The regulation of apple(Malus domestica)fruit texture during ripening is complex and a fundamental determinant of its commercial quality.In climacteric fruit,ripening-related processes are regulated by ethylene(ET),an...The regulation of apple(Malus domestica)fruit texture during ripening is complex and a fundamental determinant of its commercial quality.In climacteric fruit,ripening-related processes are regulated by ethylene(ET),and jasmonate(JA)is also involved in the ethylene biosynthesis pathway,mainly through the transcription factor MYC2.However,the molecular genetic mechanism for fruit ripening processes between the JA and ET signaling pathways still needs to be elucidated.In order to explore how JA regulates apple fruit ripening through ERF4,we used’Gala’and’Ralls Janet’fruit at different developmental stages as experimental materials to determine the fruit firmness and related gene expression analysis.Meanwhile,we carried out different hormone treatments on’Gala’fruit at ripening stage.Here,we show that ERF4 is a core JA signaling hub protein JASMONATE ZIM-DOMAIN(JAZ)interactor that affects ethylene signaling pathways.During fruit development,ERF4 represses the expression of ACS1 and ACO1 by interacting with JAZ,as well as with the JA-activated transcription factor MYC2.Ripening is promoted in JAZ-suppressed apples.Thus,ERF4 acts as a molecular link between ethylene and JA hormone signals,and the natural variation of the ERF4Ethylene-responsive binding factor-associated amphiphilic repression(EAR)motif decreases repression of ethylene biosynthesis genes.展开更多
Endoreduplication is prevalent during plant growth and development,and is often correlated with large cell and organ size.Despite its prevalence,the transcriptional regulatory mechanisms underlying the transition from...Endoreduplication is prevalent during plant growth and development,and is often correlated with large cell and organ size.Despite its prevalence,the transcriptional regulatory mechanisms underlying the transition from mitotic cell division to endoreduplication remain elusive.Here,we characterize ETHYLENE-RESPONSIVEELEMENTBINDING FACTOR 4(ERF4)as a positive regulator of endoreduplication through its function as a transcriptional repressor.ERF4 was specifically expressed in mature tissues in which the cells were undergoing expansion,but was rarely expressed in young organs.Plants overexpressing ERF4 exhibited much larger cells and organs,while plants that lacked functional ERF4 displayed smaller organs than the wild-type.ERF4 was further shown to regulate cell size by controlling the endopolyploidy level in the nuclei.Moreover,ERF4 physically associates with the class I TEOSINTE BRANCHED 1/CYCLOIDEA/PCF(TCP)protein TCP15,a transcription factor that inhibits endoreduplication by activating the expression of a key cell-cycle gene,CYCLIN A2;3(CYCA2;3).A molecular and genetic analysis revealed that ERF4promotes endoreduplication by directly suppressing the expression of CYCA2;3.Together,this study demonstrates that ERF4 and TCP15 function as a module to antagonistically regulate each other?s activity in regulating downstream genes,thereby controlling the switch from the mitotic cell cycle to endoreduplication during leaf development.These findings expand our understanding of how the control of the cell cycle is fine-tuned by an ERF4–TCP15 transcriptional complex.展开更多
Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 th...Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.展开更多
AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （...AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （ABA） and ethylene stimulus ATSYR1 gene encodes a syntaxin localizing at the plasma membrane in Arabidopsis, which can be induced by abiotic stress. To identify mutation lines for gene functional analysis, real-time PCR was employed to detect the expression level of AtERF4 and ATSYR1 in homozygous T-DNA insertion mutant line, respectively. Real-time PCR is a powerful tool which can be used to detect steady-state mRNA levels specifically, sensitively and reproducibly. Comparing to other forms of quantitative RT-PCR, the amount of amplified products can be detected by real-time PCR instantly and thus is a preferable alternative. In this study, RNA with T-DNA inserting into exon could be detected in AtERF4 knock-out mutation line. The results indicated that AtERF4 had been trucked in transcription level. On the other hand, T-DNA inserting into the promoter of gene ATSYR1 had no effect on reducing the expression level ofATSYR1 gene. Further molecular and phenotype studies now are ongoing to clarify the potential consequences of AtERF4 and ATSYR1 deficiency in Arabidopsis展开更多
基金supported by the National Key Research and Development Program [Grant No.2018YFD1000200]the National Natural Science Foundation of China [Grant Nos.31872941,32072543]+2 种基金the Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects [Grant No.CEFFPXM2019_014207_000032]the 111 Project [Grant No.B17043]the Engineering Research Center of Breeding and Propagation of Horticultural Crops,Ministry of Education。
文摘The regulation of apple(Malus domestica)fruit texture during ripening is complex and a fundamental determinant of its commercial quality.In climacteric fruit,ripening-related processes are regulated by ethylene(ET),and jasmonate(JA)is also involved in the ethylene biosynthesis pathway,mainly through the transcription factor MYC2.However,the molecular genetic mechanism for fruit ripening processes between the JA and ET signaling pathways still needs to be elucidated.In order to explore how JA regulates apple fruit ripening through ERF4,we used’Gala’and’Ralls Janet’fruit at different developmental stages as experimental materials to determine the fruit firmness and related gene expression analysis.Meanwhile,we carried out different hormone treatments on’Gala’fruit at ripening stage.Here,we show that ERF4 is a core JA signaling hub protein JASMONATE ZIM-DOMAIN(JAZ)interactor that affects ethylene signaling pathways.During fruit development,ERF4 represses the expression of ACS1 and ACO1 by interacting with JAZ,as well as with the JA-activated transcription factor MYC2.Ripening is promoted in JAZ-suppressed apples.Thus,ERF4 acts as a molecular link between ethylene and JA hormone signals,and the natural variation of the ERF4Ethylene-responsive binding factor-associated amphiphilic repression(EAR)motif decreases repression of ethylene biosynthesis genes.
