, and -51 showing the highest induction (>15-fold) at 6 h/24 h. Conclusions: This first genome-wide study resolves the architecture and heat-responsive dynamics of the PsHSP20 family. The discovery of early-induced genes (PsHSP20-12/-34/-51) provides candidates for thermotolerance enhancement. These findings establish a foundation for molecular breeding in the peony. Full article

Gibberellin (GA₃) plays a crucial role in regulating the flowering time of tree peony (Paeonia suffruticosa Andr.). However, its function on flower opening after dormancy release remains unclear, and its molecular mechanism need further study. We investigated the effects of exogenous GA₃ treatments at 800 mg/L, 900 mg/L, and 1000 mg/L on the flowering process of five-year-old peony plants (‘Luhehong’) under greenhouse conditions. Our results showed that exogenous GA₃ significantly accelerated the flower opening process. Specifically, flower buds treated with 800 mg/L and 900 mg/L GA₃ bloomed after 42 and 45 days, respectively. In contrast, all flower buds treated with 1000 mg/L GA₃ aborted, while only one flower bud in the control group bloomed after 56 days. Furthermore, analysis of endogenous hormone levels revealed that GA₃ treatment rapidly increased endogenous GA₃ levels, decreased ABA levels, and gradually increased IAA levels. Transcriptomic analysis of flower buds released from dormancy following GA₃ treatment identified multiple key genes involved in the flower opening process of peony. Notably, members of the C2H2, C3H, ERF, bHLH, MYB, bZIP, NAC, and WRKY families showed significant differential expression. Moreover, several key genes involved in GA₃, ABA, and IAA hormone signaling pathways were also differentially expressed. Our findings suggested that an appropriate concentration of exogenous GA₃ treatment could accelerate the flower opening process in tree peony through multiple pathways, which would provide valuable insights into the molecular mechanisms underlying the gibberellin-mediated flower opening process in tree peony. Full article

Paeonia suffruticosa Andr. (tree peony) and Paeonia lactiflora Pall. (herbaceous peony) are traditional Chinese flowers with great ornamental value. To maintain the aesthetic value and show the characteristics of these species, preserved flowers named ‘germplasm display balls’ were developed. Firstly, dried flowers were obtained by vacuum freeze-drying. Secondly, to embed dried flowers and develop germplasm display balls, highly transparent crystal glue (in wrapped display balls type 1 and drop-type display balls type 2) and highly transparent silicone gel (in wrapped display balls, type 3) were used. Finally, the first pass yield (FPY), labor productivity (LP), average cost (AC), and popularity of three kinds of germplasm display balls were compared. The results showed that with the support of a paper cup, the deformation rate of flowers significantly decreased by 91.11%. The FPY of dried flowers was as high as 98.89% at 18 °C. The optimal process for type 1 and type 2 was a glue dosage of 20 g, stirring time of 3 min, and room temperature of 25 °C. Although there was a higher AC in type 3 display ball process, moderate LP and higher FPY and popularity than in other two types, accompanied by high durability, render it the best choice. Full article

Tree peony (Paeonia suffruticosa Andr.), which is a traditional flower cultivated in China, is rapidly becoming an important species in the cut flower industry. Thus, extending the vase life of tree peony cut flowers is a major goal in the cut flower industry. Melatonin, which is a new type of antioxidant, plays an important regulatory role in the preservation of cut flowers. Therefore, this study employed the cut flower of tree peony “Diguan” as the test material to investigate the preservative effects of the antioxidant melatonin on the cut flower of tree peony “Diguan”. We examined tree peony cut flowers in terms of their morphology, lifespan, relative fresh weight, relative diameter, and water balance value after treatments with different melatonin concentrations (0.2, 0.3, 0.4, and 0.5 mg·L⁻¹) to select the optimal treatment concentration. Considered together, these analyses clarified the effects of melatonin on the preservation of “Diguan” tree peony cut flowers. Specifically, the exogenous application of melatonin positively affected the preservation of tree peony cut flowers by improving the water balance value and increasing the soluble protein content and antioxidant enzyme activities, thereby prolonging the ornamental period of tree peony cut flowers. The fresh weight of flower branches is significantly positively correlated with soluble protein, and cut flower lifespan increases with the values of soluble protein and the fresh weight of flower branches, with a large correlation coefficient. It can be used as an important indicator to measure cut flower lifespan in subsequent research. The 0.4 mg L⁻¹ melatonin treatment was optimal for preserving tree peony cut flowers because of its positive effects on the duration of the ornamental period and ornamental quality. Full article

