Aquaporins play an essential role in regulating transmembrane water transport in plants. Postharvest water loss often leads to wilting of cut flowers, significantly reducing their ornamental value and posing a major challenge for commercial production. Based on previous transcriptomic analysis, fourteen AQP genes were identified and classified into four subfamilies. Among them, PIPs were predominantly expressed in floral organs, TIPs showed high expression in petals, while NIPs and SIPs were mainly expressed in green tissues. During the vase life period, the expression patterns of IpPIP2-2 and IpTIP1-3 were closely associated with early flower opening. Cut flower stems were either subjected to postharvest water loss to levels of 5 % (WL5) or 10 % (WL10), or pretreated with the aquaporins inhibitor HgCl2 or the activator beta-Mercaptoethanol (beta-ME). Morphological traits, water status, and the expression of AQP genes in petals were evaluated throughout the vase life period. The results demonstrated that postharvest water loss accelerated flower opening and petal shedding, reduced flower diameter, and shortened vase life. In addition, water loss promoted petal ethylene synthesis and increased MDA accumulation, significantly accelerating petal senescence. beta-ME significantly improved water uptake and accelerated flower opening, whereas HgCl2 showed no significant inhibitory effect during the vase period. During the early stages of flower opening, WL10 and beta-ME treatments markedly upregulated the expression of IpPIP2-2 and IpTIP1-3. Furthermore, water loss elevated the expression of key genes involved in ethylene synthesis and signal transduction pathways. These findings suggest that postharvest water loss triggers upregulation of aquaporin genes IpPIP2-2 and IpTIP1-3, which facilitates rapid water uptake and ethylene release in petals during the initial vase period. This study provides valuable insights into potential strategies for improving the quality and longevity of Itoh peony cut flowers.

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.

Paeonia ostii 'Fengdan' is a multifunctional plant valued for its ornamental, medicinal, and edible properties. Its flowers emit a certain amount of volatile aromatic substances, showing potential applications in functional foods and natural fragrances. Selenium (Se) application can increase the Se content and nutrient quality of plant tissues. However, the impacts and mechanisms of Se application on the aroma substances of tree peony flowers remain largely elusive. In this study, 100 mg & sdot;L- 1 Na2SeO3 was sprayed approximately one week prior to flowering, and floral volatiles were collected at full bloom. The composition and content of volatile organic compounds (VOCs) and the expression of related genes were comprehensively analyzed by GC-MS, GC-IMS, PLS-DA, and RT-qPCR in tree peony flowers. GC-MS and GC-IMS identified 24 and 54 VOCs in tree peony flowers respectively, including terpenoids, alcohols, aldehydes, esters, benzenes, and alkanes. Se altered the composition and content of VOCs, especially increasing the release of key terpenoids such as beta-ocimene, 3,7-dimethyl-2,6octadien-1-ol, gamma-terpinene and linalool. PLS-DA analysis clearly distinguished the Se-treated samples from the control, with VIP scores identifying terpenoids as the major contributors. Moreover, the gene expression pattern revealed that Se upregulated the expression of five rate-limiting genes (PoDXR, PoMCT, PoCMK, PoHDS, and PoHDRS) in the MEP pathway and five downstream terpene synthase genes (PoTPS1, PoTPS2, PoTPS3, PoTPS4, and PoTPS8). These findings demonstrate that Se promotes floral terpene emission in tree peony by regulating the MEP pathway genes, offering new insights into enhancing floral quality in tree peony flowers.

