Implementation of a Smart Teaching and Assessment System for High-Quality Cardiopulmonary Resuscitation.

The purpose of this study is to develop a smart training and assessment system called SmartCPR, for teaching and training cardiopulmonary resuscitation (CPR), based on human posture estimation techniques. In this system, trainees can automatically recognize and evaluate whether chest compressions during CPR meet the standard of high-quality CPR by simply using a device such as a smart phone. Through the system, trainees are able to obtain real-time feedback on the quality of compressions so that they can adjust the cycle, depth, frequency, and posture of compressions to meet the standard of high-quality CPR. In addition, the SmartCPR system is convenient for CPR trainers. Trainers can instantly and accurately assess whether the trainee's compressions meet the standard of high-quality CPR, which reduces the risk of manual assessment errors and also reduces the trainer's teaching pressures. Therefore, the SmartCPR system developed in this study can be an important tool for CPR teaching and training for physicians, which can provide training and guidance for high-quality CPR maneuvers and enable trainees to become more proficient in CPR and self-training.

Comparative metabolomics profiling reveals the unique bioactive compounds and astringent taste formation of rosehips.

Rosehips are a prominent source of numerous bioactive compounds. However, despite their extensive potential, the metabolic profiles among different rosehip species have not been fully elucidated. In this study, 523 secondary metabolites from rosehips of 12 Rosa species were identified using ultra-high-performance liquid chromatography-tandem mass spectrometry. They were primarily composed of flavonoids and phenolic acids. A K-means analysis revealed the characteristic metabolites in different rosehips. For example, R. persica contained a more abundant supply of phenolic acids, while R. roxburghii harbored a richer array of terpenoids. A total of 73 key active ingredients were screened from traditional Chinese medicine databases, and they indicated that R. persica is more promising for use in functional foods or health supplements compared with the other fruits. Moreover, a differential analysis identified 47 compounds as potential contributors to the astringent taste of rosehips, including ellagic acid 4-O-glucoside and cadaverine. This study provides valuable information to develop new functional foods of rosehips and improve the quality of their fruits.

The Marssonina rosae effector MrSEP43 suppresses rose immunity by targeting the orphan protein RcBROG.

Rose black spot disease, caused by Marssonina rosae (syn. Diplocarpon rosae), is one of the most widespread diseases of field-grown roses worldwide. Pathogens have been found to interfere with or stimulate plant immune response through the secreted effectors. However, the molecular mechanism involved in inhibition of rose immune response by M. rosae effectors remains poorly understood. In this study, we identified the effector MrSEP43, which played a pivotal role in promoting the virulence of M. rosae and enhancing rose susceptibility by reducing callose deposition, H2O2 accumulation, and the expression of defense genes in jasmonic acid signaling pathway. Through Y2H, BiFC, and LUC assays, MrSEP43 was proved to interact with the rose orphan protein RcBROG. RcBROG, which was a positive regulator of defense against M. rosae, enhanced rose resistance by increasing callose deposition, H2O2 accumulation, and expression of RcERF1 in the ethylene signaling pathway. Overall, our findings suggested that the virulence effector MrSEP43 from M. rosae specifically targeted the orphan protein RcBROG to suppress rose immune response to M. rosae. These results provided new insight into how M. rosae manipulated and successfully colonized rose leaves, and were essential for preventing the breakdown of resistance to rose black spot disease.

Indole-3 acetic acid negatively regulates rose black spot disease resistance through antagonizing the salicylic acid signaling pathway via jasmonic acid.