Tree peony (Paeonia suffruticosa Andr.) is a woody plant with high ornamental, medicinal, and oil values. However, its low rooting rate and poor rooting quality are bottleneck issues in the micropropagation of P. ostii. The WUSCHEL-related homeobox (WOX) family plays a crucial role in root development. In this study, based on the screening of the genome and root transcriptome database, we identified ten WOX members in P. ostii. Phylogenetic analysis revealed that the ten PoWOX proteins clustered into three major clades, the WUS, intermediate, and ancient clade, respectively. The conserved motifs and tertiary structures of PoWOX proteins located in the same clade exhibited higher similarity. The analysis of cis-regulatory elements in the promoter indicated that PoWOX genes are involved in plant growth and development, phytohormones, and stress responses. The expression analysis revealed that PoWOX genes are expressed in distinct tissues. PoWOX4, PoWOX5, PoWOX11, and PoWOX13b are preferentially expressed in roots at the early stage of root primordium formation, suggesting their role in the initiation and development of roots. These results will provide a comprehensive reference for the evolution and potential function of the WOX family and offer guidance for further study on the root development of tree peony. Full article

Tree peony (Paeonia suffruticosa Andr.) is a traditional Chinese flower with significant ornamental and medicinal value. Its growth and development process is regulated by some internal and external factors, and the related regulatory mechanism is largely unknown. Myelocytomatosis transcription factors (MYCs) play significant roles in various processes such as plant growth and development, the phytohormone response, and the stress response. As the identification and understanding of the MYC family in tree peony remains limited, this study aimed to address this gap by identifying a total of 15 PsMYCs in tree peony and categorizing them into six subgroups based on bioinformatics methods. Furthermore, the gene structure, conservative domains, cis-elements, and expression patterns of the PsMYCs were thoroughly analyzed to provide a comprehensive overview of their characteristics. An analysis in terms of gene structure and conserved motif composition suggested that each subtribe had similarities in function. An analysis of the promoter sequence revealed the presence of numerous cis-elements associated with plant growth and development, the hormone response, and the stress response. qRT-PCR results and the protein interaction network further demonstrated the potential functions of PsMYCs in the growth and development process. While in comparison to the control, only PsMYC2 exhibited a statistically significant variation in expression levels in response to exogenous hormone treatments and abiotic stress. A promoter activity analysis of PsMYC2 revealed its sensitivity to Flu and high temperatures, but exhibited no discernible difference under exogenous GA treatment. These findings help establish a basis for comprehending the molecular mechanism by which PsMYCs regulate the growth and development of tree peony. Full article

Peony seed oil, a type of tree nut oil, has attracted the attention of nutritionists for its rich nutritional content. The aim of this study was to extract oil from the peony seed utilizing green and efficient methods. Specifically, aqueous enzymatic extraction was optimized using the Plackett–Burman design combined with the mixture design to extract the optimal enzyme ratio of peony seed oil. When the dosage of enzymes was 10 mg protein/g peony seed, the optimal ratios of the dosages of papain, cellulase, and pectinase were 16.15%, 31.33%, and 52.53%, respectively. Subsequently, central composite design was adopted to optimize supercritical CO₂ extraction to identify the process parameters of extracting residual oil from the residue of the aqueous enzymatic extraction. Almost 6.30% of peony seed oil could be obtained from the residue using continuous extraction for 1.58 h at 49.41 °C and 59.75 Mpa. After mixing the peony seed oil extracted by the two processes, its physicochemical indices were measured. Compared with commercial peony seed oil extracted based on the organic solvent leaching method, the elative density and iodine value were higher based on our approach, whereas the other indices showed no significant differences. Thus, the two-step strategy combining the aqueous enzymatic method and supercritical CO₂ extraction can be effectively applied to peony seed oil production. Full article