As representatives of early-flowering herbaceous peony types, certain cultivars known as the ‘Coral’ series are highly prized in the global cut flowers market for their unique dynamic color transitions from orange-red (amber) to creamy yellow during the florescence and senescence periods. Despite their strong growth vigor and high commercial value, these cultivars face critical postharvest preservation challenges, most notably rapid petal abscission and short vase life. Previous studies have confirmed that postharvest quality deterioration of these peony cut flowers, including undesired color fading and accelerated senescence of petals, is closely associated with ethylene and ROS accumulation. To address these development impediments, systematic optimization of the entire industrial chain is essential. Proposed countermeasures include preharvest regulation of environmental conditions and cultivation practices to establish a foundation for quality formation, as well as postharvest strategies such as precise harvest timing, anti-ethylene treatments, and full cold-chain logistics. Meanwhile, simplifying the distribution system and optimizing terminal vase preservation techniques are also crucial to maintain postharvest quality. In the long term, promoting sustainable development of the global cut-flower industry will require breeding new germplasm with low ethylene sensitivity from a global perspective, continuously optimizing agronomic practices to overcome year-round supply constraints, and accelerating the application of intelligent technologies such as the Internet of Things (IoT) in full chain quality management.

An integrated preservation strategy combining ethylene inhibition and enhanced energy metabolism was developed to improve postharvest performance in Itoh peony 'Bartzella', a high-value cut flower with rapid petal abscission and short vase life following refrigerated transport. Harvested flowers were pulse-treated with 20 & micro;g L-1 Chrysal AVB for 2 h, stored at 4-6 degrees C for 10 d, then placed in preservative solution (PS) or deionized water. The AVB+PS combination extended the best viewing period by 12 h, increased maximum flower diameter by 1.4 cm, suppressed ethylene and respiration peaks, and maintained higher energy status and membrane integrity compared to controls. Additionally, this combination modulated the expression of genes involved in ethylene biosynthesis, signaling, and energy metabolism. These findings demonstrate that the dual strategy effectively preserves postharvest quality and offers commercial applicability for ethylene-sensitive cut flowers such as Itoh peony.

The off-season cultivation of potted tree peonies is gradually expanding in China and Japan. However, maintaining the growth of these plants in natural environments during spring and summer poses significant challenges after they have bloomed in a greenhouse. Under excess light energy, the leaves often exhibit severe chlorosis, reducing plant vigor and death in extreme cases. This study investigated the intense spring light photodamage effect between natural light (Control) and 40 % shading (shading) to rejuvenate potted tree peonies post-flowering. We determined that leaf morphology, chloroplast ultrastructure, photosynthetic performance, protective enzyme activities, and the expression of genes involved in chlorophyll biosynthesis and degradation by colorimeter, TEM, Portable Photosynthesis System, Spectrophotometric method, and qPCR methods, respectively. The results indicated that tree peony leaves displayed symptoms of chlorosis and yellowing, with damaged chloroplast ultrastructure, decreased chlorophyll content, and increased redness value (a*), leading to significant photooxidative bleaching effects under spring natural light conditions. However, shading reduced the accumulation of O2 & sdot; and H2O2, increased POD and CAT activities, and decreased MDA content in the leaves. The expression levels of magnesium chelatase subunits CHLI and CHLH (CHLI and CHLH), geranylgeranyl reductase (CHLP), chlorophyll b reductase (NYC1), and mg-dechelatase (SGR) genes were significantly higher under shading conditions than that of the early stage under natural light from greenhouse transported to the field. Shading maintained the redox homeostasis and ensured the structure stability of chloroplast, improving the photosynthetic capacity of tree peony leaves. Overall, the experimental results indicate that moderate shading can effectively reduce photooxidative damage, proving that moderate shading is an effective technical strategy that can be used for transferring potted peonies from greenhouse to field management after flowering.

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.

The use of the entomopathogenic fungus Metarhizium anisopliae is an important strategy for green control of plant pests. Metarhizium can also act as a plant endophyte to promote plant growth. In this paper, we verified the endophyticity of Metarhizium in the root system of ‘Fengdan’ tree peony (Paeonia ostii) by various means. And the growth-promoting effect of Metarhizium on the growth of tree peony seedlings was explored. The results showed that Metarhizium spores were able to attach to the surface of the tree peony root system in large numbers after 12 h of treatment; mycelium could be observed to colonize the young root cells after 60 d of treatment, and the designed Metarhizium ITS-specific sequences were able to observe clear specific bands in the tree peony root system. The application of 1 × 107 spores·mL−1 and 2 × 107 spores·mL−1 Metarhizium treatment groups elevated root indole-3-acetic acid (IAA) content by 13.9

