Disrupting the olfactory response in Monochamus saltuarius: Two potential target genes for controlling the vector insect of pine wilt disease.

Worldwide, pine forests have been threatened by a devastating pine wood disease caused by Bursaphelenchus xylophilus, with Monochamus saltuarius being a newly recorded vector of the disease in Northeast China. The olfactory system plays important roles in both feeding and oviposition during the adult stage of M. saltuarius, and olfactory gene function research is essential for gaining an understanding of the olfactory mechanisms of this pest. However, there is limited information available regarding olfactory gene functions in this pest. In the present study, we selected 7 olfactory genes, including 2 chemosensory proteins, 2 odorant-binding proteins, the odorant co-receptor and 2 odorant receptors, which were relatively highly expressed during the adult stage. We silenced these genes by RNA interference (RNAi), and real-time quantitative PCR was used to detect their expression levels after double-stranded RNA (dsRNA) injection. The results indicate that these genes were significantly downregulated at 2 d post-dsRNA injection, and this was sustained until 5 d post-injection. Electroantennography tests indicated that the knockdown of MsalOBP14 and MsalOrco impaired the olfactory response of M. saltuarius to 11 host volatiles and 1 sex pheromone compound. Y-tube experiments further confirmed that downregulated MsalOBP14 and MsalOrco expression led to olfactory dysfunction in M. saltuarius, which significantly lost selectivity. The results indicate that MsalOBP14 and MsalOrco play critical roles in sex communication and host volatile detection in M. saltuarius, and possibly represent 2 effective targets for controlling this forest pest through olfactory disruption.

Role of comammox bacteria in granular bioreactor for nitrogen removal via partial nitritation/anammox.

In this study, two bioprocess models were first constructed with the newly-discovered comammox process described as one-step and two-step nitrification and evaluated against relevant experimental data. The validated models were then applied to reveal the potential effect of comammox bacteria on the granular bioreactor particularly suitable for undertaking partial nitritation/anammox (PN/A) under different operating conditions of bulk dissolved oxygen (DO) and influent NH4+. The results showed although comammox bacteria-based PN/A could achieve > 80.0 % total nitrogen (TN) removal over a relatively wider range of bulk DO and influent NH4+ (i.e., 0.25-0.40 g-O2/m3 and 470-870 g-N/m3, respectively) without significant nitrous oxide (N2O) production (< 0.1 %), the bulk DO should be finely controlled based on the influent NH4+ to avoid the undesired full nitrification by comammox bacteria. Comparatively, conventional ammonium-oxidizing bacteria (AOB)-based PN/A not only required higher bulk DO to achieve > 80.0 % TN removal but also suffered from 1.7 %∼2.8 % N2O production.

Enhanced sludge granulation and stable performance of an anammox expanded granular sludge bed (EGSB) reactor through the utilization of hydroxyapatite (HAP) particles.

The reuse of hydroxyapatite particles (HAPs) as a granulation activator for anammox sludge was explored to address the remaining issues of time-consuming and unstable granular structure in anammox granulation. During the granulation, nitrogen removal capacity from 2.8 to 13.7 gN/L/d was obtained within 193 days, accompanied by an enhancement in bio-activity from 0.23 to 0.52 gN/gVSS/d. HAPs and anammox microorganisms coupled well to aggregate into granules for denser biomass, higher settleability, and stronger mechanical properties, which effectively improved the biomass retention capacity and structural strength of the sludge system. A skeleton structure formed by the HAPs was characterized during the transformation of the granules, playing a crucial role in strengthening the stability of the sludge. The intermediate processes of granulation were thus clarified to propose an evolutionary pathway for anammox-HAP granules. The pre-addition of HAPs is conducive to achieving faster anammox granulation and rapid process start-up for high-strength wastewater treatment.

Screening and Identification of Soil Selenium-Enriched Strains and Application in Auricularia auricula.