MAIN CONCLUSION: IAA cooperates with JA to inhibit SA and negatively regulates rose black spot disease resistance. Black spot disease caused by the fungus Marssonina rosae is the most prevalent and severe ailment in rose cultivation, leading to the appearance of black spots on leaves and eventual leaf fall, significantly impacting the utilization of roses in gardens. Salicylic acid (SA) and jasmonic acid (JA) are pivotal hormones that collaborate with indole-3 acetic acid (IAA) in regulating plant defense responses; however, the detailed mechanisms underlying the induction of black spot disease resistance by IAA, JA, and SA remain unclear. In this study, transcript analysis was conducted on resistant (R13-54) and susceptible (R12-26) lines following M. rosae infection. In addition, the impact of exogenous interference with IAA on SA- and JA-mediated disease resistance was examined. The continuous accumulation of JA, in synergy with IAA, inhibited activation of the SA signaling pathway in the early infection stage, thereby negatively regulating the induction of effective resistance to black spot disease. IAA administration alleviated the inhibition of SA on JA to negatively regulate the resistance of susceptible strains by further enhancing the synthesis and accumulation of JA. However, IAA did not contribute to the negative regulation of black spot resistance when high levels of JA were inhibited. Virus-induced gene silencing of RcTIFY10A, an inhibitor of the JA signaling pathway, further suggested that IAA upregulation led to a decrease in disease resistance, a phenomenon not observed when the JA signal was inhibited. Collectively, these findings indicate that the IAA-mediated negative regulation of black spot disease resistance relies on activation of the JA signaling pathway.

Exacerbating effects of circadian rhythm disruption on the systemic lupus erythematosus.

OBJECTIVE: Circadian rhythm disruption (CRD) has been associated with inflammation and immune disorders, but its role in SLE progression is unclear. We aimed to investigate the impact of circadian rhythms on immune function and inflammation and their contribution to SLE progression to lupus nephritis (LN). METHODS: This study retrospectively analysed the clinical characteristics and transcriptional profiles of 373 samples using bioinformatics and machine-learning methods. A flare risk score (FRS) was established to predict overall disease progression for patients with lupus. Mendelian randomisation was used to analyse the causal relationship between CRD and SLE progression. RESULTS: Abnormalities in the circadian pathway were detected in patients with SLE, and lower enrichment levels suggested a disease state (normalised enrichment score=0.6714, p=0.0062). The disruption of circadian rhythms was found to be closely linked to lupus flares, with the FRS showing a strong ability to predict disease progression (area under the curve (AUC) of 5-year prediction: 0.76). The accuracy of disease prediction was improved by using a prognostic nomogram based on FRS (AUC=0.77). Additionally, Mendelian randomisation analysis revealed an inverse causal relationship between CRD and SLE (OR 0.6284 (95% CI 0.3630 to 1.0881), p=0.0485) and a positive causal relationship with glomerular disorders (OR 0.0337 (95% CI 1.634e-3 to 6.934e-1), p=0.0280). CONCLUSION: Our study reveals that genetic characteristics arising from CRD can serve as biomarkers for predicting the exacerbation of SLE. This highlights the crucial impact of CRD on the progression of lupus.

Integrated transcriptomic and lipidomic analysis provides key insights into lipid content changes during pecan (Carya illinoensis) fruit development.

Pecans [Carya illinoinensis (Wangenh.) K. Koch] are highly valued for their abundance of quality healthy lipids, positively impacting human health and making themselves a preferred choice for nutritionally rich foods. However, a comprehensive understanding of the high-resolution characteristics of pecan fruit lipid composition and its dynamic changes, as well as the transfer between embryo and pericarp during development, remains incomplete. In this study, through integrated multi-omics analysis, we observed significant spatiotemporal heterogeneity in lipid changes between the pericarp and embryo. It showed smaller fluctuations and more stable lipid levels in the pericarp while exhibiting a dynamic pattern of initially increasing and then decreasing lipid content in the embryo. In this study, a total of 52 differentially expressed genes were identified, related to fatty acid synthesis and metabolism pathways in the two tissues, with changes in oleic acid and linoleic acid composition being the primary features of the embryo. This research lays the foundation for further understanding the differential regulation mechanisms of lipid metabolism between embryo and pericarp. Overall, this study filled the knowledge gap regarding dynamic changes in pericarp lipid metabolites, provided crucial insights into the lipid metabolism network during pecan fruit development, and established a scientific basis for the genetic improvement of pecan crops.

Integrative Metabolomic and Transcriptomic Analyses Reveal the Mechanism of Petal Blotch Formation in Rosa persica.