Senescence-associated genes ( SAGs ) play a crucial role in regulating organ senescence in plant growth and development. However, their specific role in the florescence and senescence processes of cut peony flowers, particularly Itoh peonies, remains largely unclear. This study employed transcriptome analysis to investigate the expression patterns of IpSAG genes during the florescence and senescence of cut Itoh peony flowers in vases. Additionally, the function of IpSAG12 was examined using virus-induced gene silencing (VIGS) via vacuum infiltration to elucidate its role. The findings revealed that the opening and senescence of cut Itoh peonies in vases progress through three stages: early opening, middle transition, and later senescence. Notably, ethylene release followed a specific pattern, increasing sharply at the onset of flowering, then declining quickly during the early opening stage, displaying an ethylene-climacteric trait. Furthermore, the expression of the senescence- associated gene IpSAG12 was minimal during the opening and transition stages but significantly increased by 27.5 times during the senescence stage. Silencing IpSAG12 using VIGS extended the vase life of cut flowers by approximately 12 hours. This intervention resulted in a reduced electrolyte leakage rate, lower malondialdehyde (MDA) content, decreased ethylene release rate, reduced activity of 1-aminocyclopropane-1-carboxylic acid oxidase 1 (ACO1), and lower expression of IpACS1 and IpACO1 compared to the TRV control group. Conversely, the soluble protein content significantly increased in petals of the TRV- IpSAG12 group. Collectively, these findings suggest that IpSAG12 is a critical target gene in the ethylene signaling pathway that governs petal senescence in Itoh peonies.

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.

(1) Tree peony (Paeonia suffruticosa Andrews) is a woody ornamental plant originating from China, and beloved by people worldwide. Non-structural carbohydrates (NSCs) play a crucial role in regulating the flowering quality of tree peonies in both field and potted conditions. However, the effects of NSCs accumulation and allocation in various organs during the vegetative growth stage on the flowering quality of tree peony under forcing culture remains unclear. (2) Two-year-old grafted seedlings of tree peony cv. ‘Luoyanghong’ were subjected to orthogonal treatments to investigate the role of NSCs accumulation in plants’ developmental process. We measured leaf photosynthetic capacity, NSCs accumulation in the organs of seedlings, observed key ornamental characteristics of flowering quality under forcing culture conditions, and evaluated the qualities of seedlings and flowers using the seedling index (SI) and flowering index (FI), respectively. (3) There was a significant positive correlation between leaf photosynthetic capacity and NSCs accumulation in both the whole plant and roots of potted tree peony. Roots were identified as the primary organs for NSCs accumulation in potted tree peonies. Sufficient NSCs accumulation in the plant, particularly in the roots during the defoliation period, was essential not only for enhancing the seedling quality of potted tree peonies but also for improving the flowering quality under forcing culture conditions. Both the seedling index (SI) and flowering index (FI) exhibited a significant dose-response with increasing root NSCs accumulation at defoliation. The T3 group, which involved slight root pruning (by 25%), combined with a high-concentration rooting agent (750 mg·L−1) and Metarhizium anisopliae (20 million U·mL−1), resulted in the highest photosynthetic capacity, SI, FI and NSCs accumulation status (NSCAR), making it the optimal treatment combination. (4) This finding indicates that increasing NSCs accumulation in the roots of potted tree peonies is a crucial biological foundation for producing high-quality potted flowers under forcing culture conditions, which provide new insights into the importance of NSCs in tree peony flowering and may improve the production technology for high-quality potted tree peony flowers under forcing culture conditions.