Selenium (Se) is an essential trace element for human physiological metabolism. The application of organic Se as a source to cultivate Se-rich plants for micronutrient supplementation has been receiving increasing attention. In our study, a bacterial strain named H1 was isolated from the soil in Heilongjiang Province, China, and under optimal culture conditions, the unit Se content could reach 3000 µg·g-1 and its 16S ribosomal DNA sequence seemed to be a new molecular record of an Enterobacter species. After the domestication of Se tolerance and Se-rich experiments, H1 can be used as a Se source for cultivation of Se-rich Auricularia auricula. The results showed that soluble protein, soluble sugar, free amino acid and vitamin C contents in Auricularia auricula were notably increased by 28.7%, 21.8%, 32.5% and 39.2% under the treatment of Se concentration of 0.24 mg·kg-1, respectively. These findings enhance our understanding that H1 is more conducive to Se uptake and nutrient accumulation.

Nanoparticles targeting the adenosine pathway for cancer immunotherapy.

Cancer immunotherapy, as an emerging approach to cancer treatment, has tremendous potential for application. Compared to traditional methods such as surgery, chemotherapy, and radiation therapy, it has the ability to restore the patient's immune system, leading to long-term immune memory with less damage to normal tissues. However, immunotherapy has its limitations, including limited therapeutic efficacy, restricted patient populations, and inconsistent treatment responses. Finding effective immunotherapeutic approaches has become a key focus of its clinical application. The adenosine pathway is a recently discovered tumor immune regulatory signaling pathway. It can influence the metabolism and growth of tumor cells by acting through key enzymes in the adenosine pathway, thereby affecting the development of tumors. Therefore, inhibiting the adenosine pathway is an effective cancer immunotherapy. Common adenosine pathway inhibitors include small molecules and antibody proteins, and extensive preclinical trials have demonstrated their effectiveness in inhibiting tumor growth. The short half-life, low bioavailability, and single administration route of adenosine pathway inhibitors limit their clinical application. With the advent of nanotechnology, nano-delivery of adenosine pathway inhibitors has addressed these issues. Compared to traditional drugs, nano-drugs extend the drug's circulation time and improve its distribution within the body. They also offer targeting capabilities and have low toxic side effects, making them very promising for future applications. In this review, we discuss the mechanism of the adenosine pathway in tumor immune suppression, the clinical applications of adenosine pathway inhibitors, and nano-delivery based on adenosine pathway inhibitors. In the final part of this article, we also briefly discuss the technical issues and challenges currently present in nano-delivery of adenosine pathway inhibitors, with the hope of advancing the progress of adenosine inhibitor nano-drugs in clinical treatment.

Carbon flow, energy metabolic intensity and metagenomic characteristics of a Fe (III)-enhanced anerobic digestion system during treating swine wastewater.

Deep treatment and bioenergy recovery of swine wastewater (SW) are beneficial for constructing a low-carbon footprint and resource-recycling society. In this study, Fe (III) addition from 0 to 600 mg/L significantly increased the methane (CH4) content of the recovered biogas from 61.4 ± 2.0 to 89.3 ± 2.0 % during SW treatment in an anaerobic membrane digestion system. The specific methane yields (SMY) also increased significantly from 0.20 ± 0.05 to 0.29 ± 0.02 L/g COD. Fe (III) and its bio-transformed products which participated in establishing direct interspecific electron transfer (DIET), upregulated the abundance of e-pili and Nicotinamide adenine dinucleotide (NADH), enriched electroactive bacteria. The increase in cellular adenosine triphosphate (cATP) from 6583 to 14,518 ng/gVSS and electron transport system (ETS) from 1468 to 1968 mg/(g·h) promoted the intensity of energy flow and electron flow during anaerobic digestion of SW. Moreover, Fe (III) promoted the hydrolysis and acidification of organic matters, and strengthened the acetoacetic methanogenesis pathway. This study established an approach for harvesting high quality bioenergy from SW and revealed the effects and mechanisms from the view of carbon flow, energy metabolic intensity and metagenomics.

