Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport deriv...Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport derived from the green pear‘Zaosu’.A new genetic map was constructed from a population derived from the cross of‘Yuluxiang’and‘Hongzaosu’,from which PpBBX24 was identified as a crucial gene controlling anthocyanin accumulation.Genetic and phylogenetic evidences revealed that PpBBX24 is a repressor of anthocyanin biosynthesis in pear.A 14 bp deletion was detected in the third exon of PpBBX24 in‘Hongzaosu’,resulting in premature termination of protein translation.The truncated PpBBX24 protein was a positive regulator of anthocyanin biosynthesis by activating the transcription of PpCHS and PpUFGT.Three independent variations in the BBX24 coding region that led to premature termination of translation were detected in other pear bud sports and the progeny of a bud sport that all accumulate anthocyanins.The genome of‘Hongzaosu’was assembled using both long-read and short-read sequences.By combining genomic and transcriptomic data,allele-specific expression of PpMYB110a was observed in the fruit skin of‘Hongzaosu',which was likely caused by a large variation in the promoter.This work enhances understanding of coloration in red pears and provides a novel genomic resource for further studies on‘Hongzaosu’pear.展开更多
PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TP...PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TPL1 co-repressor complex represses the expression of PpMYB114,but not PpMYB10,via histone deacetylation.However,the precise molecular mechanism underlying the ethylene-mediated inhibition of PpMYB10 expression remains to be elucidated.The results of this study reveal a high correlation between the expression patterns of PpMYB114 and PpMYB10 in response to ethylene signaling.Moreover,PpMYB114 was found to promote the expression of PpMYB10 by directly binding to the MYB-binding site(MBS)element within its promoter region.Transient overexpression or silencing of PpMYB114 resulted in the promotion or inhibition of PpMYB10 expression in mature pear fruit,respectively.The overexpression of PpMYB114 in pear calli significantly induced PpMYB10 expression and anthocyanin biosynthesis.Conversely,transient silencing of PpMYB10 in PpMYB114-OE pear calli hindered the promotive effect of PpMYB114 on anthocyanin biosynthesis,indicating that PpMYB114 induces anthocyanin biosynthesis,which is at least partially dependent on the transcriptional activation of PpMYB10.Collectively,these results indicate that ethylene may inhibit the expression of PpMYB10 by repressing PpMYB114.Our findings provide insights into a possible mechanism involving ethylene-inhibited PpMYB10 in pear and reveal the regulatory relationship between the R2R3-MYBs involved in anthocyanin biosynthesis.展开更多
Bud endodormancy is a complex physiological process that is indispensable for the survival,growth,and development of deciduous perennial plants.The timely release of endodormancy is essential for flowering and fruit p...Bud endodormancy is a complex physiological process that is indispensable for the survival,growth,and development of deciduous perennial plants.The timely release of endodormancy is essential for flowering and fruit production of deciduous fruit trees.A better understanding of the mechanism of endodormancy will be of great help in the artificial regulation of endodormancy to cope with climate change and in creating new cultivars with different chilling requirements.Studies in poplar have clarified the mechanism of vegetative bud endodormancy,but the endodormancy of floral buds in fruit trees needs further study.In this review,we focus on the molecular regulation of endodormancy induction,maintenance and release in floral buds of deciduous fruit trees.We also describe recent advances in quantitative trait loci analysis of chilling requirements in fruit trees.We discuss phytohormones,epigenetic regulation,and the detailed molecular network controlling endodormancy,centered on SHORT VEGETATIVE PHASE(SVP)and Dormancy-associated MADS-box(DAM)genes during endodormancy maintenance and release.Combining previous studies and our observations,we propose a regulatory model for bud endodormancy and offer some perspectives for the future.展开更多
Dormancy-associated MADS-box(DAM)genes serve as crucial regulators of the endodormancy cycle in rosaceous plants.Although pear DAM genes have been identified previously,the lack of a high-quality reference genome and ...Dormancy-associated MADS-box(DAM)genes serve as crucial regulators of the endodormancy cycle in rosaceous plants.Although pear DAM genes have been identified previously,the lack of a high-quality reference genome and techniques to study gene function have prevented accurate genome-wide analysis and functional verification of such genes.Additionally,the contribution of other genes to the regulation of endodormancy release remains poorly understood.In this study,a high-quality genome assembly for'Cuiguan'pear(Pyrus pyrifolia),which is a leading cultivar with a low chilling requirement cultivated in China,was constructed using PacBio and Hi-C technologies.Using this genome sequence,we revealed that pear DAM genes were tandemly clustered on Chr8 and Chr15 and were differentially expressed in the buds between'Cuiguan'and the high-chilling-requirement cultivar'Suli'during the dormancy cycle.Using a virus-induced gene silencing system,we determined the repressive effects of DAM genes on bud break.Several novel genes potentially involved in the regulation of endodormancy release were identified by RNA sequencing and H3K4me3 chromatin immunoprecipitation sequencing analyses of‘Suli'buds during artificial chilling using the new reference genome.Our findings enrich the knowledge of the regulatory mechanism underlying endodormancy release and chilling requirements and provide a foundation for the practical regulation of dormancy release in fruit trees as an adaptation to climate change.