Petal blotch is a specific flower color pattern commonly found in angiosperm families. In particular, Rosa persica is characterized by dark red blotches at the base of yellow petals. Modern rose cultivars with blotches inherited the blotch trait from R. persica. Therefore, understanding the mechanism for blotch formation is crucial for breeding rose cultivars with various color patterns. In this study, the metabolites and genes responsible for the blotch formation in R. persica were identified for the first time through metabolomic and transcriptomic analyses using LC-MS/MS and RNA-seq. A total of 157 flavonoids were identified, with 7 anthocyanins as the major flavonoids, namely, cyanidin 3-O-(6″-O-malonyl) glucoside 5-O-glucoside, cyanidin-3-O-glucoside, cyanidin 3-O-galactoside, cyanidin O-rutinoside-O-malonylglucoside, pelargonidin 3-O-glucoside, pelargonidin 3,5-O-diglucoside, and peonidin O-rutinoside-O-malonylglucoside, contributing to pigmentation and color darkening in the blotch parts of R. persica, whereas carotenoids predominantly influenced the color formation of non-blotch parts. Zeaxanthin and antheraxanthin mainly contributed to the yellow color formation of petals at the semi-open and full bloom stages. The expression levels of two 4-coumarate: CoA ligase genes (Rbe014123 and Rbe028518), the dihydroflavonol 4-reductase gene (Rbe013916), the anthocyanidin synthase gene (Rbe016466), and UDP-flavonoid glucosyltransferase gene (Rbe026328) indicated that they might be the key structural genes affecting the formation and color of petal blotch. Correlation analysis combined with weighted gene co-expression network analysis (WGCNA) further characterized 10 transcription factors (TFs). These TFs might participate in the regulation of anthocyanin accumulation in the blotch parts of petals by modulating one or more structural genes. Our results elucidate the compounds and molecular mechanisms underlying petal blotch formation in R. persica and provide valuable candidate genes for the future genetic improvement of rose cultivars with novel flower color patterns.

Combined SNPs sequencing and allele specific proteomics capture reveal functional causality underpinning the 2p25 prostate cancer susceptibility locus.

Genome wide association studies (GWASs) have identified numerous risk loci associated with prostate cancer, yet unraveling their functional significance remains elusive. Leveraging our high-throughput SNPs-seq method, we pinpointed rs4519489 within the multi-ancestry GWAS-discovered 2p25 locus as a potential functional SNP due to its significant allelic differences in protein binding. Here, we conduct a comprehensive analysis of rs4519489 and its associated gene, NOL10, employing diverse cohort data and experimental models. Clinical findings reveal a synergistic effect between rs4519489 genotype and NOL10 expression on prostate cancer prognosis and severity. Through unbiased proteomics screening, we reveal that the risk allele A of rs4519489 exhibits enhanced binding to USF1, a novel oncogenic transcription factor (TF) implicated in prostate cancer progression and prognosis, resulting in elevated NOL10 expression. Furthermore, we elucidate that NOL10 regulates cell cycle pathways, fostering prostate cancer progression. The concurrent expression of NOL10 and USF1 correlates with aggressive prostate cancer characteristics and poorer prognosis. Collectively, our study offers a robust strategy for functional SNP screening and TF identification through high-throughput SNPs-seq and unbiased proteomics, highlighting the rs4519489-USF1-NOL10 regulatory axis as a promising biomarker or therapeutic target for clinical diagnosis and treatment of prostate cancer.

Time-Course Transcriptomic Analysis Reveals Molecular Insights into the Inflorescence and Flower Development of Cardiocrinum giganteum.

Cardiocrinum giganteum is an endemic species of east Asia which is famous for its showy inflorescence and medicinal bulbs. Its inflorescence is a determinate raceme and the flowers bloom synchronously. Morphological observation and time-course transcriptomic analysis were combined to study the process of inflorescence and flower development of C. giganteum. The results show that the autonomic pathway, GA pathway, and the vernalization pathway are involved in the flower formation pathway of C. giganteum. A varied ABCDE flowering model was deduced from the main development process. Moreover, it was found that the flowers in different parts of the raceme in C. giganteum gradually synchronized during development, which is highly important for both evolution and ecology. The results obtained in this work improve our understanding of the process and mechanism of inflorescence and flower development and could be useful for the flowering period regulation and breeding of C. giganteum.

Layered Topological Insulator MnBi2Te4 as a Cathode for a High Rate Performance Aqueous Zinc-Ion Battery.