Metabolite Profiling and Biological Activity Assessment of Paeonia ostii Anthers and Pollen Using UPLC-QTOF-MS.

Paeonia ostii is an important economic oil and medicinal crop. Its anthers are often used to make tea in China with beneficial effects on human health. However, the metabolite profiles, as well as potential biological activities of P. ostii anthers and the pollen within anthers have not been systematically analyzed, which hinders the improvement of P. ostii utilization. With comprehensive untargeted metabolomic analysis using UPLC-QTOF-MS, we identified a total of 105 metabolites in anthers and pollen, mainly including phenylpropanoids, polyketides, organic acids, benzenoids, lipids, and organic oxygen compounds. Multivariate statistical analysis revealed the metabolite differences between anthers and pollen, with higher carbohydrates and flavonoids content in pollen and higher phenolic content in anthers. Meanwhile, both anthers and pollen extracts exhibited antioxidant activity, antibacterial activity, α-glucosidase and α-amylase inhibitory activity. In general, the anther stage of S4 showed the highest biological activity among all samples. This study illuminated the metabolites and biological activities of anthers and pollen of P. ostii, which supports the further utilization of them.

Interspecies electron transfer and microbial interactions in a novel Fe(II)-mediated anammox coupled mixotrophic denitrification system.

This study effectively coupled anammox and mixotrophic denitrification at a high nitrogen load rate of 6.84 g N/L/d with 40 mg/L Fe(II). Fe(II) enhanced the activity of nitrate reductase, nitrite reductase, and hydrazine dehydrogenase enzymes, facilitating accelerated ATP synthesis. Through electrochemical experiments, interspecies electron transfer processes in coupled system were explored. Fe(II) promoted flavin mononucleotide secretion, enhancing electron-donating and electron-accepting capacity by 2.8 and 1.3 times, respectively. Fe(II) triggered the enrichment of autotrophic denitrifying bacteria (Azospira and Hydrogenophaga), transitioning from single organic nutrient to mixotrophic denitrification. Meanwhile, Fe(II) increased Candidatus_Kuenenia abundance from 35.2 % to 49.0 %, establishing the competitive advantage of anammox bacteria over completed denitrifying bacteria (Comamonas). The synergistic interactions between anammox and various denitrification pathways achieved a nitrogen removal rate of 5.88 g N/L/d, with anammox contribution rate of 88.3 %. This study provides insights into broadening the application of partial denitrification /anammox and electron transfer in multi-bacterial coupling systems.

A Set of Artificial Pollination Technical Measures: Improved Seed Yields and Active Ingredients of Seeds in Oil Tree Peonies.

The tree peony, a novel woody oil crop extensively cultivated in China, necessitates further investigation into artificial pollination technology to enhance seed yield. In this study, we conducted artificial pollination experiments with 6-year-old Paeonia ostii 'Feng Dan' seedings for suitable pollen sources, pollen concentration, pollination timing, and pollination frequency. By evaluating seed yields, active ingredients, and oil quality, we derived the following significant conclusions. Firstly, compared to natural pollination, artificial pollination could significantly increase the fruit diameter by 13.94-27.58%, seed yields by 35.17-58.99%, and oil content by 6.45-7.52% in tree peonies. In active ingredients, seeds produced by pollen from Hantai County significantly enhanced starch content (by 48.64%), total phenols (by 41.18%) and antioxidant capacity (by 54.39%). In oil quality, seeds produced by pollen from Heyang County exhibited the highest α-linolenic acid and total fatty acid content with enhancements of 1.68%, 7.41%, and 8.48%. Secondly, hand pollination with pure pollen significantly increased seed yield by 58.99%, total phenol content by 40.97%, antioxidant capacity by 54.39%, and oil content by 1.53% compared to natural pollination. Thirdly, pollination at 2/3 bloom range significantly increased seed number by 63.08% and yield by 45.61% compared to natural pollination. Finally, the effect of one, two, and three pollination events had no difference in seed yield. So, to summarize, applying a 100% concentration of allochthonous pollen once is recommended when the bloom range is more than two thirds.