展开更多
Microglia-mediated neuroinflammation is widely perceived as a contributor to numerous neurological diseases and mental disorders including depression.Discs large homolog 1(Dlg1),an adaptor protein,regulates cell polar...Microglia-mediated neuroinflammation is widely perceived as a contributor to numerous neurological diseases and mental disorders including depression.Discs large homolog 1(Dlg1),an adaptor protein,regulates cell polarization and the function of K?channels,which are reported to regulate the activation of microglia.However,little is known about the role of Dlg1 in microglia and the maintenance of central nervous system homeostasis.In this study,we found that Dlg1 knockdown suppressed lipopolysaccharide(LPS)-induced inflammation by downregulating the activation of nuclear factor-jB signaling and the mitogen-activated protein kinase pathway in microglia.Moreover,using an inducible Dlg1 microglia-specific knockout(Dlg1flox/flox;CX3CR1CreER)mouse line,we found that microglial Dlg1 knockout reduced the activation of microglia and alleviated the LPS-induced depressionlike behavior.In summary,our results demonstrated that Dlg1 plays a critical role in microglial activation and thus provides a potential therapeutic target for the clinical treatment of depression.展开更多
CF3I is a potential SF6 alternative gas.In order to study the insulation properties and synergistic effects of CF3I/N2 and CF3I/CO2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionizat...CF3I is a potential SF6 alternative gas.In order to study the insulation properties and synergistic effects of CF3I/N2 and CF3I/CO2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionization coefficient α,attachment coefficient η and the critical equivalent electrical field strength（E/N）（cr）.The results show that the（E/N）（cr）of CF3I gas at 300 K is 1.2 times that of SF6 gas,and CF3I/N2 and CF3I/CO2 gas mixtures both have synergistic effect occurred.The synergistic effect coefficient of CF3I/CO2 gas mixture was higher than that of CF3I/N2 gas mixture.But the（E/N）（cr）of CF3I/N2 is higher than that of CF3I/CO2 under the same conditions.When the content of CF3I exceeds 20%,the （E/N）（cr） of CF3I/N2 and CF3I/CO2 gas mixture increase linearly with the increasing of CF3I gas content.The breakdown voltage of CF3I/N2 gas mixture is also higher than that of CF3I/CO2 gas mixture in slightly non-uniform electrical field under power frequency voltage,but the synergistic effect coefficients of the two gas mixtures are basically the same.展开更多
For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism resp...For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LR22C150001 to SB,LY22C150003 to JN)the Specialized Research Fund for Major Science and Technique of Zhejiang Province of China(2021C02066-5)+1 种基金the National Natural Science Foundation of China(32072545 to YT,32272639 to SB)the China Agriculture Research System of MOF and MARA(CARS-28)and the Yunnan Science and Technology Talent and Platform Program(202205AF150041)。
文摘Genetic variation contributes to the phenotypic diversity of plants.Most red pear cultivars that accumulate anthocyanins originated from somatic variation and are termed as bud sports.‘Hongzaosu’is a bud sport derived from the green pear‘Zaosu’.A new genetic map was constructed from a population derived from the cross of‘Yuluxiang’and‘Hongzaosu’,from which PpBBX24 was identified as a crucial gene controlling anthocyanin accumulation.Genetic and phylogenetic evidences revealed that PpBBX24 is a repressor of anthocyanin biosynthesis in pear.A 14 bp deletion was detected in the third exon of PpBBX24 in‘Hongzaosu’,resulting in premature termination of protein translation.The truncated PpBBX24 protein was a positive regulator of anthocyanin biosynthesis by activating the transcription of PpCHS and PpUFGT.Three independent variations in the BBX24 coding region that led to premature termination of translation were detected in other pear bud sports and the progeny of a bud sport that all accumulate anthocyanins.The genome of‘Hongzaosu’was assembled using both long-read and short-read sequences.By combining genomic and transcriptomic data,allele-specific expression of PpMYB110a was observed in the fruit skin of‘Hongzaosu',which was likely caused by a large variation in the promoter.This work enhances understanding of coloration in red pears and provides a novel genomic resource for further studies on‘Hongzaosu’pear.