Recently, the topological insulator MnBi2Te4 has aroused great attention owing to its exotic quantum phenomena and intriguing device applications, but the superior performances of MnBi2Te4 have not been researched in the field of electrochemistry. By theoretical calculations, it is found that MnBi2Te4 exhibits excellent Zn2+ storage and transport properties. Therefore, it is speculated that MnBi2Te4 has excellent electrochemical performance in zinc-ion batteries (ZIBs). In this research, MnBi2Te4 as a pioneer has been explored in ZIBs, showing surprising electrochemical properties. The MnBi2Te4 electrode displays a high average discharge specific capacity (264.8 mA h g-1 at 0.40 A g-1), a competitive cycle life (88.6% of initial capacity after 400 cycles at 4.00 A g-1), and an excellent rate performance (average capacity retention rate of 95.1% from 0.40 to 8.00 A g-1) owing to the fast ion transport of the conductive topological surface state and dissipationless channel of the edge state. Surprisingly, the quasi-solid-state (QSS) MnBi2Te4/Zn battery delivers excellent Zn2+ storage capability and possesses a capacity retention of 79.9% after 1000 cycles at 4.00 A g-1. In addition, the QSS MnBi2Te4/Zn battery can exhibit excellent performance and the GCD curves maintain stability without distortion deformation even at temperatures of 0 and 75 °C.

A 49-bp deletion of PmAP2L results in a double flower phenotype in Prunus mume.

The double flower is an important trait with substantial ornamental value. While mutations in PETALOSA TOE-type or AG (AGAMOUS) genes play a crucial role in enhancing petal number in ornamental plants, the complete mechanism underlying the formation of double flowers remains to be fully elucidated. Through the application of bulked segregant analysis (BSA), we identified a novel gene, APETALA2-like (PmAP2L), characterized by a 49-bp deletion in double-flowered Prunus mume. ß-Glucuronidase (GUS) staining and luciferase reporter assays confirmed that the 49-bp deletion in PmAP2L reduced its binding with Pmu-miRNA172a. Phylogenetic analysis and microsynteny analysis suggested that PmAP2L was not a PETALOSA TOE-type gene, and it might be a new gene controlling the formation of double flower in P. mume. Subsequently, overexpression of PmAP2L-D in tobacco led to a significant rise in the number of stamens and the conversion of stamens to petals. Furthermore, silencing of the homologue of RC5G0530900 in rose significantly reduced the number of petals. Using transient gene expression in P. mume flower buds, we determined the functional differences between PmAP2L-D and PmAP2-S in controlling flower development. Meanwhile, DNA-affinity purification sequencing (DAP-seq), yeast hybrid assays and luciferase reporter assays indicated that PmAP2L negatively regulated the floral organ identity genes by forming a repressor complex with PmTPL and PmHDA6/19. Overall, these findings indicate that the variation in PmAP2L is associated with differences in the regulation of genes responsible for floral organ identity, providing new insights into the double-flower trait and double-flower breeding in plants.

PfPIN5 promotes style elongation by regulating cell length in Primula forbesii Franch.

BACKGROUND AND AIMS: Style dimorphism is one of the polymorphic characteristics of flowers in heterostylous plants, which have two types of flowers: the pin morph, with long styles and shorter anthers, and the thrum morph, with short styles and longer anthers. The formation of dimorphic styles has received attention in the plant world. Previous studies showed that CYP734A50 in Primula determined style length and limited style elongation and that the brassinosteroid metabolic pathway was involved in regulation of style length. However, it is unknown whether there are other factors affecting the style length of Primula. METHODS: Differentially expressed genes highly expressed in pin morph styles were screened based on Primula forbesii transcriptome data. Virus-induced gene silencing was used to silence these genes, and the style length and anatomical changes were observed 20 days after injection. KEY RESULTS: PfPIN5 was highly expressed in pin morph styles. When PfPIN5 was silenced, the style length was shortened in pin and long-homostyle plants by shortening the length of style cells. Moreover, silencing CYP734A50 in thrum morph plants increased the expression level of PfPIN5 significantly, and the style length increased. The results indicated that PfPIN5, an auxin efflux transporter gene, contributed to regulation of style elongation in P. forbesii. CONCLUSIONS: The results implied that the auxin pathway might also be involved in the formation of styles of P. forbesii, providing a new pathway for elucidating the molecular mechanism of style elongation in P. forbesii.