Which horticultural activities are more effective for children's recovery from stress and mental fatigue? A quasi-experimental study.

Introduction: Studies have established the benefits of horticultural therapy and activities for human health and well-being. Nonetheless, limited research has been conducted on the potential restorative advantages and distinctions between different types of horticultural activities in terms of stress reduction. Methods: This study employed a quantitative research method to investigate the stress recovery benefits of five horticultural activities (flower arrangement, sowing and transplanting seeds, kokedama crafting, pressed flower card making, and decorative bottle painting with dried flowers) and one reference activity (short composition writing) for children. The experiment was conducted in a children's activity center's multi-purpose classroom with 48 elementary students aged 9-12 years. The subjects first took a stress test to induce stress and then engaged in horticultural activities for 20 min. Physiological stress was assessed using electrocardiograms and electroencephalograms as feedback indicators. Psychological and emotional changes were determined using the Positive and Negative Affect Schedule for Children and Self-Assessment Manikin scales. Results: The results demonstrated that horticultural activities greatly reduced physiological fatigue, and their recovery benefits were significantly greater than those of the reference activity. The recovery effects from different horticultural activities were similar across physiological indicators, although flower arrangement and sowing and transplanting seeds exhibited relatively robust recovery benefits. The heart rate and α-EEG-based generalized estimating equation revealed that horticultural activities offered significantly better relative recovery at each time phase of operation than the reference activity, with girls showing a 3.68% higher relative recovery value than boys. Flower arrangement and kokedama crafting offered better physiological recovery for students with prior horticultural experience, and these two activities received the highest scores in terms of positive effects and the "pleasure" dimension. Students believed that participating in horticultural activities resulted in a noteworthy increase in personal confidence and a greater sense of achievement. Conclusion: The study suggests that horticultural activities that involve real and vibrant plants or natural materials and are more attractive have more stress-relieving benefits. We conclude that horticultural activities are beneficial leisure activities that aid in stress relief for children and that it is important to consider the attributes of activities when developing horticultural programs for elementary students.

Transcriptome and volatile compounds analyses of floral development provide insight into floral scent formation in Paeonia lactiflora 'Wu Hua Long Yu'.

Herbaceous peony (Paeonia lactiflora) is a well-known ornamental plant in China, celebrated for its beautiful flowers that can emit fragrances. However, exact molecular mechanisms governing synthesis of floral volatiles within herbaceous peony remain unclear. To address this gap in knowledge, our study focused on analyzing the transcriptome and the levels of floral volatile compounds in P. lactiflora 'Wu Hua Long Yu' at different stages of flower development. Using gas chromatography-mass spectrometry (GC-MS), we obtained eighteen major volatile compounds, with monoterpenes being the dominant components among them. Our transcriptome analysis, based on pooled sequencing data, revealed the most differentially expressed genes (DEGs) existed between stages S1 and S3 of flower development. Among these DEGs, we identified 89 functional genes associated with the synthesis of volatile monoterpenes, with 28 of these genes showing a positive correlation with the release of monoterpenes. Specifically, key regulators of monoterpene synthesis in herbaceous peony appear to be 1-deoxy-D-xylulose 5-phosphate synthase (DXS), geranyl pyrophosphate synthase (GPPS), and terpene synthase (TPS). Additionally, our study identified some transcription factors (TFs) that may be involved in the biosynthesis of monoterpenes. These discoveries offer invaluable illumination into the intricate molecular underpinnings orchestrating the generation of floral fragrances in herbaceous peonies, and they offer a foundation for further research to identify and utilize candidate gene resources for this purpose.

The Development of the Stress-Free Polishing System Based on the Positioning Error Analysis for the Deterministic Polishing of Jet Electrochemical Machining.

