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1.
Proc Natl Acad Sci U S A ; 121(20): e2314091121, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38709916

RESUMO

How we reason about objectivity-whether an assertion has a ground truth-has implications for belief formation on wide-ranging topics. For example, if someone perceives climate change to be a matter of subjective opinion similar to the best movie genre, they may consider empirical claims about climate change as mere opinion and irrelevant to their beliefs. Here, we investigate whether the language employed by journalists might influence the perceived objectivity of news claims. Specifically, we ask whether factive verb framing (e.g., "Scientists know climate change is happening") increases perceived objectivity compared to nonfactive framing (e.g., "Scientists believe [...]"). Across eight studies (N = 2,785), participants read news headlines about unique, noncontroversial topics (studies 1a-b, 2a-b) or a familiar, controversial topic (climate change; studies 3a-b, 4a-b) and rated the truth and objectivity of the headlines' claims. Across all eight studies, when claims were presented as beliefs (e.g., "Tortoise breeders believe tortoises are becoming more popular pets"), people consistently judged those claims as more subjective than claims presented as knowledge (e.g., "Tortoise breeders know…"), as well as claims presented as unattributed generics (e.g., "Tortoises are becoming more popular pets"). Surprisingly, verb framing had relatively little, inconsistent influence over participants' judgments of the truth of claims. These results demonstrate how, apart from shaping whether we believe a claim is true or false, epistemic language in media can influence whether we believe a claim has an objective answer at all.


Assuntos
Idioma , Humanos , Feminino , Conhecimento , Masculino , Mudança Climática , Adulto , Percepção , Meios de Comunicação de Massa
2.
Plant Physiol ; 192(2): 1307-1320, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36800200

RESUMO

As the prevalence of diabetes continues to increase, the number of individuals living with diabetes complications will reach an unprecedented magnitude. Continuous use of some synthetic agents to reduce blood glucose levels causes severe side effects, and thus, the demand for nontoxic, affordable drugs persists. Naturally occurring compounds, such as iminosugars derived from the mulberry (Morus spp.), have been shown to reduce blood glucose levels. In mulberry, 1-deoxynojirimycin (DNJ) is the predominant iminosugar. However, the mechanism underlying DNJ biosynthesis is not completely understood. Here, we showed that DNJ in mulberry is derived from sugar and catalyzed through 2-amino-2-deoxy-D-mannitol (ADM) dehydrogenase MnGutB1. Combining both targeted and nontargeted metabolite profiling methods, DNJ and its precursors ADM and nojirimycin (NJ) were quantified in mulberry samples from different tissues. Purified His-tagged MnGutB1 oxidized the hexose derivative ADM to form the 6-oxo compound DNJ. The mutant MnGutB1 D283N lost this remarkable capability. Furthermore, in contrast to virus-induced gene silencing of MnGutB1 in mulberry leaves that disrupted the biosynthesis of DNJ, overexpression of MnGutB1 in hairy roots and light-induced upregulation of MnGutB1 enhanced DNJ accumulation. Our results demonstrated that hexose derivative ADM, rather than lysine derivatives, is the precursor in DNJ biosynthesis, and it is catalyzed by MnGutB1 to form the 6-oxo compound. These results represent a breakthrough in producing DNJ and its analogs for medical use by metabolic engineering or synthetic biology.


Assuntos
1-Desoxinojirimicina , Morus , Humanos , Glicemia , Frutas , Oxirredutases , Folhas de Planta/genética
3.
Sensors (Basel) ; 22(5)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35271171

RESUMO

Vision-based Lane departure warning system (LDWS) has been widely used in modern vehicles to improve drivability and safety. In this paper, a novel LDWS with precise positioning is proposed. Calibration strategy is first presented through a 3D camera imaging model with only three parallel and equally spaced lines, where the three angles of rotation for the transformation from the camera coordinate system to the world coordinate system are deduced. Then camera height is calculated compared to the previous works using a measured one with potential errors. A criterion for lane departure warning with only one of the two lane-markings is proposed to estimate both yaw angle and distance between the lane-markings and the vehicle. Experiments show that calibration strategy can be easily set up and achieve an average of 98.95% accuracy on the lane departure assessment.