Genome-wide identification of the bHLH transcription factor family in Rosa persica and response to low-temperature stress.

Background: Basic helix-loop-helix (bHLH) transcription factors are involved in plant growth and development, secondary metabolism, and abiotic stress responses have been studied in a variety of plants. Despite their importance in plant biology, the roles and expression patterns of bHLH family genes in Rosa persica have not been determined. Methods: In this study, the RbebHLH family genes were systematically analyzed using bioinformatics methods, and their expression patterns under low-temperature stress were analyzed by transcriptome and related physiological index measurements. Results: In total, 142 RbebHLHs were identified in the genome of R. persica, distributed on seven chromosomes. Phylogenetic analysis including orthologous genes in Arabidopsis divided RbebHLHs into 21 subfamilies, with similar structures and motifs within a subfamily. A collinearity analysis revealed seven tandem duplications and 118 segmental duplications in R. persica and 127, 150, 151, 172, and 164 segmental duplications between R. persica and Arabidopsis thaliana, Prunus mume, Fragaria vesca, Rosa chinensis, and Prunus persica, respectively. A number of cis-regulatory elements associated with abiotic stress response and hormone response were identified in RbebHLHs, and 21 RbebHLHs have potential interactions with the CBF family. In addition, the expression results showed that part of bHLH may regulate the tolerance of R. persica to low-temperature stress through the jasmonic acid and pathway. Transcriptomic data showed that the expression levels of different RbebHLHs varied during overwintering, and the expression of some RbebHLHs was significantly correlated with relative conductivity and MDA content, implying that RbebHLHs play important regulatory roles in R. persica response to low-temperature stress. Overall, this study provides valuable insights into the study of RbebHLHs associated with low-temperature stress.

Nylon Fabric/GO Based Self-Powered Humidity Sensor Based on the Galvanic Cell Principle with High Air Permeability and Rapid-Response.

Flexible humidity sensors have received more and more attention in people's lives, and the problems of gas permeability and power supply issues of the device have long been areas in need of improvement. In this work, inspired by the high air permeability of daily wear clothing and galvanic batteries, a self-powered humidity sensor with high air permeability and fast response is designed. A nylon fabric/GO net (as a humidity sensitive layer and solid electrolyte) is obtained by spraying technique. This structure enables the sensor to have fast response/recovery (0.78 s/0.93 s, calculated at 90% of the final value), ultra-high response (0.83 V) and excellent stability (over 150 cycles) at 35 °C. Such sensors are useful for health monitoring, such as non-contact monitoring of human respiratory rate before and after exercise, and monitoring a level of humidity in the palms, arms, and fingers. This research provides an idea for developing a flexible wearable humidity sensor that is both breathable and self-powered and can also be mass-produced similar to wearable clothing.

Comparative metabolomic analysis reveals nutritional properties and pigmentation mechanism of tea-scented rosehips.

BACKGROUND: The fruits of the genus Rosa, commonly known as rosehips, have attracted significant attention owing to their rich content of various bioactive compounds. However, their utility is generally secondary to the ornamental appeal of their flowers. This study aimed to explore the quality differences among tea-scented rosehips found in Yunnan, China, including those of Rosa odorata var. odorata (RO), Rosa odorata var. gigantea (RG), and Rosa yangii (RY). Morphological characteristics, chemical composition, and antioxidant activity of their fruits were evaluated. RESULTS: The study revealed significant variability in composition and biological activities based on fruit color. RO exhibited the highest levels of polyphenols, flavonoids, anthocyanins, carotenoids, and vitamin C, with the strongest antioxidant activity (10.99 µmol Trolox·g-1 ), followed by RG (7.91 µmol Trolox·g-1 ) and RY (6.52 µmol Trolox·g-1 ). This supports RO's potential as a functional food source. Untargeted metabolomics identified and quantified 502 metabolites, with flavonoids (171) and phenolic acids (147) as the main metabolites. The differential metabolites among the fruits are primarily enriched for flavonoid biosynthesis and phenylpropanoid biosynthesis pathways. Insights into color formation supported the role of anthocyanins, flavones, and flavonols in fruit color variation. CONCLUSION: Tea-scented rosehips offer vibrant colors and high nutritional value with potent biological activities. Rosa odorata var. odorata stands out as a functional food source owing to its rich bioactive compounds. These findings lay the groundwork for utilizing rosehips in functional foods, health supplements, and food additives, emphasizing the practical and beneficial applications of Rosa spp. independent of their ornamental value. © 2023 Society of Chemical Industry.

