As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a pro...As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a protein that plays a critical role in determining malate accumulation and vacuolar acidification by directly regulating the transcription of aluminum-activated malate transporter 9(MdALMT9),vacuolar ATPase subunit A(MdVHA-A),and vacuolar pyrophosphatase 1(MdVHP1)in apple.In addition,the bHLH TF MdCIbHLH1 interacts with MdMYB73 and enhances the transcriptional activity of MdMYB73.Our previous studies demonstrated that the BTB-BACK-TAZ domain protein MdBT2 can degrade MdCIbHLH1 to influence malate accumulation and vacuolar acidification.However,the potential upstream regulators of MdMYB73 are currently unknown.In this study,we found that MdBT2 directly interacts with and degrades MdMYB73 through the ubiquitin/26S proteasome pathway to regulate malate accumulation and vacuolar acidification.A series of functional assays with apple calli and fruit showed that MdBT2 controls malate accumulation and vacuolar acidification in an MdMYB73-dependent manner.Overall,our findings shed light on the mechanism by which the BTB-BACK-TAZ domain protein MdBT2 regulates malate accumulation and vacuolar acidification by targeting MdMYB73 and MdCIbHLH1 for ubiquitination in apple.This information may help guide traditional breeding programs and fruit tree molecular breeding,and lead to improvements in fruit quality and stress tolerance.展开更多
Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica...Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica)has multiple functions,modulating both anthocyanin biosynthesis and cell acidification.Here,we show that MdbHLH3 also regulates ethylene biosynthesis and leaf senescence by promoting the expression of dehydratase-enolasephosphatase complex 1(MdDEP1).Therefore,we propose a model whereby MdbHLH3 acts as a crucial factor that modulates anthocyanin biosynthesis and cell acidification in addition to fruit ripening and leaf senescence by regulating distinct target genes.展开更多
Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development ...Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development in plants;however,the underlying mechanism is largely unknown,including chrysanthemum.Here,it was found that the overexpression of CmANR1,a chrysanthemum MADS-box TF gene,promoted both adventitious root(AR)and lateral root(LR)development in chrysanthemum.Whole transcriptome sequencing analysis revealed a series of differentially expressed unigenes(DEGs)in the roots of CmANR1-transgenic chrysanthemum plants compared to wild-type plants.Functional annotation of these DEGs by alignment with Gene Ontology(GO)terms and biochemical pathway Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis indicated that CmANR1 TF exhibited“DNA binding”and“catalytic”activity,as well as participated in“phytohormone signal transduction”.Both chromatin immunoprecipitation–polymerase chain reaction(ChIP-PCR)and gel electrophoresis mobility shift assays(EMSA)indicated the direct binding of CmPIN2 to the recognition site CArG-box motif by CmANR1.Finally,a firefly luciferase imaging assay demonstrated the transcriptional activation of CmPIN2 by CmANR1 in vivo.Overall,our results provide novel insights into the mechanisms of MADS-box TF CmANR1 modulation of both AR and LR development,which occurs by directly regulating auxin transport gene CmPIN2 in chrysanthemum.展开更多
Sugars are involved in plant growth,fruit quality,and signaling perception.Therefore,understanding the mechanisms involved in soluble sugar accumulation is essential to understand fruit development.Here,we report that...Sugars are involved in plant growth,fruit quality,and signaling perception.Therefore,understanding the mechanisms involved in soluble sugar accumulation is essential to understand fruit development.Here,we report that Md PFPβ,a pyrophosphatedependent phosphofructokinase gene,regulates soluble sugar accumulation by enhancing the photosynthetic performance and sugar-metabolizing enzyme activities in apple(Malus domestica Borkh.).Biochemical analysis revealed that a basic helix-loop-helix(b HLH)transcription factor,Mdb HLH3,binds to the Md PFPβpromoter and activates its expression,thus promoting soluble sugar accumulation in apple fruit.In addition,Md PFPβoverexpression in tomato influenced photosynthesis and carbon metabolism in the plant.Furthermore,we determined that Mdb HLH3 increases photosynthetic rates and soluble sugar accumulation in apple by activating Md PFPβexpression.Our results thus shed light on the mechanism of soluble sugar accumulation in apple leaves and fruit:Mdb HLH3 regulates soluble sugar accumulation by activating Md PFPβgene expression and coordinating carbohydrate allocation.展开更多
基金supported by grants from the National Key Research and Development Program of China(2018YFD1000200)the National Natural Science Foundation of China(31972375)+1 种基金Ministry of Agriculture(CARS-27)Shandong Province(SDAIT-06-03).