Auxin gradient on either side of the abscission zone play a crucial role in regulating organ abscission during plant senescence. Yet, the impact of auxin on the opening and senescence of cut peony flowers, specifically Itoh peony 'Bartzella', remains elusive. We employed the frozen section method to investigate the cell morphology within the petal abscission zone. Additionally, we quantified auxin levels via enzyme immunoassay and assessed the expression of genes related to indole-3-acetic acid (IAA) levels. Through our analyses, we pinpointed the critical gene, IpAUX1. Further investigation of IpAUX1 involved virus-induced gene silencing (VIGS) and transient overexpression techniques, allowing us to assess its role both in vitro flowers, through vacuum application, and in vivo flowers, via injection. Significant alterations were observed in the structure and cell morphology of the abscission zone correlating with the process of petal abscission, alongside noticeable auxin gradient. Silencing IpAUX1 led to a noticeable delay in petal abscission for both in vitro flowers and vivo flowers, while its transient overexpression hastened this process. This silencing effect was accompanied by a reduction in IAA levels around the abscission zone and a subsequent delay in the erasure of the auxin gradient. It also resulted in the downregulation of several genes: the auxin response factor IpARF1, ethylene synthesis-related genes IpACS1 and IpACO1, and cell wall hydrolysis-related genes IpPME1 and IpPG1. Conversely, the expression of genes involved in auxin synthesis gene IpYUCCA10, auxin efflux carrier IpPIN1, and the ethylene receptor IpETR1 saw significant upregulation. This study concludes that the auxin influx carrier IpAUX1 enhances the abscission zone cells' responsiveness to ethylene by modulating the auxin gradient. This action promotes cell hydrolysis within the abscission zone, thereby encouraging petal abscission. Our findings underscore the pivotal role of IpAUX1 as a positive regulator during the process of petal abscission.

(1) Background: Tree peonies display extensive cultivar diversity due to widespread hybridization, resulting in a complex genetic architecture. This complexity complicates the selection of universal reference genes across different cultivars for qRT-PCR analyses. Paeonia suffruticosa ‘Doulv’, notable for its unique green blooms in China, exhibits chlorosis post-flowering and features petaloid stamens and pistils. (2) Methods: Based on published literature and RNA-seq data from ‘Doulv’, nine candidate reference genes—ACT (Actin), TUB (β-Tubulin), UBC (Ubiquitin Conjugating Enzyme), UBQ (Ubiquitin), UPL (Ubiquitin Protein Ligase), PP2A (Protein Phosphatase 2A), PP2C (Protein Phosphatase 2C), MBF1A (Multiprotein Bridging Factor 1A), and GAPDH (Glyceraldehyde-3-Phosphate Dehydrogenase)—were selected. Their expression stability was assessed across various tissues and developmental stages of ‘Doulv’ flowers using qRT-PCR, with evaluations conducted via GeNorm_v3.5, NormFinder_v20, and BestKeeper_v1.0. Gene cloning and expression analyses of PsCUC3, including its subcellular localization, were performed. (3) Results: GAPDH and ACT were identified as the most stable reference genes in petaloid stamens across various developmental stages of ‘Doulv’, whereas UBC and MBF1A were optimal across different tissues. Notably, specific conserved amino acids in PsCUC3 from ‘Doulv’ diverged from those in NAM/CUC3 proteins of other species, impacting its protein structure. PsCUC3 expression analysis revealed no correlation with chlorophyll content in petaloid stamens but an association with petaloid organ development. Furthermore, PsCUC3 was predominantly localized in the nucleus. (4) Conclusions: This study comprehensively evaluated suitable reference genes using GeNorm_v3.5, NormFinder_v20, and BestKeeper_v1.0 software, establishing a robust qRT-PCR detection system for ‘Doulv’ peony. These results provide a solid experimental foundation for further research on ‘Doulv’ peony. Building on this experimental foundation, the functional analysis of the PsCUC3 gene was conducted. The findings suggest a potential association between the PsCUC3 gene and floral morphology alterations in ‘Doulv’, identifying PsCUC3 as crucial for understanding the molecular mechanisms influencing floral structure in tree peonies.

