Anthocyanins are the main pigments in ripe strawberry fruits.FaMYB10 and abscisic acid(ABA)are the two major regulators of anthocyanin biosynthesis in the maturation process of strawberry fruits.However,the transcript...Anthocyanins are the main pigments in ripe strawberry fruits.FaMYB10 and abscisic acid(ABA)are the two major regulators of anthocyanin biosynthesis in the maturation process of strawberry fruits.However,the transcriptional regulation of FaMYB10,ABA biosynthesis,and anthocyanin accumulation in strawberry(Fragaria×ananassa)remain largely unknown.Here,a yeast one-hybrid screen using the FaMYB10 promoter identified a class B MADS-domain transcription factor,FaMADS6 in strawberry.FaMADS6 exhibited high expression at the early developmental stage but was hardly detected during maturation of strawberry fruit,a pattern opposite to accumulation of anthocyanins.Transcriptional upregulation of FaMADS6 repressed anthocyanin accumulation and expression of FaMYB10 and the anthocyanin biosynthetic genes,FaCHS,FaCHI,FaF3H,FaANS,and FaUFGT.In contrast,downregulation of FaMADS6 promoted the expression of FaMYB10 and the anthocyanin biosynthetic genes.The promoters of the anthocyanin biosynthetic genes were not directly bound by FaMADS6,in contrast to FaMYB10.Analysis of the DNA binding sequences of FaMADS6 revealed that it also interacted with the promoters of FaNCED2 and FaPYR1,which are involved in the biosynthesis and perception of ABA.Overexpression of FaMADS6 significantly suppressed FaNCED2 and FaPYR1 and ABA synthesis in transgenic strawberry.Together,our findings suggest that FaMADS6 functions as a suppressor of anthocyanin accumulation by directly downregulating FaMYB10 and ABA production during strawberry fruit maturation.展开更多
Cold stress represents a critical constraint on crop productivity,particularly in temperate climates.Despite the established role of abscisic acid(ABA)in cold stress responses,the precise mechanisms through which tran...Cold stress represents a critical constraint on crop productivity,particularly in temperate climates.Despite the established role of abscisic acid(ABA)in cold stress responses,the precise mechanisms through which transcription factors mediate ABAdependent cold tolerance remain elusive.Here,we identify VaMYB4a,a MYB transcription factor from Vitis amurensis Rupr.(Amur grape),as a key regulator of cold tolerance.It integrates ABA signaling with the CBF(C-repeat binding factors)-COR(cold-regulated)pathway to orchestrate cold stress adaptation.Through a combination of overexpression and CRISPR/Cas9-mediated knockout lines in Arabidopsis thaliana,grape callus,and Vitis vinifera L.seedlings,we demonstrate that VaMYB4a enhances freezing tolerance by promoting osmotic regulation,reactive oxygen species(ROS)scavenging,and stomatal closure.VaMYB4a functions as a homo-dimer,with its C-terminal domain being essential for transcriptional activation.Mechanistically,VaMYB4a directly upregulates CBF and COR genes while fine-tuning ABA signaling components such as ABI1 and ABF4.Notably,ABA exhibits a dual role:enhancing VaMYB4a-mediated freezing tolerance under short-term stress but attenuating its effects during prolonged cold exposure,revealing an intricate regulatory crosstalk between cold and hormonal pathways.Our work not only advances the molecular understanding of cold adaptation but also provides a promising genetic target for developing stress-resilient grape varieties to mitigate the impacts of climate change.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFD1600700)Natural Science Foundation of China(Grant Nos.32372644,32472661)+1 种基金Natural Science Foundation of Universities in Anhui Province,China(Grant Nos.2022AH050931,2023AH051043)Anhui Provincial Natural Science Foundation,China(Grant No.2108085MC105).
文摘Anthocyanins are the main pigments in ripe strawberry fruits.FaMYB10 and abscisic acid(ABA)are the two major regulators of anthocyanin biosynthesis in the maturation process of strawberry fruits.However,the transcriptional regulation of FaMYB10,ABA biosynthesis,and anthocyanin accumulation in strawberry(Fragaria×ananassa)remain largely unknown.Here,a yeast one-hybrid screen using the FaMYB10 promoter identified a class B MADS-domain transcription factor,FaMADS6 in strawberry.FaMADS6 exhibited high expression at the early developmental stage but was hardly detected during maturation of strawberry fruit,a pattern opposite to accumulation of anthocyanins.Transcriptional upregulation of FaMADS6 repressed anthocyanin accumulation and expression of FaMYB10 and the anthocyanin biosynthetic genes,FaCHS,FaCHI,FaF3H,FaANS,and FaUFGT.In contrast,downregulation of FaMADS6 promoted the expression of FaMYB10 and the anthocyanin biosynthetic genes.The promoters of the anthocyanin biosynthetic genes were not directly bound by FaMADS6,in contrast to FaMYB10.Analysis of the DNA binding sequences of FaMADS6 revealed that it also interacted with the promoters of FaNCED2 and FaPYR1,which are involved in the biosynthesis and perception of ABA.Overexpression of FaMADS6 significantly suppressed FaNCED2 and FaPYR1 and ABA synthesis in transgenic strawberry.Together,our findings suggest that FaMADS6 functions as a suppressor of anthocyanin accumulation by directly downregulating FaMYB10 and ABA production during strawberry fruit maturation.
基金supported by the Ningxia Hui Autonomous Region Key R&D Program,China(2023BCF01003)the National Natural Science Foundation of China(32472711 and 32060672)the Agricultural Breeding Project of Ningxia Hui Autonomous Region,China(NXNYYZ202101)。
文摘Cold stress represents a critical constraint on crop productivity,particularly in temperate climates.Despite the established role of abscisic acid(ABA)in cold stress responses,the precise mechanisms through which transcription factors mediate ABAdependent cold tolerance remain elusive.Here,we identify VaMYB4a,a MYB transcription factor from Vitis amurensis Rupr.(Amur grape),as a key regulator of cold tolerance.It integrates ABA signaling with the CBF(C-repeat binding factors)-COR(cold-regulated)pathway to orchestrate cold stress adaptation.Through a combination of overexpression and CRISPR/Cas9-mediated knockout lines in Arabidopsis thaliana,grape callus,and Vitis vinifera L.seedlings,we demonstrate that VaMYB4a enhances freezing tolerance by promoting osmotic regulation,reactive oxygen species(ROS)scavenging,and stomatal closure.VaMYB4a functions as a homo-dimer,with its C-terminal domain being essential for transcriptional activation.Mechanistically,VaMYB4a directly upregulates CBF and COR genes while fine-tuning ABA signaling components such as ABI1 and ABF4.Notably,ABA exhibits a dual role:enhancing VaMYB4a-mediated freezing tolerance under short-term stress but attenuating its effects during prolonged cold exposure,revealing an intricate regulatory crosstalk between cold and hormonal pathways.Our work not only advances the molecular understanding of cold adaptation but also provides a promising genetic target for developing stress-resilient grape varieties to mitigate the impacts of climate change.