Paeonia suffruticosa Andr., a member of Paeoniaceae, is native to China. In its 1600 years’ cultivation, more than 2000 cultivars for different purposes (ornamental, medicinal and oil use) have been inbred. However, there are still some controversies regarding the provenance of tree peony cultivars and the phylogenetic relationships between and within different cultivar groups. In this study, plastid genome sequencing was performed on 10 representative tree peony cultivars corresponding to 10 different flower types. Structure and comparative analyses of the plastid genomes showed that the total lengths of the chloroplast genome of the 10 cultivars ranged from 152,153 to 152,385 bp and encoded 84–88 protein-coding genes, 8 rRNAs and 31–40 tRNAs. The number of simple sequence repeats and interspersed repeat sequences of the 10 cultivars ranged from 65–68 and 40–42, respectively. Plastid phylogenetic relationships of Paeonia species/cultivars were reconstructed incorporating data from our newly sequenced plastid genomes and 15 published species, and results showed that subsect. Vaginatae was the closest relative to the central plains cultivar group with robust support, and that it may be involved in the formation of the group. Paeonia ostii was recovered as a successive sister group to this lineage. Additionally, eleven morphological characteristics of flowers were mapped to the phylogenetic skeleton to reconstruct the evolutionary trajectory of flower architecture in Paeoniaceae. Full article

Suffruticosol B (Suf-B) is a stilbene found in Paeonia suffruticosa ANDR., which has been traditionally used in medicine. Stilbenes and their derivatives possess various pharmacological effects, such as anticancer, anti-inflammatory, and anti-osteoporotic activities. This study aimed to explore the bone-forming activities and mechanisms of Suf-B in pre-osteoblasts. Herein, >99.9% pure Suf-B was isolated from P. suffruticosa methanolic extracts. High concentrations of Suf-B were cytotoxic, whereas low concentrations did not affect cytotoxicity in pre-osteoblasts. Under zero levels of cytotoxicity, Suf-B exhibited bone-forming abilities by enhancing alkaline phosphatase enzyme activities, bone matrix calcification, and expression levels with non-collagenous proteins. Suf-B induces intracellular signal transduction, leading to nuclear RUNX2 expression. Suf-B-stimulated differentiation showed increases in autophagy proteins and autophagosomes, as well as enhancement of osteoblast adhesion and transmigration on the ECM. These results indicate that Suf-B has osteogenic qualities related to differentiation, autophagy, adhesion, and migration. This also suggests that Suf-B could have a therapeutic effect as a phytomedicine in skeletal disorders. Full article

Peony (Paeonia suffruticosa Andr.) is a traditional ornamental flower in China. Peony potted culture has become mainstream. The development of agricultural and forestry waste instead of a nonrenewable peat matrix as the substrate is an important direction for the future industry of potted peonies. However, the mechanism of the effects of different substrates on the growth and development of peonies remains unclear. In this experiment, “Luhehong”, a peony variety from Heze, Shandong Province, was selected as the main experimental material. The response mechanism of peony roots to different substrate proportions was analyzed using untargeted metabolomics of potted peonies. Results showed that the potential for pot growth of planted peonies using the mixed-straw mixing matrix (Matrix K) is better than that of the rice husk matrix (Matrix G) and the control matrix. Moreover, the comparative analysis of the metabolic groups indicates that the number of peony root secretions in the three matrices has a remarkable difference, possibly related to the nutrition supply levels of the peony roots, in the different matrices of adaptive response and adjustment. Furthermore, (2r)-3-hydroxyisovaleroylcarnitine, trigonelline, 2-acetylresorcinol, and dehydroascorbic acid (oxidized vitamin C)—four metabolites with the most substantial intergroup differences—are considered key metabolites. The metabolic pathway analysis of propanoate, and ascorbate and aldarate metabolism, and the two pathways related to an environmental response, namely, ABC transporters and phosphatidylinositol signaling system, indicated that these pathways were remarkably enriched. Both may be the key way to affect the growth and development of potted peonies. This study can provide an important reference for the rational allocation of the substrate of agricultural and forestry waste in potted peony cultivation and application. Full article