In order to screen the reference genes of Itoh peony ‘Bartzella’, this study took the petals of ‘Bartzella’ cut flowers at different developmental stages as well as the root, stem, petiole, leaf, receptacle, sepal, petal, stamen and ovary as experimental materials. Combined with the existing ‘Bartzella’ transcriptomic data of our lab and conventional reference genes, ten candidate reference genes（GAPDH, ACT, UBQ,β-TUB, PP2A, CYP, EF-1α, F3H, TIP41, UBC） were screened out. Real-time quantitative PCR and geNorm,NormFinder, BestKeeper and RefFinder software were used for evaluation. The results showed that the double genes of UBQ and TIP41 were the best reference gene combination for the petals at different developmental stages of ‘Bartzella’ cut flowers. β-TUB, UBQ and ACT could be used as the best combination of reference genes for different organs of ‘Bartzella’ plant. Meanwhile, UBQ and TIP41 were used as double reference genes to analyze the expression patterns of five senescence related genes（ACS1, ACO1, ETR1,SAG12 and SAG21） of ‘Bartzella’ cut flower petals. The results showed that those five genes played an important role in the senescence process of Itoh peony ‘Bartzella’ cut flowers based on two double reference genes analysis. The combinations of selected internal reference genes laid an experimental foundation for further study on the differential expression of functional genes in the Itoh peony.

[目的]研究不同间伐强度对油用牡丹'凤丹'植株生长发育、不同冠层的光合性能、籽粒产量及油脂品质的影响,为油用牡丹人工林质量精准提升和可持续利用提供理论依据和技术支撑.[方法]以河南省沁阳市试验基地2013年10月定植的'凤丹'牡丹人工林为研究对象,初植密度为57000株·hm-2.2017年进入丰产期,果荚成熟后调查发现,高密条件下遮荫导致弱苗死亡,保有密度为46800株·hm-2,于2018年3月13日发芽后进行人工间伐,间伐强度为0％(CK)、17％(A)、35％(B)、47％(C)和62％(D).2019年测定植株的生长状况、冠层光合参数、产量性状等指标.[结果]1)间伐对'凤丹'植株的生长状况、光合特性、籽粒产量与品质均有显著影响(P<0.05).单株植株叶面积随间伐强度的增大依次比对照增加7.0％、11.9％、21.2％和25.1％.单株冠幅、开花数量、花径、新生叶片数、叶夹角、新生枝条数呈现相同的变化趋势,株高趋势则相反.2)叶片叶绿素、可溶性蛋白质含量、净光合速率(Pn)、SOD与CAT活性在冠层间表现为:上层>中层>下层,MDA含量表现趋势相反,间伐明显改善了'凤丹'冠层光能分布,提高了叶片的光合性能.3)单株结果数、单株籽粒数以及单株果荚质量随间伐强度的增大逐渐升高,百粒质量和籽粒产量呈先升高后降低的趋势,以间伐强度47％效果最好,比CK增产47.97％,显著高于其他处理(P<0.05).牡丹籽仁脂肪酸组份与含量没有显著差异,但总维生素E含量随着间伐强度呈现先增加后下降的过程,间伐强度47％的牡丹籽仁维生素E各组分与含量均高于其他处理,间伐后籽粒粗脂肪、淀粉和蛋白质含量均有显著改变.[结论]通过间伐降低油用牡丹的群体密度,能够调节群体条件下冠层光能分布、改善个体营养状况和降低空间竞争压力,保持油用牡丹高产稳产的生产性能,中等强度(47％)的间伐调控'凤丹'牡丹人工林群体结构的效果最好.间伐是调控'凤丹'牡丹群体光合性能和籽粒产量与品质的有效措施.

