DNA methylation mediated by RdDM pathway and demethylation affects furanone accumulation through regulation of QUINONE OXIDOREDUCTASE in strawberry

Recently,increasing evidence suggests that DNA methylation plays a crucial role in fruit ripening.However,the role of DNA methylation in regulating specific traits,such as flavor,remains unclear.Here,we report a role of DNA methylation in affecting furanone biosynthesis in strawberry.Strawberry quinone oxidoreductase(FaQR)is a key enzyme in furanone biosynthesis.There are four FaQR homologs in strawberry cultivar‘Yuexin’,and one of them,FaQR3,contributes∼50%of FaQR transcripts,indicating a major role of FaQR3 in furanone biosynthesis.Through characterization of levels of DNA methylation and FaQR3 transcript and furanone contents during fruit ripening and after the application of DNA methylation inhibitor,we found that the DNA methylation level of the FaQR3 promoter was negatively correlated with FaQR3 expression and furanone accumulation,suggesting that DNA methylation may be involved in furanone biosynthesis through adjusting FaQR3 expression,and responded to different temperatures consistently.In addition,transient expression of a gene in the RNA-directed DNA methylation(RdDM)pathway,FaAGO4,and enrichment analysis of the 24-nucleotide siRNAs suggested that DNA methylation in the FaQR3 promoter is mediated by the RdDM pathway.Transient RNA interference(RNAi)of FaDML indicated that the demethylation pathway may be involved in regulating furanone accumulation.These findings provide new insights into the role of DNA methylation and demethylation in affecting flavor quality in strawberry during fruit ripening.

Visual processing of word and image in the fusiform gyrus

BACKGROUND： The role of the left midfusiform gyrus as a target for visual word processing has been a topic of discussion. Numerous studies have utilized alphabetic writing for subject matter. However, few have addressed visual processing of Chinese characters in the left midfusiform gyrus. OBJECTIVE： To verify visual processing of Chinese characters and images in the left midfusiform gyrus using functional magnetic resonance imaging. DESIGN, TIME AND SETTING： A blocked design paradigm study. Experiments were performed at the Room of Magnetic Resonance, Guangdong Provincial Second People＇s Hospital, China from May to June 2009. PARTICIPANTS： A total of eight undergraduate students were recruited from Guangzhou University of China, comprising two females and six males, aged 20-23 years. The subjects were right-handed which was determined by a Chinese standard questionnaire. None of the subjects had a history of psychoneurosis, familial disease, color blindness, or color weakness. METHODS： A total of eight undergraduates were enrolled as subjects. Picture-naming and verb generation tasks were employed through the use of functional magnetic resonance imaging. Analysis of Functional Neurolmages software was used to process the data. MAIN OUTCOME MEASURES： Visual processing of Chinese characters and images in the left midfusiform gyrus was measured. RESULTS： Picture-naming and verb generation tasks were shown to significantly activate the bilateral midfusiform gyrus. Activation occurred in the visual word form area of the left midfusiform gyrus. CONCLUSION： The left midfusiform gyrus plays a general role in visual processing of Chinese characters and images.

Primary Haemangiopericytoma outside Muscle Cone in Fossa Orbitalis:A Case Report and Review

Purpose:Orbital haemangiopericytoma (HPC) is a rare tumor with great histological variability and unpredictable clinical and biological behavior.The precise cell type origin is uncertain. Method:A case report is provided. Results:A 24-year-old male patient visited an ophthalmologist because of proptosis, strabismus, and movement limitation of the right eye one year ago. These symptoms worsened rapidly. Histopathology,MRI methods and microscopy coil were applied to study the features of HPC.The tumor was removed and the histological examination revealed that it was a primary HPC of the orbit. Conclusion:MRI determined the size,location, circumscription, morphological detail, growth pattern, and relationship between masses and surrounding tissues.The genesis location of this HPC was rare,and its internal morphological characters were different from cases reported in the literature.The new type of microscope showed more details of tumor MR image characters objectively.