Assuntos
Dispositivos Ópticos , Calibragem , Coleta de Dados , Imageamento Tridimensional
4.
Int J Mol Sci ; 23(3)2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35163065

RESUMO

SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes, as unique plant transcription factors, play important roles in plant developmental regulation and stress response adaptation. Although mulberry is a commercially valuable tree species, there have been few systematic studies on SPL genes. In this work, we identified 15 full-length SPL genes in the mulberry genome, which were distributed on 4 Morus notabilis chromosomes. Phylogenetic analysis clustered the SPL genes from five plants (Malus × domestica Borkh, Populus trichocarpa, M. notabilis, Arabidopsis thaliana, and Oryza sativa) into five groups. Two zinc fingers (Zn1 and Zn2) were found in the conserved SBP domain in all of the MnSPLs. Comparative analyses of gene structures and conserved motifs revealed the conservation of MnSPLs within a group, whereas there were significant structure differences among groups. Gene quantitative analysis showed that the expression of MnSPLs had tissue specificity, and MnSPLs had much higher expression levels in older mulberry leaves. Furthermore, transcriptome data showed that the expression levels of MnSPL7 and MnSPL14 were significantly increased under silkworm herbivory. Molecular experiments revealed that MnSPL7 responded to herbivory treatment through promoting the transcription of MnTT2L2 and further upregulating the expression levels of catechin synthesis genes (F3'H, DFR, and LAR).


Assuntos
Bombyx/fisiologia , Catequina/biossíntese , Morus/parasitologia , Fatores de Transcrição/genética , Regulação para Cima , Animais , Mapeamento Cromossômico , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Herbivoria , Morus/genética , Família Multigênica , Especificidade de Órgãos , Filogenia , Proteínas de Plantas/genética
5.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34074049

RESUMO

The vegetative phase transition is a prerequisite for flowering in angiosperm plants. Mulberry miR156 has been confirmed to be a crucial factor in the vegetative phase transition in Arabidopsis thaliana. The over-expression of miR156 in transgenic Populus × canadensis dramatically prolongs the juvenile phase. Here, we find that the expression of mno-miR156 decreases with age in all tissues in mulberry, which led us to study the hierarchical action of miR156 in mulberry. Utilizing degradome sequencing and dual-luciferase reporter assays, nine MnSPLs were shown to be directly regulated by miR156. The results of yeast one-hybrid and dual-luciferase reporter assays also revealed that six MnSPLs could recognize the promoter sequences of mno-miR172 and activate its expression. Our results demonstrate that mno-miR156 performs its role by repressing MnSPL/mno-miR172 pathway expression in mulberry. This work uncovered a miR156/SPLs/miR172 regulation pathway in the development of mulberry and fills a gap in our knowledge about the molecular mechanism of vegetative phase transition in perennial woody plants.


Assuntos
Envelhecimento/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , MicroRNAs/metabolismo , Morus/metabolismo , Proteínas de Plantas/metabolismo , Envelhecimento/genética , Arabidopsis/genética , Biologia Computacional , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica de Plantas/genética , Hydrastis/genética , Hydrastis/metabolismo , MicroRNAs/genética , Morus/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Populus/genética , Populus/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima
6.
J Exp Bot ; 71(20): 6571-6586, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-32720987