试验以牡丹'洛阳红'为材料,比较提早盆养后促成栽培(FCPP)和临时上盆直接促成栽培(FCT-PP)两种方式的盆花质量,以及硼砂灌根对其促成栽培的调控效应,以期为广州异地盆养牡丹年宵花生产提供理论依据和技术支持.结果表明,两种促成栽培方式均能实现广州异地盆养牡丹植株发育和开花,在未经硼砂灌根条件下,FCPP方式可以显著降低缩蕾率、缩短盆养期、延长单株最佳观赏期29.4 h,分别提高花径、花色素苷含量、叶绿素a和叶绿素b含量18.3％、36.6％、29.1％和29.4％,植株营养生长和生殖生长更协调,盆花质量显著提高.硼砂灌根处理显著提高牡丹根、叶、花中的硼素含量、蕾径、花瓣中花色素苷含量,以及花瓣的亮度、红度和饱和度.FCPP盆花质量明显优于FCTPP方式,以2.0 g/L硼砂灌根的效果较优.建议广州异地盆养牡丹年宵花生产时采用提早盆养后促成栽培的方式,并结合硼砂灌根,进一步提高促成栽培盆花的质量.

为了研究芍药ACS基因的功能,应用RACE技术从芍药切花品种桃花飞雪中克隆了PlACS基因cDNA序列,利用生物信息学方法对其编码的蛋白质进行了综合分析;以pET32a为骨架,构建了 PlACS基因的原核表达载体,建立了 P1ACS蛋白高效的原核表达体系.结果表明,PlACS cDNA全长1 752 bp(GenBank登录号JX512359),共编码492个氨基酸,具有7个保守结构域及活性位点K278;分子进化分析表明,PlACS和牡丹ACS亲缘关系最近;二级结构预测发现,PlACS蛋白由α-螺旋、β-折叠、β-转角和无规则卷曲组成,四者比例分别为40.04％,16.26％,6.91％和36.79％;同源建模显示,PlACS蛋白以同源二聚体形式存在.PlACS蛋白最佳诱导表达条件为基因工程菌菌体密度A600达0.2时,在菌液中加入终浓度为0.1 mmol/L的IPTG,在37℃诱导2 h.PlACS重组蛋白高效原核表达体系为后续通过变复性获得有生物学活性的PlACS蛋白及其酶学功能鉴定奠定基础.

Tree peony is the most popular and important ornamental plant in China and has many different flower types. Although many studies about tree peony cultivation have been published, the regulatory mechanism of floral organ identity has not been explored. Paeonia ostii 'Fengdan' is a typical single-flower variety, and many important tree peony cultivars in China originated from homoploid hybridization between 'Fengdan' and other Paeonia species. Peony tea made from 'Fengdan' has already been introduced to the market, and the quality and price of peony tea are closely related to the flower type of 'Fengdan'. This research cloned six floral organ identity genes in 'Fengdan', namely, PsAP1fd, PsAP2fd, PsAP3fd, PsPIfd, PsAGfd, and PsSEP 1fd. The bioinformatics analysis was performed, and results showed that all these genes encoded MADS-box proteins, except PsAP2fd, and PsAP2fd encoded an AP2 protein. Five MADS-box proteins encoded by these genes contained two conserved motifs: MADS-MEF2 and K-box domain PsSEP1fd was hydrophilic and stable, whereas the other five proteins were hydrophilic and unstable. The results of qRT-PCR displayed that PsAP1fd was mostly observed in the petals and sepals, and PsAP2fd was mostly found in the petals. PsAP3fd had strong expressions in the stamens and petals. The highest expression level of PsPIfd was observed in the petals, followed by that in the stamens. The highest expression level of PsAGfd was observed in the pistils, followed by that in the stamens. PsSEP1fd was mainly expressed in the pistils. These results showed that the ABCE model was effective in the flower type formation of 'Fengdan'. Our work would help reveal the molecular mechanism underlying flower type formation in 'Fengdan' and promote quality control for peony tea products.