文摘As an important primary metabolite,malate plays a key role in regulating osmotic pressure,pH homeostasis,stress tolerance,and fruit quality of apple.The R2R3-MYB transcription factor(TF)MdMYB73 was identified as a protein that plays a critical role in determining malate accumulation and vacuolar acidification by directly regulating the transcription of aluminum-activated malate transporter 9(MdALMT9),vacuolar ATPase subunit A(MdVHA-A),and vacuolar pyrophosphatase 1(MdVHP1)in apple.In addition,the bHLH TF MdCIbHLH1 interacts with MdMYB73 and enhances the transcriptional activity of MdMYB73.Our previous studies demonstrated that the BTB-BACK-TAZ domain protein MdBT2 can degrade MdCIbHLH1 to influence malate accumulation and vacuolar acidification.However,the potential upstream regulators of MdMYB73 are currently unknown.In this study,we found that MdBT2 directly interacts with and degrades MdMYB73 through the ubiquitin/26S proteasome pathway to regulate malate accumulation and vacuolar acidification.A series of functional assays with apple calli and fruit showed that MdBT2 controls malate accumulation and vacuolar acidification in an MdMYB73-dependent manner.Overall,our findings shed light on the mechanism by which the BTB-BACK-TAZ domain protein MdBT2 regulates malate accumulation and vacuolar acidification by targeting MdMYB73 and MdCIbHLH1 for ubiquitination in apple.This information may help guide traditional breeding programs and fruit tree molecular breeding,and lead to improvements in fruit quality and stress tolerance.
基金supported by grants from the National Key Research and Development Program of China(2018YFD1000200)the National Natural Science Foundation of China(31972375)+2 种基金the Ministry of Agriculture of China(CARS-28)Shandong Province(SDAIT-06-03)Nanjing Agricultural University(ZW201805).
文摘Basic helix−loop−helix(bHLH)domain-containing transcription factors are known for their roles in regulating various plant growth and developmental processes.Previously,we showed that MdbHLH3 from apple(Malus domestica)has multiple functions,modulating both anthocyanin biosynthesis and cell acidification.Here,we show that MdbHLH3 also regulates ethylene biosynthesis and leaf senescence by promoting the expression of dehydratase-enolasephosphatase complex 1(MdDEP1).Therefore,we propose a model whereby MdbHLH3 acts as a crucial factor that modulates anthocyanin biosynthesis and cell acidification in addition to fruit ripening and leaf senescence by regulating distinct target genes.
基金This work was supported by grants from the National Natural Science Foundation of China(31601728)Shandong Province(ZR2016CQ13)Young Scientists Funds of Shandong Agricultural University(564024,24024).
文摘Plant root systems are essential for many physiological processes,including water and nutrient absorption.MADS-box transcription factor(TF)genes have been characterized as the important regulators of root development in plants;however,the underlying mechanism is largely unknown,including chrysanthemum.Here,it was found that the overexpression of CmANR1,a chrysanthemum MADS-box TF gene,promoted both adventitious root(AR)and lateral root(LR)development in chrysanthemum.Whole transcriptome sequencing analysis revealed a series of differentially expressed unigenes(DEGs)in the roots of CmANR1-transgenic chrysanthemum plants compared to wild-type plants.Functional annotation of these DEGs by alignment with Gene Ontology(GO)terms and biochemical pathway Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis indicated that CmANR1 TF exhibited“DNA binding”and“catalytic”activity,as well as participated in“phytohormone signal transduction”.Both chromatin immunoprecipitation–polymerase chain reaction(ChIP-PCR)and gel electrophoresis mobility shift assays(EMSA)indicated the direct binding of CmPIN2 to the recognition site CArG-box motif by CmANR1.Finally,a firefly luciferase imaging assay demonstrated the transcriptional activation of CmPIN2 by CmANR1 in vivo.Overall,our results provide novel insights into the mechanisms of MADS-box TF CmANR1 modulation of both AR and LR development,which occurs by directly regulating auxin transport gene CmPIN2 in chrysanthemum.
基金supported by grants from the National Natural Science Foundation of China(32122080,31972375,31902049)National Key Research and Development Program of China(2018YFD1000200)Shandong Province(ZR2020YQ25)。
文摘Sugars are involved in plant growth,fruit quality,and signaling perception.Therefore,understanding the mechanisms involved in soluble sugar accumulation is essential to understand fruit development.Here,we report that Md PFPβ,a pyrophosphatedependent phosphofructokinase gene,regulates soluble sugar accumulation by enhancing the photosynthetic performance and sugar-metabolizing enzyme activities in apple(Malus domestica Borkh.).Biochemical analysis revealed that a basic helix-loop-helix(b HLH)transcription factor,Mdb HLH3,binds to the Md PFPβpromoter and activates its expression,thus promoting soluble sugar accumulation in apple fruit.In addition,Md PFPβoverexpression in tomato influenced photosynthesis and carbon metabolism in the plant.Furthermore,we determined that Mdb HLH3 increases photosynthetic rates and soluble sugar accumulation in apple by activating Md PFPβexpression.Our results thus shed light on the mechanism of soluble sugar accumulation in apple leaves and fruit:Mdb HLH3 regulates soluble sugar accumulation by activating Md PFPβgene expression and coordinating carbohydrate allocation.