Tree peony (Paeonia suffruticosa Andr.), a unique traditional flower in China, is famous for its ornamental value, medical use, and edible oil production. Traditional propagation methods, such as sowing, dividing, and grafting do not allow the large-scale production of selected peony varieties. Therefore, the objective of our study is to evaluate an air-layering technique on the rooting success of three tree peony cultivars (‘Baoqing Hong’, ‘Quehao’, and ‘Xishi’). The experiments were established through consideration of the influence of the time of the year the rooting was performed (mid-May, mid-June, or mid-July) and the growth regulators (1-naphthaleneacetic acid-NAA and indole-3-butyric acid-IBA) applied at different concentrations (1000 mg/L, 1500 mg/L, 2000 mg/L). The results showed that the rooting rate was the highest when the air-layering time occurred in mid-June, and the rooting rate of ‘Quehao’ was found to be the most significant, reaching 100%. The rooting percentages of 82.86% and 77.14% were obtained for ‘Baoqing Hong’ and ‘Xishi’, respectively. The growth regulators affected the rooting performance of the three cultivars differently. The rooting parameters of ‘Quehao’ were negatively correlated with the concentration of NAA but positively correlated with IBA, whereas the ‘Baoqing Hong’ and ‘Xishi’ cultivars showed no dose dependence for the supplied growth regulators. Root number, root tip number, and maximum root length in ‘Quehao’ were higher than those of the other two cultivars. The conclusion of our study is that the air-layering technique is a suitable method for achieving satisfactory propagation of selected tree peony cultivars. Full article

Tree peony (Paeonia suffruticosa Andr.) is a famous ornamental and medicinal flowering species. However, few high-efficiency chloroplast microsatellite markers have been developed for it to be employed in taxonomic identifications and evaluation of germplasm resources to date. In the present study, a total of 139 cpSSR loci were identified across eleven tree peony plastomes. Dinucleotide repeat SSRs (97.12%) were most abundantly repeated for the AT motif (58.27%), followed by the TA motif (30.94%) and the TC motif (7.91%). Twenty-one primer pairs were developed, and amplification tests were conducted for nine tree peony individuals. Furthermore, 19 cpSSR markers were amplified on 60 tree peony accessions by a capillary electrophoresis test. Of 19 cpSSR markers, 12 showed polymorphism with different alleles ranging from 1.333 to 3.000. The Shannon’s information index and polymorphism information content values ranged from 0.038 to 0.887 (mean 0.432) and 0.032 to 0.589 (mean 0.268), respectively. The diversity levels for twelve loci ranged from 0.016 (at loci cpSSR-8 and cpSSR-26) to 0.543 (at locus cpSSR-15), averaging 0.268 for all loci. A total of 14 haplotypes (23.33%) were detected in the three populations. The haplotypic richness ranged from 0.949 to 1.751, with a mean of 1.233 per population. The genetic relationship suggested by the neighbor-joining-based dendrogram divided the genotypes into two clusters. The Jiangnan population was allotted to Cluster II, and the other two populations were distributed into both branches. These newly developed cpSSRs can be utilized for future breeding programs, population genetics investigations, unraveling the genetic relationships between related species, and germplasm management. Full article