基金supported by the National Natural Science Foundation of China(32072545 and 32272678)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)the Zhejiang Provincial Natural Science Foundation of China(LY22C150003)。
文摘PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TPL1 co-repressor complex represses the expression of PpMYB114,but not PpMYB10,via histone deacetylation.However,the precise molecular mechanism underlying the ethylene-mediated inhibition of PpMYB10 expression remains to be elucidated.The results of this study reveal a high correlation between the expression patterns of PpMYB114 and PpMYB10 in response to ethylene signaling.Moreover,PpMYB114 was found to promote the expression of PpMYB10 by directly binding to the MYB-binding site(MBS)element within its promoter region.Transient overexpression or silencing of PpMYB114 resulted in the promotion or inhibition of PpMYB10 expression in mature pear fruit,respectively.The overexpression of PpMYB114 in pear calli significantly induced PpMYB10 expression and anthocyanin biosynthesis.Conversely,transient silencing of PpMYB10 in PpMYB114-OE pear calli hindered the promotive effect of PpMYB114 on anthocyanin biosynthesis,indicating that PpMYB114 induces anthocyanin biosynthesis,which is at least partially dependent on the transcriptional activation of PpMYB10.Collectively,these results indicate that ethylene may inhibit the expression of PpMYB10 by repressing PpMYB114.Our findings provide insights into a possible mechanism involving ethylene-inhibited PpMYB10 in pear and reveal the regulatory relationship between the R2R3-MYBs involved in anthocyanin biosynthesis.
基金the National Key Research and Development Program of China(2018YFD1000104)the China Agriculture Research System of MOF and MARA.
文摘Bud endodormancy is a complex physiological process that is indispensable for the survival,growth,and development of deciduous perennial plants.The timely release of endodormancy is essential for flowering and fruit production of deciduous fruit trees.A better understanding of the mechanism of endodormancy will be of great help in the artificial regulation of endodormancy to cope with climate change and in creating new cultivars with different chilling requirements.Studies in poplar have clarified the mechanism of vegetative bud endodormancy,but the endodormancy of floral buds in fruit trees needs further study.In this review,we focus on the molecular regulation of endodormancy induction,maintenance and release in floral buds of deciduous fruit trees.We also describe recent advances in quantitative trait loci analysis of chilling requirements in fruit trees.We discuss phytohormones,epigenetic regulation,and the detailed molecular network controlling endodormancy,centered on SHORT VEGETATIVE PHASE(SVP)and Dormancy-associated MADS-box(DAM)genes during endodormancy maintenance and release.Combining previous studies and our observations,we propose a regulatory model for bud endodormancy and offer some perspectives for the future.
基金This work was supported by the National Key Research and Developmental Program of China(2018YFD1000104)the Earmarked Fund for China Agriculture Research System(CARS-28)the Specialized Research Fund for Major Science and Technique of Zhejiang Province of China(2016C02052-4 and 2018C02011).
文摘Dormancy-associated MADS-box(DAM)genes serve as crucial regulators of the endodormancy cycle in rosaceous plants.Although pear DAM genes have been identified previously,the lack of a high-quality reference genome and techniques to study gene function have prevented accurate genome-wide analysis and functional verification of such genes.Additionally,the contribution of other genes to the regulation of endodormancy release remains poorly understood.In this study,a high-quality genome assembly for'Cuiguan'pear(Pyrus pyrifolia),which is a leading cultivar with a low chilling requirement cultivated in China,was constructed using PacBio and Hi-C technologies.Using this genome sequence,we revealed that pear DAM genes were tandemly clustered on Chr8 and Chr15 and were differentially expressed in the buds between'Cuiguan'and the high-chilling-requirement cultivar'Suli'during the dormancy cycle.Using a virus-induced gene silencing system,we determined the repressive effects of DAM genes on bud break.Several novel genes potentially involved in the regulation of endodormancy release were identified by RNA sequencing and H3K4me3 chromatin immunoprecipitation sequencing analyses of‘Suli'buds during artificial chilling using the new reference genome.Our findings enrich the knowledge of the regulatory mechanism underlying endodormancy release and chilling requirements and provide a foundation for the practical regulation of dormancy release in fruit trees as an adaptation to climate change.