Deterministic polishing based on jet electrochemical machining (Jet-ECM) is a stress-free machining method for low-rigidity and ultra-precision workpieces. The nozzle is equivalent to a special tool in deterministic polishing, and the workpiece material is removed using the mechanism of electrochemical dissolution at the position where the nozzle passes. By precisely regulating the nozzle's movement speed and dwell time, the quantity of material removed from the workpiece at a designated position can be finely adjusted. With this mechanism, the improvement of the workpiece shape accuracy can be achieved by planning the nozzle trajectory and nozzle movement speed. However, due to the positioning errors of the polishing device, the actual position of the nozzle may deviate from the theoretical position, resulting in errors in material removal amount, which affects the accuracy and stability of the polishing process. This study established a mathematical model to analyze the influence of nozzle positioning errors in deterministic polishing based on Jet-ECM. This model has been used to design a specific deterministic polishing device based on Jet-ECM. With the proposed deterministic polishing device, the surface shape of the workpiece is converged. The surface peak-to-valley (PV) value of the φ 50 mm workpiece (valid dimensions = 90% of the central region) indicated that the shape error of the surface was reduced from 2.67 µm to 1.24 µm in 34 min. The power spectral density (PSD) method was used to evaluate the height distribution and height characteristics of the workpiece surface. The results show that the low frequency spatial error is reduced significantly after processing. This study improves the accuracy of the stress-free deterministic polishing methods and further expands the use of deterministic polishing in industry.

Refracture-related bone transport of tibia: technical notes and preliminary clinical results in nineteen cases.

PURPOSE: Refracture is one of the main complications of bone transport, which brings additional physical and mental burden to surgeries and patients. We aimed to raise a new classification system of refracture-related bone transport based on the Simpson classification and to present our experience on treatment. METHODS: This retrospective analysis included 19 patients with refracture-related bone transport (average age of 37.7 years; 18 men). We developed a modified Simpson classification system to assist decision-making (conservative versus surgical). The ASAMI criteria were used to assess the outcomes at last follow-up. RESULTS: The mean follow-up was 12.3 ± 3.2 months. Complete union was achieved in all patients, with no reinfection. Based on the modified Simpson classification, refracture was Ia type (within regeneration area) in three cases, Ib (collapsed fracture at the regeneration area) in one case, Ic (stress fracture) in three cases, II (at the junction between the regenerate and original bone) in one case, III (at the docking site) in nine cases, and V (at distant site) in two cases. Refracture was managed conservatively in six cases and surgically in 13 cases. Average time to bone union was 2.8 ± 1.2 months in the conservative group versus 4.4 ± 1.4 months in the surgery group. Assessment at the final follow-up using the ASAMI criteria revealed excellent bone result in all patients, excellent functional results in six patients (31.6%), and good functional results in 13 patients. CONCLUSIONS: The modified Simpson classification could include refracture at the docking site and stress fracture in the regeneration zone and provide some guidance in determining the appropriate treatment strategy.

The integrate profiling of single-cell and spatial transcriptome RNA-seq reveals tumor heterogeneity, therapeutic targets, and prognostic subtypes in ccRCC.

Clear-cell renal cell carcinoma (ccRCC) is the most common type of RCC; however, the intratumoral heterogeneity in ccRCC remains unclear. We first identified markers and biological features of each cell cluster using bioinformatics analysis based on single-cell and spatial transcriptome RNA-sequencing data. We found that gene copy number loss on chromosome 3p and amplification on chromosome 5q were common features in ccRCC cells. Meanwhile, NNMT and HILPDA, which are associated with the response to hypoxia and metabolism, are potential therapeutic targets for ccRCC. In addition, CD8+ exhausted T cells (LAG3+ HAVCR2+), CD8+ proliferated T cells (STMN+), and M2-like macrophages (CD68+ CD163+ APOC1+), which are closely associated with immunosuppression, played vital roles in ccRCC occurrence and development. These results were further verified by whole exome sequencing, cell line and xenograft experiments, and immunofluorescence staining. Finally, we divide patients with ccRCC into three subtypes using unsupervised cluster analysis. and generated a classifier to reproduce these subtypes using the eXtreme Gradient Boosting algorithm. Our classifier can help clinicians evaluate prognosis and design personalized treatment strategies for ccRCC. In summary, our work provides a new perspective for understanding tumor heterogeneity and will aid in the design of antitumor therapeutic strategies for ccRCC.