RESUMO

The acquisition of new metabolic activities is a major force driving evolution. We explored, from the perspectives of gene family expansion and the evolutionary adaptability of proteins, how new functions have arisen in which terpene synthases diverged. Monoterpenoids are diverse natural compounds that can be divided into cyclic and acyclic skeleton forms according to their chemical structure. We demonstrate, through phylogenetic reconstructions and genome synteny analyses, that the (E)-ß-ocimene synthases, which are acyclic monoterpene synthases (mTPSs), appear to have arisen several times in independent lineages during plant evolution. Bioinformatics analyses and classical mutation experiments identified four sites (I388, F420, S446, and F485) playing important roles in the neofunctionalization of mTPSs. Incubation of neryl diphosphate with Salvia officinalis 1,8-cineole synthase (SCS) and mutated proteins show that these four sites obstruct the isomerization of geranyl diphosphate. Quantum mechanical/molecular mechanical molecular dynamics simulations of models of SCS, SCSY420F/I446S, and SCSN338I/Y420F/I446S/L485F with (3R)-linalyl diphosphate suggest that mutations changed the configuration of the intermediate to obtain new activities. These results provide new perspectives on the evolution of mTPSs, explain the convergent evolution of (E)-ß-ocimene synthases at the molecular level, and identify key residues to control the specificity of engineered mTPSs.


Assuntos
Alquil e Aril Transferases , Magnoliopsida , Monoterpenos Acíclicos , Alcenos , Alquil e Aril Transferases/genética , Magnoliopsida/genética , Monoterpenos , Filogenia
7.
J Integr Plant Biol ; 56(9): 887-901, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24304637

RESUMO

Cytochrome P450s play critical roles in the biosynthesis of physiologically important compounds in plants. These compounds often act as defense toxins to prevent herbivory. In the present study, a total of 174 P450 genes of mulberry (Morus notabilis C.K.Schn) were identified based on bioinformatics analyses. These mulberry P450 genes were divided into nine clans and 47 families and were found to be expressed in a tissue-preferential manner. These genes were compared to the P450 genes in Arabidopsis thaliana. Families CYP80, CYP92, CYP728, CYP733, CYP736, and CYP749 were found to exist in mulberry, and they may play important roles in the biosynthesis of mulberry secondary metabolites. Analyses of the functional and metabolic pathways of these genes indicated that mulberry P450 genes may participate in the metabolism of lipids, other secondary metabolites, xenobiotics, amino acids, cofactors, vitamins, terpenoids, and polyketides. These results provide a foundation for understanding of the structures and biological functions of mulberry P450 genes.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Morus/enzimologia , Morus/genética , Filogenia , Reação em Cadeia da Polimerase
8.
Curr Med Res Opin ; 40(3): 523-535, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38323327

RESUMO

OBJECTIVE: This study aimed to critically assess existing risk prediction models for postoperative mortality in older individuals with hip fractures, with the objective of offering substantive insights for their clinical application. DESIGN: A comprehensive search was conducted across prominent databases, including PubMed, Embase, Cochrane Library, SinoMed, CNKI, VIP, and Wanfang, spanning original articles in both Chinese and English up until 1 December 2023. Two researchers independently extracted pertinent research characteristics, such as predictors, model performance metrics, and modeling methodologies. Additionally, the bias risk and applicability of the incorporated risk prediction models were systematically evaluated using the Prediction Model Risk of Bias Assessment Tool (PROBAST). RESULTS: Within the purview of this investigation, a total of 21 studies were identified, constituting 21 original risk prediction models. The discriminatory capacity of the included risk prediction models, as denoted by the minimum and maximum areas under the subject operating characteristic curve, ranged from 0.710 to 0.964. Noteworthy predictors, recurrent across various models, included age, sex, comorbidities, and nutritional status. However, among the models assessed through the PROBAST framework, only one was deemed to exhibit a low risk of bias. Beyond this assessment, the principal limitations observed in risk prediction models pertain to deficiencies in data analysis, encompassing insufficient sample size and suboptimal handling of missing data. CONCLUSION: Subsequent research endeavors should adopt more stringent experimental designs and employ advanced statistical methodologies in the construction of risk prediction models. Moreover, large-scale external validation studies are warranted to rigorously assess the generalizability and clinical utility of existing models, thereby enhancing their relevance as valuable clinical references.