伊藤牡丹'巴茨拉'是适合反季节盆花生产的优良品种.为探讨春节异地牡丹促成栽培中水溶肥调控盆栽'巴茨拉'开花效果,在茎伸长初期用0、0.8、1.2和1.6 g·L-1 均衡型水溶肥(N-P-K=20-20-20+TE)进行灌根处理,观察测定水溶肥对植株生长发育、开花质量及相关生理生化指标的影响.结果表明:(1)水溶肥灌根能显著促进盆栽'巴茨拉'各部器官的生长和养分积累.(2)随水溶肥浓度的增加,叶片叶绿素、可溶性蛋白质和可溶性糖含量以及花枝长度、粗度和花蕾直径随之增大,各器官中氮素和钾素营养水平亦呈现增加趋势;中高浓度(1.2 g·L-1和1.6 g·L-1)水溶肥条件下,花蕾直径分别比对照显著增大了 4.4％和7.7％(P＜0.05),使花促成栽培时间缩短了 4.45 d和2.65 d,最佳观赏期延长了 5.08 d和1.70 d.(3)中浓度水溶肥处理盛开期花朵最大,花朵直径和单株成花率分别比对照提高了 16.0％和13.5％(P＜0.05),并显著提高了花瓣中类黄酮、类胡萝卜素含量及色彩黄度(P＜0.05).研究发现,适宜浓度的水溶肥能够显著提高'巴茨拉'促成栽培过程中枝叶花的协调性,使用水溶肥应成为'巴茨拉'盆花生产的基础管理措施;反季节栽培伊藤牡丹'巴茨拉'建议使用1.2 g·L-1均衡型水溶肥进行灌根.

We measured the morphological index, nutritional composition and the expression analysis of key genes during grain development of Paeonia suffruticosa cv. 'Fengdan' grown at altitudes of 100, 650 and 1010 m in Luo-yang. The aim of this study was to examine differences in grain yield traits and the transformation of soluble sugar, starch, soluble protein and fatty acid contents, as well as the related enzyme activity and differential expression of key genes in oil metabolism. The results showed that grain yield traits increased with altitudes and that the growth period of grain at the higher altitudes was longer than that at low and mid altitudes. The soluble sugar and starch in mature grains increased with altitudes, while soluble protein and crude fat did not change. During grain development, the activities of sucrose synthase (SS) and sucrose phosphate synthase (SPS) first decreased and then increased, with the lowest occurred at 90 d after flowering. The activities of pyruvate dehydrogenase (PDH), glutamic-pyruvic transaminase (GPT) and glutamic-oxalacetic transaminease (GOT) increased rapidly during 50-90 d after flowering and peaked at 90 d. The relative expression of acetyl-CoA carboxylase (ACCase) and stearoyl-ACP desaturase (SAD) peaked at 50 d after flowering, and ω-6 fatty acid desaturase 2 (FAD2) peaked at 90 d, in oil tree peony grain at different altitudes. There was a negative correlation of soluble sugar and starch with the accumulation of soluble protein and crude fat. SPS activity was positively correlated with the contents of soluble sugar and starch, and negatively correlated with the contents of soluble protein and crude fat during grain development. Activities of GPT and GOT were negatively associated with the content of soluble sugar and the content of starch, and had a highly significant positive correlation with the contents of soluble protein and crude fat. Activity of PDH was positively correlated with the content of soluble proteins and activities of GPT and GOT, and negatively correlated with the contents of soluble sugar and starch. It suggested that nutrient accumulation in the process of grain development of tree peony was transformed from sugar to crude fat and protein, and that metabolic enzymes, such as SPS, PDH, GPT and GOT, played an important role in this process. Palmitate acid, stearic acid and linoleic acid were negatively correlated with the relative increment of α-linolenic acid, indicating that fatty acid desaturation process in the grain development of tree peony was towards the direction of α-linolenic acid synthesis. The relative expression of ACCase, SAD, and FAD2 was positively correlated with the relative increment of α-linolenic acid accumulation, which played an important role in α-linolenic acid synthesis. The oil quality of tree peony grain was relatively stable at different altitudes, but grain production increased with altitude. Planting oil tree peony at mid to high altitudes could be an important strategy for the efficient use of marginal land in Luoyang.