Genome-Wide Identification of Callose Synthase Family Genes and Their Expression Analysis in Floral Bud Development and Hormonal Responses in Prunus mume.

Callose is an important polysaccharide composed of beta-1,3-glucans and is widely implicated in plant development and defense responses. Callose synthesis is mainly catalyzed by a family of callose synthases, also known as glucan synthase-like (GSL) enzymes. Despite the fact that GSL family genes were studied in a few plant species, their functional roles have not been fully understood in woody perennials. In this study, we identified total of 84 GSL genes in seven plant species and classified them into six phylogenetic clades. An evolutionary analysis revealed different modes of duplication driving the expansion of GSL family genes in monocot and dicot species, with strong purifying selection constraining the protein evolution. We further examined the gene structure, protein sequences, and physiochemical properties of 11 GSL enzymes in Prunus mume and observed strong sequence conservation within the functional domain of PmGSL proteins. However, the exon-intron distribution and protein motif composition are less conservative among PmGSL genes. With a promoter analysis, we detected abundant hormonal responsive cis-acting elements and we inferred the putative transcription factors regulating PmGSLs. To further understand the function of GSL family genes, we analyzed their expression patterns across different tissues, and during the process of floral bud development, pathogen infection, and hormonal responses in Prunus species and identified multiple GSL gene members possibly implicated in the callose deposition associated with bud dormancy cycling, pathogen infection, and hormone signaling. In summary, our study provides a comprehensive understanding of GSL family genes in Prunus species and has laid the foundation for future functional research of callose synthase genes in perennial trees.

Pressure-Regulated Nanoconfined Channels for Highly Effective Mechanical-Electrical Conversion in Proton Battery-Type Self-Powered Pressure Sensor.

Battery-sensing-based all-in-one pressure sensors are generally successfully constructed by mimicking the information transfer of living organisms and the sensing behavior of human skin, possessing features such as low energy consumption and detection of low/high-frequency mechanical signals. To design high-performance all-in-one pressure sensors, a deeper understanding of the intrinsic mechanisms of such sensors is required. Here, a mechanical-electrical conversion mechanism based on pressure-modulated nanoconfined channels is proposed. Then, the mechanism of ion accelerated transport in graphene oxide (GO) nanoconfined channels under pressure is revealed by density functional theory (DFT) calculation. Based on this mechanism, a proton battery-type self-powered pressure sensor MoO3 /GO[CNF/Ca] /activated carbon (AC) is designed with an open-circuit voltage stabilization of 0.648 V, an ultrafast response/recovery time of 86.0 ms/93.0 ms, pressure detection ranges of up to 60.0 kPa, and excellent static/dynamic pressure response. In addition, the one-piece device design enables self-supply, miniaturization, and charge/discharge reuse, showing application potential in wearable electronics, health monitoring, and other fields.

Phylogeny of PmCCD Gene Family and Expression Analysis of Flower Coloration and Stress Response in Prunus mume.

The CCD gene family plays a crucial role in the cleavage of carotenoids, converting them into apocarotenoids. This process not only impacts the physiology and development of plants but also enhances their tolerance toward different stresses. However, the character of the PmCCD gene family and its role in ornamental woody Prunus mume remain unclear. Here, ten non-redundant PmCCD genes were identified from the P. mume genome, and their physicochemical characteristics were predicted. According to the phylogenetic tree, PmCCD proteins were classified into six subfamilies: CCD1, CCD4, CCD7, CCD8, NCED and CCD-like. The same subfamily possessed similar gene structural patterns and numbers of conserved motifs. Ten PmCCD genes were concentrated on three chromosomes. PmCCD genes exhibited interspecific collinearity with P. armeniaca and P. persica. Additionally, PmCCD genes had obvious specificity in different tissues and varieties. Compared with white-flowered 'ZLE', PmCCD1 and PmCCD4 genes were low-expressed in 'HJH' with yellow petals, which suggested PmCCD1 and PmCCD4 might be related to the formation of yellow flowers in P. mume. Nine PmCCD genes could respond to NaCl or PEG treatments. These genes might play a crucial role in salt and drought resistance in P. mume. Moreover, PmVAR3 and PmSAT3/5 interacted with PmCCD4 protein in yeast and tobacco leaf cells. This study laid a foundation for exploring the role of the PmCCD gene family in flower coloration and stress response in P. mume.