DNA methylation controlling abscisic acid catabolism responds to light to mediate strawberry fruit ripening

Phytohormones,epigenetic regulation and environmental factors regulate fruit ripening but their interplay during strawberry fruit ripening remains to be determined.In this study,bagged strawberry fruit exhibited delayed ripening compared with fruit grown in normal light,correlating with reduced abscisic acid(ABA) accumulation.Transcription of the key ABA catabolism gene,ABA 8′-hydroxylase FaCYP707A4,was induced in bagged fruit.With light exclusion whole genome DNA methylation levels were up-regulated,corresponding to a delayed ripening process,while DNA methylation levels in the promoter of FaCYP707A4 were suppressed,correlating with increases in transcript and decreased ABA content.Experiments indicated FaCRY1,a blue light receptor repressed in bagged fruit and FaAGO4,a key protein involved in RNA-directed DNA methylation,could bind to the promoter of FaCYP707A4.The interaction between FaCRY1 and FaAGO4,and an increased enrichment of FaAGO4 directed to the FaCYP707A4 promoter in fruit grown under light suggests FaCRY1 may influence FaAGO4 to modulate the DNA methylation status of the FaCYP707A4 promoter.Furthermore,transient overexpression of FaCRY1,or an increase in FaCRY1 transcription by blue light treatment,increases the methylation level of the FaCYP707A4 promoter,while transient RNA interference of FaCRY1 displayed opposite phenotypes.These findings reveal a mechanism by which DNA methylation influences ABA catabolism,and participates in light-mediated strawberry ripening.

Comparative analysis of fruit firmness and genes associated with cell wall metabolisms in three cultivated strawberries during ripening and postharvest

Cultivated strawberry(Fragaria×ananassa),a world-famous fruit,is subjected to rapid softening during ripening,resulting in a shorter shelf life and severe economic losses during storage and transportation.However,there is limited understanding of the molecular mechanism underlying differences in fruit firmness during ripening and postharvest among cultivated strawberries.Here,we explored this molecular mechanism by comparing three cultivated strawberries via firmness measurement,transcriptome analysis,quantitative real-time polymerase chain reaction,and correlation analysis,and revealed FaEXP7,FaPG2,FaPLA,and Faβ-Gal4 as potential softening activators expressed before harvest to determine fruit with more softened texture and shorter shelf life,and that extremely high expression levels of FaCEL1-1 and FaCEL1-3 during ripening might be accelerators to intensify this situation.Additionally,both the enzyme activities of FaCEL and the expression pattern of FaCEL1-3 showed a significantly negative correlation with fruit firmness after harvest,suggesting that FaCEL1-3 might play a key role in promoting strawberry fruit softening not only during ripening but also postharvest.These results showed that the difference in fruit firmness and shelf life among cultivated strawberries was controlled by the temporal expression pattern of a legion of cell wall-associated genes during ripening and postharvest.

Controllable photodynamic performance via an acidic microenvironment based on two-dimensional metal-organic frameworks for photodynamic therapy

Photodynamic therapy(PDT)is a widely-used technology for cancer therapy,but conventional photosensitizers still face some drawbacks,such as hydrophobicity,inadequate pharmacokinetics,low cell/tissue specificity,and uncontrollable photodynamic performance during the therapeutic process.Herein,we present a controllable photodynamic performance based on two-dimensional metal-organic frameworks(2D Zn-TCPP MOF)that displayed a week PDT effect under a neutral environment upon exposure to a 660 nm laser due to the degeneracy of Q bands of TCPP.However,the 2D Zn-TCPP MOF showed a significantly enhanced PDT effect in an acidic environment under irradiation with a 660 nm laser due to the released TCPP from decomposed MOF structure.From the in vitro outcomes,the 2D Zn-TCPP MOF showed controllable photodynamic performance from neutral to acidic environments.Due to the acidic tumor microenvironment,the 2D Zn-TCPP MOF presented the strongest antitumor effect in vivo under irradiation with a 660 nm laser.This work offers a promising strategy to develop a next-generation photosensitizer.

Study design of deep learning based automatic detection of cerebrovascular diseases on medical imaging: a position paper from Chinese Association of Radiologists

In recent years,with the development of artificial intelligence,especially deep learning technology,researches on automatic detection of cerebrovascular diseases on medical images have made tremendous progress and these models are gradually entering into clinical practice.However,because of the complexity and flexibility of the deep learning algorithms,these researches have great variability on model building,validation process,performance description and results interpretation.The lack of a reliable,consistent,standardized design protocol has,to a certain extent,affected the progress of clinical translation and technology development of computer aided detection systems.After reviewing a large number of literatures and extensive discussion with domestic experts,this position paper put forward recommendations of standardized design on the key steps of deep learning-based automatic image detection models for cerebrovascular diseases.With further research and application expansion,this position paper would continue to be updated and gradually extended to evaluate the generalizability and clinical application efficacy of such tools.