基金the National Natural Science Foundation of China(82071218,81630026,and 81930029).
文摘Microglia-mediated neuroinflammation is widely perceived as a contributor to numerous neurological diseases and mental disorders including depression.Discs large homolog 1(Dlg1),an adaptor protein,regulates cell polarization and the function of K?channels,which are reported to regulate the activation of microglia.However,little is known about the role of Dlg1 in microglia and the maintenance of central nervous system homeostasis.In this study,we found that Dlg1 knockdown suppressed lipopolysaccharide(LPS)-induced inflammation by downregulating the activation of nuclear factor-jB signaling and the mitogen-activated protein kinase pathway in microglia.Moreover,using an inducible Dlg1 microglia-specific knockout(Dlg1flox/flox;CX3CR1CreER)mouse line,we found that microglial Dlg1 knockout reduced the activation of microglia and alleviated the LPS-induced depressionlike behavior.In summary,our results demonstrated that Dlg1 plays a critical role in microglial activation and thus provides a potential therapeutic target for the clinical treatment of depression.
基金supported by National Natural Science Foundation of China (Grant No.51337006)China Postdoctoral Science Foundation (2016M602728)the Science and Technology Project of SGCC ‘Research on SF_6 Alternative Gas for Insulation and Arc Quenching Application’
文摘CF3I is a potential SF6 alternative gas.In order to study the insulation properties and synergistic effects of CF3I/N2 and CF3I/CO2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionization coefficient α,attachment coefficient η and the critical equivalent electrical field strength（E/N）（cr）.The results show that the（E/N）（cr）of CF3I gas at 300 K is 1.2 times that of SF6 gas,and CF3I/N2 and CF3I/CO2 gas mixtures both have synergistic effect occurred.The synergistic effect coefficient of CF3I/CO2 gas mixture was higher than that of CF3I/N2 gas mixture.But the（E/N）（cr）of CF3I/N2 is higher than that of CF3I/CO2 under the same conditions.When the content of CF3I exceeds 20%,the （E/N）（cr） of CF3I/N2 and CF3I/CO2 gas mixture increase linearly with the increasing of CF3I gas content.The breakdown voltage of CF3I/N2 gas mixture is also higher than that of CF3I/CO2 gas mixture in slightly non-uniform electrical field under power frequency voltage,but the synergistic effect coefficients of the two gas mixtures are basically the same.
基金supported by the National Natural Science Foundation of China(Grant Nos.32072545,32272639 and 32260745)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LTGN23C150009 and LY22C150003)Zhejiang University Experimental Technology Research Project(Grant No.SYBJS202217).
文摘For red pear,the anthocyanin content is a crucial factor determining the fruit skin color,which affects consumer preferences.Low overnight temperatures promote anthocyanin accumulation,but the molecular mechanism responsible is unclear.In this study,‘Hongzaosu’pear(Pyrus pyrifolia×Pyrus communis)fruit were treated with a low nighttime temperature(LNT,16℃)or a warm nighttime temperature(WNT,26℃),with sampling conducted within two diurnal cycles.The results showed that LNT promoted anthocyanin accumulation in the fruit skin.The structural anthocyanin biosynthetic genes PpCHS,PpF3H,and PpUFGT exhibited a rhythmic increase in expression at night under LNT.To examine the underlying mechanism,RNA sequencing was conducted using pear calli exposed to LNT and WNT for different durations(24,48,72,or 96 h).Transcriptome analysis revealed 285 differentially expressed genes(DEGs)common to all pairwise comparisons of LNT-and WNT-treated calli of‘Clapp's Favorite’(P.communis)at the sampling time points.KEGG pathway and gene ontology enrichment analyses indicated that the common DEGs were enriched in secondary metabolic processes and phenylpropanoid metabolic processes,which are associated with anthocyanin biosynthesis.The transcription factor PpCDF5,which was responsive to LNT,was selected for further study.Dual-luciferase assays showed that PpCDF5 activated the transcription of anthocyanin biosynthetic genes PpMYB10,PpCHS,PpF3H,PpDFR,PpANS,and PpUFGT.The yeast one-hybrid and EMSA assays demonstrated that PpCDF5 directly binds to the PpF3H promoter,which contains an AAAG motif.Overexpression of PpCDF5 in pear calli and transient overexpression in pear fruit both increased anthocyanin accumulation.The results indicate that PpCDF5 is involved in LNT-induced anthocyanin biosynthesis in pear fruit and provide insights into the molecular regulation of commercial fruit coloration.