Assuntos
Fraturas do Quadril , Idoso , Humanos , Comorbidade , Fraturas do Quadril/mortalidade , Fraturas do Quadril/cirurgia , Medição de Risco
9.
Heliyon ; 9(10): e20362, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37818000

RESUMO

Background: Immunosenescence, an age-related deficit in immunity, associated with multiple disorders and making the successful aging a challenge. Although nearly 4000 articles have been published, only few review articles have summarized the research status. In order to better understand the most recent advances, hotspots and development trends in immunosenescence, it is very necessary to conduct a comprehensive bibliometric analysis. Hence, commonly used bibliometric analysis software CiteSpace and VOSviewer were employed to conduct a quantitative analysis and critical evaluation of publications in this study. Methods: Immunosenescence publications were screened from the Web of Science Core Collection (WoSCC). Microsoft Excel 2021, CiteSpace 5.8.R3, and VOSviewer 1.6.17 were used for bibliometric study. Results: A total of 3875 publications were retrieved from WoSCC. After screening by document type (article or review) (352 publications were excluded) and language of English (85 were excluded), 3438 studies were finally used for bibliometric analysis. The literature on immunosenescence had been continuously growing since 1991, and by 2020 it has skyrocketed 312 publications from 240 in 2019. USA (1111 publications, 35.01%) was the leading country of publications, followed by ITALY (379, 11.94%) and ENGLAND (366, 11.53%). Of the authors, Pawelec G from the Tubingen University of GERMANY contributed the greatest articles (93 publications). All the keywords could be divided into five clusters, and additional potent visualization bursts revealed that "gut microbiota," "health," "dysfunction," and "nivolumab" were the active hotspots presently. Conclusion: Based on the current data, we firstly concluded that there will be a dramatically rising publications on immunosenescence, and research teams from USA or GERMANY might be the best chooses for collaboration. Moreover, We particularly emphasized the development potential of mechanism and intervening strateges like "gut microbiota" and "nivolumab" in immunosenescence. We hope to provide new ideas for promoting the basic research and clinical application of immunosenescence.

10.
Patient Educ Couns ; 112: 107709, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37030060

RESUMO

OBJECTIVE: Trust is an essential part of the physician-patient relationship. Yet physicians' perspectives in physician-patient trust has always been ignored, and the concept has not yet been clearly defined and analyzed. This study explores the conceptual understanding of physicians' trust in patients in the context of healthcare and clinical practice and provides a theoretical frameworks foundation for practitioners and researchers. METHODS: Seven databases were systematically searched for relevant studies, including Pubmed, CINAHL, ScienceDirect, Web of Science, CNKI, Wanfang and Weipu. Walker and Avant's approach to concept analysis was performed to extract the concept attributes, antecedents, consequences, and define empirical referents. RESULTS: Of the 8028 articles identified, 43 met the inclusion criteria. Five core attributes were identified: (a) Interaction and support; (b) Confidence and expectation in building trust; (c) Motivation for medical treatment; (d) Socially and medically epistemic competence of patients; (e) Self-reported accuracy. Antecedents were divided into a physician-patient relationship and the social context of medicine. Consequences included treatment outcomes, patient outcomes, and treatment efficiency for physicians and patients. CONCLUSIONS: Our findings offer insights into refining the concept of trust. By collaborating across healthcare trusts, we can contribute to the development of theoretical models and empirical research. This concept analysis serves as a foundation to develop instruments to measure the concept and highlight the need to design a qualitative study and enhancement strategy for physician trust in patients. PRACTICE IMPLICATIONS: Trust in Physicians' perspectives is an essential part of the physician-patient relationship. Establishing and strengthening physicians' trust in patients is significant to healthcare and clinical practice. Concept analysis of physicians' trust in patients will give policymakers a more evident concept and understanding of the importance of the trust improvement strategy and guide healthcare managers to improve theoretical development.