基金supported by the National Natural Science Foundation of China(31600237)the Agricultural Science and Technology Innovation Program(ASTIP-TRIC02)+1 种基金the Key Science and Technology Projects of Sichuan Tobacco Institute(SCYC202002)the Central Public-Interest Scientific Institution Basal Research Fund(16102320200002)。
文摘Endoreduplication is prevalent during plant growth and development,and is often correlated with large cell and organ size.Despite its prevalence,the transcriptional regulatory mechanisms underlying the transition from mitotic cell division to endoreduplication remain elusive.Here,we characterize ETHYLENE-RESPONSIVEELEMENTBINDING FACTOR 4(ERF4)as a positive regulator of endoreduplication through its function as a transcriptional repressor.ERF4 was specifically expressed in mature tissues in which the cells were undergoing expansion,but was rarely expressed in young organs.Plants overexpressing ERF4 exhibited much larger cells and organs,while plants that lacked functional ERF4 displayed smaller organs than the wild-type.ERF4 was further shown to regulate cell size by controlling the endopolyploidy level in the nuclei.Moreover,ERF4 physically associates with the class I TEOSINTE BRANCHED 1/CYCLOIDEA/PCF(TCP)protein TCP15,a transcription factor that inhibits endoreduplication by activating the expression of a key cell-cycle gene,CYCLIN A2;3(CYCA2;3).A molecular and genetic analysis revealed that ERF4promotes endoreduplication by directly suppressing the expression of CYCA2;3.Together,this study demonstrates that ERF4 and TCP15 function as a module to antagonistically regulate each other?s activity in regulating downstream genes,thereby controlling the switch from the mitotic cell cycle to endoreduplication during leaf development.These findings expand our understanding of how the control of the cell cycle is fine-tuned by an ERF4–TCP15 transcriptional complex.
基金supported by the National Natural Science Foundation of China(grant nos.32000250 and 32170364)the China Postdoctoral Science Foundation(grant no.2020M682997)+2 种基金the Key Area Research and Development Program of Guangdong Province(grant no.2021B0707010006)the Science,Technology and Innovation Commission of Shenzhen Municipality(grant nos.KCXFZ-20201221173203009 and KCXFZ20211020164207012)the Dapeng New District Science and Technology Program(grant nos.KJYF202101-09 and RCTD20180102)。
文摘Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.
基金Supported by National High Technology Program (2008ZX08004-002, 2009ZX08009-032B)Key Research Plan of Heilongjiang Province (GA06B103)Education Department Plan of Heilongjiang Province(11521021, 1152024)
文摘AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （ABA） and ethylene stimulus ATSYR1 gene encodes a syntaxin localizing at the plasma membrane in Arabidopsis, which can be induced by abiotic stress. To identify mutation lines for gene functional analysis, real-time PCR was employed to detect the expression level of AtERF4 and ATSYR1 in homozygous T-DNA insertion mutant line, respectively. Real-time PCR is a powerful tool which can be used to detect steady-state mRNA levels specifically, sensitively and reproducibly. Comparing to other forms of quantitative RT-PCR, the amount of amplified products can be detected by real-time PCR instantly and thus is a preferable alternative. In this study, RNA with T-DNA inserting into exon could be detected in AtERF4 knock-out mutation line. The results indicated that AtERF4 had been trucked in transcription level. On the other hand, T-DNA inserting into the promoter of gene ATSYR1 had no effect on reducing the expression level ofATSYR1 gene. Further molecular and phenotype studies now are ongoing to clarify the potential consequences of AtERF4 and ATSYR1 deficiency in Arabidopsis