Recent Advances in Nanomaterials for the Treatment of Acute Kidney Injury.

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

An optimized approach for solar concentrating parabolic dish based on particle swarm optimization-genetic algorithm.

Parabolic dish concentrators have demonstrated the highest thermal and optical efficiencies among the available concentrator options. This paper proposes a novel design approach for fabricating large parabolic dish concentrators by employing compliant petals optimized through Particle Swarm Optimization-Genetic Algorithm (PSO-GA). The design concept involves using cables to pull the outer corners of the petals towards the center, resulting in the creation of finely formed dish mirrors. These mirrors are constructed from thin, optimal-shaped metal petals with highly reflective surfaces. In addition, an analytical model is presented to optimize the bending stiffness of the petals by strategically arranging punched holes using PSO-GA. The proposed design concept is validated through the application of Finite Element Analysis and ray tracing software, specifically LightTools, as well as laboratory experiments. Based on the demonstration with a 1m-diameter parabolic dish, it was observed that a receiver surface with a radius of 3.5 cm could achieve an impressive sunlight collection efficiency of up to 98%. This innovative design approach offers several advantages, including simplified fabrication and transportation of flat mirror elements to field sites, which can potentially lead to cost reductions and highly efficient solar energy solutions.

The tree peony DREB transcription factor PrDREB2D regulates seed α-linolenic acid accumulation.

α-Linolenic acid (ALA), an essential fatty acid (FA) for human health, serves as the precursor of 2 nutritional benefits, docosahexaenoic acid and eicosapentaenoic acid, and can only be obtained from plant foods. We previously found that phospholipid:diacylglycerol acyltransferase 2 (PrPDAT2) derived from ALA-rich tree peony (Paeonia rockii) can promote seed ALA accumulation. However, the regulatory mechanism underlying its promoting effect on ALA accumulation remains unknown. Here, we revealed a tree peony dehydration-responsive element binding transcription factor, PrDREB2D, as an upstream regulator of PrPDAT2, which is involved in regulating seed ALA accumulation. Our findings demonstrated that PrDREB2D serves as a nucleus-localized transcriptional activator that directly activates PrPDAT2 expression. PrDREB2D altered the FA composition in transient overexpression Nicotiana benthamiana leaves and stable transgenic Arabidopsis (Arabidopsis thaliana) seeds. Repressing PrDREB2D expression in P. rockii resulted in decreased PrPDAT2 expression and ALA accumulation. In addition, PrDREB2D strengthened its regulation of ALA accumulation by recruiting the cofactor ABA-response element binding factor PrABF2b. Collectively, the study findings provide insights into the mechanism of seed ALA accumulation and avenues for enhancing ALA yield via biotechnological manipulation.

CircCDYL Contributes to Apoptosis, Ferroptosis, and Oxidative Stress of Ang II-Induced Vascular Smooth Muscle Cells in Thoracic Aortic Aneurysm.