Assuntos
Relações Médico-Paciente , Médicos , Humanos , Pesquisa Qualitativa , Autorrelato
11.
Hortic Res ; 10(7): uhad111, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37786730

RESUMO

Mulberry is a fundamental component of the global sericulture industry, and its positive impact on our health and the environment cannot be overstated. However, the mulberry reference genomes reported previously remained unassembled or unplaced sequences. Here, we report the assembly and analysis of the telomere-to-telomere gap-free reference genome of the mulberry species, Morus notabilis, which has emerged as an important reference in mulberry gene function research and genetic improvement. The mulberry gap-free reference genome produced here provides an unprecedented opportunity for us to study the structure and function of centromeres. Our results revealed that all mulberry centromeric regions share conserved centromeric satellite repeats with different copies. Strikingly, we found that M. notabilis is a species with polycentric chromosomes and the only reported polycentric chromosome species up to now. We propose a compelling model that explains the formation mechanism of new centromeres and addresses the unsolved scientific question of the chromosome fusion-fission cycle in mulberry species. Our study sheds light on the functional genomics, chromosome evolution, and genetic improvement of mulberry species.

12.
ACS Omega ; 8(30): 26871-26881, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37546617

RESUMO

OBJECTIVE: Infections and death have been a part of our daily lives since the COVID-2019 pandemic outbreak in 2019, and the societal and economic consequences have lingered for an unanticipated duration. Novel and effective treatments are still desperately needed around the world to combat the infection. Here, we discovered a novel traditional Chinese medicine formula (TCMF) to potentially combat COVID-19 through reverse systematic pharmacology (disease → targets → TCMF → disease). METHODS: Combining Integrative network pharmacology and the traditional Chinese medicine (TCM) theory, a TCMF for COVID-19 was identified. In silico physiological interactions between herbs and disease hub targets were validated by molecular docking and dynamics simulation. RESULTS: Based on disease-related gene/pathway targets and a combination of reverse pharmacology and TCM meridian tropism theory, a COVID-19-associated herb database was constructed. A new TCMF, including Gancao, Baitouweng, Congbai, and Diyu (GBCD), was discovered for anti-COVID-19 therapy. The KEGG and GO analyses of 49 intersecting genes suggested that GBCD could combat COVID-19 through antiviral, antiinflammation, immunoregulation, and cytoprotection activities. Moreover, these possible effects were validated through docking and MD simulation. CONCLUSIONS: To the best of our knowledge, this study is the first to combine reverse pharmacology and meridian tropism theories for TCMF development, and a novel herbal combination, GBCD, was discovered for anti-COVID-19 therapy.

13.
Front Plant Sci ; 12: 658590, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33889168

RESUMO

Ciboria carunculoides is the dominant causal agent of mulberry sclerotial disease, and it is a necrotrophic fungal pathogen with a narrow host range that causes devastating diseases in mulberry fruit. However, little is known about the interaction between C. carunculoides and mulberry. Here, our transcriptome sequencing results showed that the transcription of genes in the secondary metabolism and defense-related hormone pathways were significantly altered in infected mulberry fruit. Due to the antimicrobial properties of proanthocyanidins (PAs), the activation of PA biosynthetic pathways contributes to defense against pathogens. Salicylic acid (SA) and jasmonic acid (JA) are major plant defense hormones. However, SA signaling and JA signaling are antagonistic to each other. Our results showed that SA signaling was activated, while JA signaling was inhibited, in mulberry fruit infected with C. carunculoides. Yet SA mediated responses are double-edged sword against necrotrophic pathogens, as SA not only activates systemic acquired resistance (SAR) but also suppresses JA signaling. We also show here that the small secreted protein CcSSP1 of C. carunculoides activates SA signaling by targeting pathogenesis-related protein 1 (PR1). These findings reveal that the infection strategy of C. carunculoides functions by regulating SA signaling to inhibit host defense responses.