Integrative Analysis of Metabolome and Transcriptome Revealed Lutein Metabolism Contributed to Yellow Flower Formation in Prunus mume.

Prunus mume is a famous ornamental woody tree with colorful flowers. P. mume with yellow flowers is one of the most precious varieties. Regretfully, metabolites and regulatory mechanisms of yellow flowers in P. mume are still unclear. This hinders innovation of flower color breeding in P. mume. To elucidate the metabolic components and molecular mechanisms of yellow flowers, we analyzed transcriptome and metabolome between 'HJH' with yellow flowers and 'ZLE' with white flowers. Comparing the metabolome of the two varieties, we determined that carotenoids made contributions to the yellow flowers rather than flavonoids. Lutein was the key differential metabolite to cause yellow coloration of 'HJH'. Transcriptome analysis revealed significant differences in the expression of carotenoid cleavage dioxygenase (CCD) between the two varieties. Specifically, the expression level of PmCCD4 was higher in 'ZLE' than that in 'HJH'. Moreover, we identified six major transcription factors that probably regulated PmCCD4 to affect lutein accumulation. We speculated that carotenoid cleavage genes might be closely related to the yellow flower phenotype in P. mume. Further, the coding sequence of PmCCD4 has been cloned from the 'HJH' petals, and bioinformatics analysis revealed that PmCCD4 possessed conserved histidine residues, ensuring its enzymatic activity. PmCCD4 was closely related to PpCCD4, with a homology of 98.16%. Instantaneous transformation analysis in petal protoplasts of P. mume revealed PmCCD4 localization in the plastid. The overexpression of PmCCD4 significantly reduced the carotenoid content in tobacco plants, especially the lutein content, indicating that lutein might be the primary substrate for PmCCD4. We speculated that PmCCD4 might be involved in the cleavage of lutein in plastids, thereby affecting the formation of yellow flowers in P. mume. This work could establish a material and molecular basis of molecular breeding in P. mume for improving the flower color.

Genome assembly and resequencing analyses provide new insights into the evolution, domestication and ornamental traits of crape myrtle.

Crape myrtle (Lagerstroemia indica) is a globally used ornamental woody plant and is the representative species of Lagerstroemia. However, studies on the evolution and genomic breeding of L. indica have been hindered by the lack of a reference genome. Here we assembled the first high-quality genome of L. indica using PacBio combined with Hi-C scaffolding to anchor the 329.14-Mb genome assembly into 24 pseudochromosomes. We detected a previously undescribed independent whole-genome triplication event occurring 35.5 million years ago in L. indica following its divergence from Punica granatum. After resequencing 73 accessions of Lagerstroemia, the main parents of modern crape myrtle cultivars were found to be L. indica and L. fauriei. During the process of domestication, genetic diversity tended to decrease in many plants, but this was not observed in L. indica. We constructed a high-density genetic linkage map with an average map distance of 0.33 cM. Furthermore, we integrated the results of quantitative trait locus (QTL) using genetic mapping and bulk segregant analysis (BSA), revealing that the major-effect interval controlling internode length (IL) is located on chr1, which contains CDL15, CRG98, and GID1b1 associated with the phytohormone pathways. Analysis of gene expression of the red, purple, and white flower-colour flavonoid pathways revealed that differential expression of multiple genes determined the flower colour of L. indica, with white flowers having the lowest gene expression. In addition, BSA of purple- and green-leaved individuals of populations of L. indica was performed, and the leaf colour loci were mapped to chr12 and chr17. Within these intervals, we identified MYB35, NCED, and KAS1. Our genome assembly provided a foundation for investigating the evolution, population structure, and differentiation of Myrtaceae species and accelerating the molecular breeding of L. indica.