Circular RNAs (circRNAs) have important regulation in thoracic aortic aneurysm (TAA). The function and mechanism of circCDYL (circ_0008285) was explored in TAA here. Angiotensin II (Ang II) was used to construct a TAA model. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed for the detection of circCDYL, miR-1270, and a disintegrin and metalloproteinase 10 (ADAM10). Cell viability was examined via cell counting kit-8 (CCK-8) assay and proliferation was analyzed using Ethynyl-2'-deoxyuridine (EdU) assay. Apoptosis rate was assessed via flow cytometry. Western blot was used for protein detection. Oxidative stress was evaluated by commercial kits. CircCDYL was upregulated in TAA tissues and Ang II-induced circCDYL upregulation in vascular smooth muscle cells (VSMCs). Knockdown of circCDYL weakened Ang II-aroused inhibition of viability, proliferation, and promotion of apoptosis, ferroptosis, and oxidative stress in VSMCs. CircCDYL served as a miR-1270 sponge. The mitigated regulation of circCDYL knockdown for Ang II-induced injury was restored after miR-1270 downregulation. CircCDYL positively regulated ADAM10 through interacting with miR-1270. Overexpression of miR-1270 abated Ang II-induced injury by downregulating ADAM10. In conclusion, circCDYL was involved in the Ang II-induced VSMC injury in TAA via the miR-1270/ADAM10 axis.

Abscisic acid-induced transcription factor PsMYB306 negatively regulates tree peony bud dormancy release.

Bud dormancy is a crucial strategy for perennial plants to withstand adverse winter conditions. However, the regulatory mechanism of bud dormancy in tree peony (Paeonia suffruticosa) remains largely unknown. Here, we observed dramatically reduced and increased accumulation of abscisic acid (ABA) and bioactive gibberellins (GAs) GA1 and GA3, respectively, during bud endodormancy release of tree peony under prolonged chilling treatment. An Illumina RNA sequencing study was performed to identify potential genes involved in the bud endodormancy regulation in tree peony. Correlation matrix, principal component, and interaction network analyses identified a downregulated MYB transcription factor gene, PsMYB306, the expression of which positively correlated with 9-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (PsNCED3) expression. Protein modeling analysis revealed 4 residues within the R2R3 domain of PsMYB306 to possess DNA binding capability. Transcription of PsMYB306 was increased by ABA treatment. Overexpression of PsMYB306 in petunia (Petunia hybrida) inhibited seed germination and plant growth, concomitant with elevated ABA and decreased GA contents. Silencing of PsMYB306 accelerated cold-triggered tree peony bud burst and influenced the production of ABA and GAs and the expression of their biosynthetic genes. ABA application reduced bud dormancy release and transcription of ENT-KAURENOIC ACID OXIDASE 1 (PsKAO1), GA20-OXIDASE 1 (PsGA20ox1), and GA3-OXIDASE 1 (PsGA3ox1) associated with GA biosynthesis in PsMYB306-silenced buds. In vivo and in vitro binding assays confirmed that PsMYB306 specifically transactivated the promoter of PsNCED3. Silencing of PsNCED3 also promoted bud break and growth. Altogether, our findings suggest that PsMYB306 negatively modulates cold-induced bud endodormancy release by regulating ABA production.

Integrated Metabolomics Approach Reveals the Dynamic Variations of Metabolites and Bioactivities in Paeonia ostii 'Feng Dan' Leaves during Development.

Paeonia ostii 'Feng Dan' is widely cultivated in China for its ornamental, medicinal, and edible properties. The whole plant of tree peony is rich in bioactive substances, while the comprehensive understanding of metabolites in the leaves is limited. In this study, an untargeted metabolomics strategy based on UPLC-ESI-TOF-MS was conducted to analyze the dynamic variations of bioactive metabolites in P. ostii 'Feng Dan' leaves during development. A total of 321 metabolites were rapidly annotated based on the GNPS platform, in-house database, and publications. To accurately quantify the selected metabolites, a targeted method of HPLC-ESI-QQQ-MS was used. Albiflorin, paeoniflorin, pentagalloylglucose, luteolin 7-glucoside, and benzoylpaeoniflorin were recognized as the dominant bioactive compounds with significant content variations during leaf development. Metabolite variations during the development of P. ostii 'Feng Dan' leaves are greatly attributed to the variations in antioxidant activities. Among all tested bacteria, the leaf extract exhibited exceptional inhibitory effects against Streptococcus hemolytis-ß. This research firstly provides new insights into tree peony leaves during development. The stages of S1-S2 may be the most promising harvesting time for potential use in food or pharmaceutical purposes.