14.
Clin Transl Gastroenterol ; 12(6): e00370, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34106095

RESUMO

INTRODUCTION: Ischemic colitis (IC) is a common gastrointestinal ischemic disease caused by hypoperfusion or reperfusion injury. However, there are few studies on risk factors associated with poor prognoses of the disease. This study aimed to determine the predictors of poor prognoses in patients with IC and establish a prognostic scoring method with good internal and external validity for identifying severe cases in an early stage. METHODS: We established a prognosis model by conducting a multicenter, retrospective study of patients hospitalized with IC between November 2008 and May 2020. Predictive power was tested using 5-fold internal cross-validation and external validation. RESULTS: The following 6 factors were included in the prognostic model: neutrophil count, D-dimer level, ischemia of the distal ileum, ischemia of the hepatic flexure, ulceration, and luminal stenosis. The area under the receiver-operating characteristic curve for internal cross-validation of the prediction model was 86%, and that for external validation was 95%. During internal validation, our model correctly identified 88.08% of the patients. It was further found that patients younger than 65 years with a higher neutrophil-to-lymphocyte ratio and higher heart rate had poor prognoses. Patients aged 65 years and older with ischemia of terminal ileum, hepatic flexure, splenic flexure, and intestinal stenosis had poor prognoses. DISCUSSION: Patients with ischemia in the hepatic flexure and the distal ileum, endoscopic evidence of ulcer or stenosis, higher neutrophil counts, and higher D-dimer levels have worse prognoses. This information could aid in the selection of timely and appropriate treatment.


Assuntos
Colite Isquêmica/patologia , Índice de Gravidade de Doença , Adulto , Idoso , China , Colite Isquêmica/terapia , Colonoscopia , Progressão da Doença , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
15.
Nanomaterials (Basel) ; 10(11)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233615

RESUMO

Because of its unique eight-membered ring pore structure and the arrangement of cations in its structure, the SSZ-13 molecular sieve has a higher affinity for CO2 than other gases, meaning it has attracted more attention than other porous materials for CO2 adsorption. However, the expensive template and long preparation time limits the industrial production of SSZ-13. In this work, a hollow structure was successfully introduced into the nanosized SSZ-13 molecular sieve with ultrasonic treatment. The effects of the amount of seed added and the ultrasonic time on the structure were investigated. When the amount of seed added was 0.5 wt.% and the ultrasonic time was 60 min, the sample showed a hollow cubic crystal with a diameter of about 50 nm. The specific surface area reached 791.50 m2/g, and the mesoporous ratio was 66.3%. The samples were tested for CO2 adsorption performance at 298 K. It was found that the hollow sample prepared in this work has higher CO2 adsorption capacity compared with the SSZ-13 zeolite prepared with conventional methods. When the adsorption pressure was 0.27 bar, the adsorption amount reached 2.53 mmol/g. The hollow SSZ-13 molecular sieve reached a CO2 adsorption capacity of 4.24 mmol/g at 1 bar.

16.
Plants (Basel) ; 9(2)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32045991

RESUMO

Flavones, one of the largest classes of flavonoids in plants, have a variety of bioactivities and participate in the resistance response of plants to biotic and abiotic stresses. However, flavone synthase (FNS), the key enzyme for flavone biosynthesis, has not yet been characterized in mulberry. In this study, we report that the leaves of certain mulberry cultivars, namely BJ7, PS2, and G14, are rich in flavones. We identified a Fe2+/2-oxoglutarate-dependent dioxygenase from Morus notabilis (MnFNSI) that shows the typical enzymatic activity of a FNSI-type enzyme, and directly converts eriodictyol and naringenin into their corresponding flavones. Overexpression of MnFNSI in tobacco increased the flavones contents in leaves and enhanced the tolerance of tobacco to ultraviolet-B (UV-B) stress. We found that mulberry cultivars with higher flavones contents exhibit less UV-B induced damage after a UV-B treatment. Accordingly, our findings demonstrate that MnFNSI, a FNSI-type enzyme, is involved in the biosynthesis of flavones, which provide protection against UV-B radiation. These results lay the foundation for obtaining mulberry germplasm resources that are more tolerant to UV-B stress and richer in their nutritional value.