In recent years, plant protein hydrolysates have gained increased attention due to their superior antioxidant activity and potential to prevent several chronic diseases associated with oxidative stress. This study aimed to investigate the antioxidant activity, functional properties, and cytoprotective effects of the tree peony seed protein hydrolysate (TPSPH) with different molecular weights (MWs). The antioxidant activities were evaluated by DPPH, hydroxyl radicals scavenging, Fe²⁺ chelating, and inhibition of the β-carotene oxidation abilities. The protective effects and mechanism against oxidative stress were determined using H₂O₂-stressed HepG2 cells. MW > 30 kDa of TPSPH showed the highest radical scavenging (DPPH IC₅₀ = 0.04, hydroxyl IC₅₀ = 0.89 mg/mL) and inhibition of β-carotene oxidation (80.07% at 2.0 mg/mL) activity. Moreover, MW > 30 kDa possessed high hydrophobicity, emulsifying capacity, and abundant antioxidant amino acids (28.22% of hydrophobic amino acids and 8.3% of aromatic amino acids). MW 5–10 kDa exhibited more effective protection against H₂O₂-induced HepG2 cells, by reducing reactive oxygen species (ROS), malonaldehyde (MDA), lactate dehydrogenase (LDH), and activating antioxidant enzymes (superoxide dismutase and catalase). These results indicated the potential application of TPSPH as an antioxidant in food and functional foods. Full article

Woody peony (Paeonia × suffruticosa Andr.) has many cultivars with genetic variances. The flower essential oil is valued in cosmetics and fragrances. This study was to investigate the chemical diversity of essential oils of eleven representative cultivars and their potential target network. Hydro-distillation afforded yields of 0.11–0.25%. Essential oils were analyzed by GC-MS and GC-FID which identified 105 compounds. Three clusters emerged from multivariate analysis, representative of phloroglucinol trimethyl ether (‘Caihui’), citronellol (‘Jingyu’, ‘Zhaofen’ and ‘Baiyuan Zhenghui’) and mixed (the rest of the cultivars) chemotypes. ‘Zhaofen’ and ‘Jingyu’ also exhibited low levels of other rose-related compounds. The main components were subjected to a target network approach. Drug-likeness screening gave 20 compounds with predictive blood–brain barrier permeation. Compound target network identified six key compounds, namely nerol, citronellol, geraniol, geranic acid, cis-3-hexen-1-ol and 1-hexanol. Top enriched terms in GO, KEGG and DisGeNET were mostly related to the central nervous system (CNS). Protein—protein interactions revealed a core network of 14 targets, 11 of which were CNS-related (targets for antidepressants, analgesics, antipsychotics, anti-Alzheimer’s and anti-Parkinson’s agents). This work provides useful information on the production of woody peony essential oils with specific chemotypes and reveals their potential importance in aromatherapy for alternative treatment of CNS disorders. Full article

Paeonia suffruticosa Andr. is a famous ornamental and aromatic plant with hundreds of cultivars in China. The objective of this work was to investigate comparative chemical profiles of essential oils and hydrolate extracts from eight P. suffruticosa Andr. cultivars from Central China. The percentages of hydrocarbons in hydrolate extracts (≤1.1%) were significantly lower than those in the essential oils (29.8–63.7%). The percentages of oxygenated compounds in hydrolate extracts (98.3–99.8%) were significantly higher than those in the essential oils (34.8–69.6%). Multivariate analyses with hierarchical clusters and principal components further indicated the chemical differences between essential oils and hydrolate extracts. Due to predominance of oxygenated compounds and almost trace level of hydrocarbons, P. suffruticosa Andr. hydrolate extracts could be good alternatives to the essential oils. Moreover, distribution of major oxygenated compounds in hydrolate extracts varied with cultivars. Hydrolate extracts from ’SHT’, ’WLPS’ and ’BXT’ presented chemotypes of methylated phenols (65.0%), 2-phenylethanol (64.4%) and geraniol + citronellol + nerol (59.9%), respectively. Those from five other cultivars presented somewhat mixed chemotypes. These results were further confirmed by quantitative evaluation relative to the major oxygenated compounds. The outcome of this work will promote applications of P. suffruticosa Andr. hydrolate extracts in fragrances and cosmetics. Full article