17.
Front Plant Sci ; 11: 1142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849701

RESUMO

Terpenoids are considered to be the largest group of secondary metabolites and natural products. Studies have revealed 1-deoxy-D-xylulose 5-phosphate synthase (DXS) is the first and rate-limiting enzyme in the plastidial methylerythritol phosphate pathway, which produces isopentenyl diphosphate and its isoform dimethylallyl diphosphate as terpenoid biosynthesis precursors. Mulberry (Morus L.) is an economically and ecologically important perennial tree with diverse secondary metabolites, including terpenoids that protect plants against bacteria and insects and may be useful for treating human diseases. However, there has been relatively little research regarding DXS genes in mulberry and other woody plant species. In this study, we cloned and functionally characterized three Morus notabilis DXS genes (MnDXS1, MnDXS2A, and MnDXS2B). Bioinformatics analyses indicated MnDXS1 belongs to clade 1, whereas MnDXS2A and MnDXS2B are in clade 2. The three encoded MnDXS proteins are localized to chloroplasts. Additionally, substantial differences in MnDXS expression patterns were observed in diverse tissues and in response to insect feeding and methyl jasmonate treatment. Moreover, overexpression of MnDXS1 in Arabidopsis thaliana increased the gibberellic acid content and resulted in early flowering, whereas overexpression of MnDXS2A enhanced root growth and increased the chlorophyll and carotenoid content. Our findings indicate that MnDXS functions vary among the clades, which may be useful for further elucidation of the functions of the DXS genes in mulberry.

18.
Front Microbiol ; 11: 603927, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33519746

RESUMO

Scleromitrula shiraiana is a necrotrophic fungus with a narrow host range, and is one of the main causal pathogens of mulberry sclerotial disease. However, its molecular mechanisms and pathogenesis are unclear. Here, we report a 39.0 Mb high-quality genome sequence for S. shiraiana strain SX-001. The S. shiraiana genome contains 11,327 protein-coding genes. The number of genes and genome size of S. shiraiana are similar to most other Ascomycetes. The cross-similarities and differences of S. shiraiana with the closely related Sclerotinia sclerotiorum and Botrytis cinerea indicated that S. shiraiana differentiated earlier from their common ancestor. A comparative genomic analysis showed that S. shiraiana has fewer genes encoding cell wall-degrading enzymes (CWDEs) and effector proteins than that of S. sclerotiorum and B. cinerea, as well as many other Ascomycetes. This is probably a key factor in the weaker aggressiveness of S. shiraiana to other plants. S. shiraiana has many species-specific genes encoding secondary metabolism core enzymes. The diversity of secondary metabolites may be related to the adaptation of these pathogens to specific ecological niches. However, melanin and oxalic acid are conserved metabolites among many Sclerotiniaceae fungi, and may be essential for survival and infection. Our results provide insights into the narrow host range of S. shiraiana and its adaptation to mulberries.

19.
Hortic Res ; 7(1): 83, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528695

RESUMO

Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste, bright color, and high nutritional value. However, neither the regulatory mechanism controlling flavonoid biosynthesis in mulberry nor the molecular basis of different mulberry fruit colors is fully understood. Here, we report that a flavonoid homeostasis network comprising activation and feedback regulation mechanisms determines mulberry fruit color. In vitro and in vivo assays showed that MYBA-bHLH3-TTG1 regulates the biosynthesis of anthocyanins, while TT2L1 and TT2L2 work with bHLH3 or GL3 and form a MYB-bHLH-WD40 (MBW) complex with TTG1 to regulate proanthocyanidin (PA) synthesis. Functional and expression analyses showed that bHLH3 is a key regulator of the regulatory network controlling mulberry fruit coloration and that MYB4 is activated by MBW complexes and participates in negative feedback control of the regulatory network to balance the accumulation of anthocyanins and proanthocyanidins. Our research demonstrates that the interaction between bHLH3 and MYB4 in the homeostasis regulatory network ensures that the fruits accumulate desirable flavonoids and that this network is stable in pigment-rich mulberry fruits. However, the abnormal expression of bHLH3 disrupts the balance of the network and redirects flavonoid metabolic flux in pale-colored fruits, resulting in differences in the levels and proportions of anthocyanins, flavones, and flavonols among differently colored mulberry fruits (red, yellow, and white). The results of our study reveal the molecular basis of the diversity of mulberry fruit colors.

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