The regulatory mechanism of the MBW(MYB-bHLH-WD40) complex in safflower(Carthamus tinctorius) remains unclear. In the present study,we show that the separate overexpression of the genes CtbHLH41, CtMYB63, and CtWD40-6...The regulatory mechanism of the MBW(MYB-bHLH-WD40) complex in safflower(Carthamus tinctorius) remains unclear. In the present study,we show that the separate overexpression of the genes CtbHLH41, CtMYB63, and CtWD40-6 in Arabidopsis thaliana increased anthocyanin and procyanidin contents in the transgenic plants and partially rescued the trichome reduction phenotype of the corresponding bhlh41, myb63,and wd40-6 single mutants. Overexpression of CtbHLH41, CtMYB63, or CtWD40-6 in safflower significantly increased the content of the natural pigment hydroxysafflor yellow A(HYSA)and negatively regulated safflower petal size.Yeast-two-hybrid, functional, and genetic assays demonstrated that the safflower E3 ligase CtBB1(BIG BROTHER 1) can ubiquitinate CtbHLH41,marking it for degradation through the 26S proteasome and negatively regulating flavonoid accumulation. CtMYB63/CtWD40-6 enhanced the transcriptional activity of CtbHLH41 on the CtDFR(dihydroflavonol 4-reductase) promoter.We propose that the MBW-CtBB1 regulatory module may play an important role in coordinating HYSA accumulation with other response mechanisms.展开更多
Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in ...Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.展开更多
The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H...The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.展开更多
Anthocyanins play diverse roles in plant physiology and stress adaptation.In Arabidopsis,the MYB–bHLH–WD40(MBW)complex has a crucial role in the regulation of anthocyanin synthesis.Here,we report that the R2R3-MYB t...Anthocyanins play diverse roles in plant physiology and stress adaptation.In Arabidopsis,the MYB–bHLH–WD40(MBW)complex has a crucial role in the regulation of anthocyanin synthesis.Here,we report that the R2R3-MYB transcription factor MYB30 and the ubiquitin E3 ligase RHA2b participate in anthocyanin biosynthesis through regulation of the MBW complex.MYB30 was found to negatively regulate sucrose-induced anthocyanin biosynthesis in Arabidopsis seedlings.Expression of multiple genes involved inflavo-noid or anthocyanin biosynthesis was affected in the myb30 mutant,and MYB30 directly repressed the expression of MYB75,which encodes a core component of the MBW complex,by binding to its promoter.Moreover,MYB30 physically interacted with MYB75 to inhibit its activity by repressing MBW complex as-sembly.In addition,sucrose treatment signicantly promoted MYB30 degradation via the action of RHA2b.The ubiquitination and degradation of MYB30 were signicantly attenuated in the rha2b mutant un-der high-sucrose treatment,and further analysis showed that MYB75 directly promoted RHA2b expression in response to high sucrose.Our work thus reveals an anthocyanin biosynthetic regulatory module,RHA2b–MYB30,that controls the function of the MBW complex via MYB75.The repression of MYB75 by MYB30 is released by MYB75-induced RHA2b expression,thus ensuring the self-activation of MYB75 when anthocy-anin synthesis is needed.展开更多
The color of flowers is one of the main characteristics adopted for plants to attract pollinators to ensure the reproductive success of the plant,they are also important in their ornamental appeal in Narcissus plant.I...The color of flowers is one of the main characteristics adopted for plants to attract pollinators to ensure the reproductive success of the plant,they are also important in their ornamental appeal in Narcissus plant.In this study,we identified a NtMYB12 locus encoding an R2R3-MYB transcription factor.Comparative transcriptome analysis of lossand gain-of NtMYB12 tissue relative to wild-type narcissus showed NtMYB12 was mainly involved in flavonol and phenylpropanoid metabolic pathways.Biochemical evidences of dual-luciferase activity and chromatin immunoprecipitation assay supported that MYB12 directly bound to promoters of NtFLS,NtLAR,and NtDFR that were cloned by genome walking assay,and activated NtFLS and NtLAR expression but repressed NtDFR expression.More interestingly,NtMYB12 can interact with NtbHLH1 and NtWD40-1 proteins via R3 domain that were selected by transcriptomebased WGCNA and confirmed by yeast two hybrid,bimolecular fluorescence complementation and coimmunoprecipitation assay.Interaction of NtMYB12 with NtbHLH1 and NtWD40-1 forming MYB-bHLH-WD40 triplex specially activated NtDFR and NtANS expression and promoted(pro)anthocyanin accumulation,while NtMYB12 alone activated NtFLS and NtLAR expression and accumulated flavonols,but repressed NtDFR expression.These results indicated that NtMYB12 alone or NtMYB12-bHLH1-WD40-1 triplex requires for competition of metabolism fluxes between flavonol and(pro)anthocyanin biosynthesis.展开更多
Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytoch...Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.展开更多
基金funded by grants from the Science and Technology Development Project of Jilin Province (No. 20220204058YY)the Science and Technology Research Program of the Education Department of Jilin Province (No. JJKH20210347KJ)+1 种基金the National Natural Science Foundation of China (No. 31771868)Student Innovation and Entrepreneurship Training Program of Jilin Agricultural University。
文摘The regulatory mechanism of the MBW(MYB-bHLH-WD40) complex in safflower(Carthamus tinctorius) remains unclear. In the present study,we show that the separate overexpression of the genes CtbHLH41, CtMYB63, and CtWD40-6 in Arabidopsis thaliana increased anthocyanin and procyanidin contents in the transgenic plants and partially rescued the trichome reduction phenotype of the corresponding bhlh41, myb63,and wd40-6 single mutants. Overexpression of CtbHLH41, CtMYB63, or CtWD40-6 in safflower significantly increased the content of the natural pigment hydroxysafflor yellow A(HYSA)and negatively regulated safflower petal size.Yeast-two-hybrid, functional, and genetic assays demonstrated that the safflower E3 ligase CtBB1(BIG BROTHER 1) can ubiquitinate CtbHLH41,marking it for degradation through the 26S proteasome and negatively regulating flavonoid accumulation. CtMYB63/CtWD40-6 enhanced the transcriptional activity of CtbHLH41 on the CtDFR(dihydroflavonol 4-reductase) promoter.We propose that the MBW-CtBB1 regulatory module may play an important role in coordinating HYSA accumulation with other response mechanisms.
基金supported by the National Natural Science Foundation of China(32201781,32100211)the Department of Science and Technology of Jilin Province(20220508112RC,20210101005JC)+1 种基金the Fundamental Research Fund for the Central Universities(2412023YQ005)China Agriculture Research System(CARS04)。
文摘Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(XDA2004010306)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)Science and Technology Program of Xizang Autonomous Region(XZ202001ZY0003G).
文摘The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.
基金supported by the National Natural Science Foundation of China (grants 32170295 and 31870241 to H.Z.)the China Postdoctoral Science Foundation (grant 2023M730776 to J.H.)the Institutional Research Fund of Sichuan University (grant 2020SCUNL212 to H.L.).
文摘Anthocyanins play diverse roles in plant physiology and stress adaptation.In Arabidopsis,the MYB–bHLH–WD40(MBW)complex has a crucial role in the regulation of anthocyanin synthesis.Here,we report that the R2R3-MYB transcription factor MYB30 and the ubiquitin E3 ligase RHA2b participate in anthocyanin biosynthesis through regulation of the MBW complex.MYB30 was found to negatively regulate sucrose-induced anthocyanin biosynthesis in Arabidopsis seedlings.Expression of multiple genes involved inflavo-noid or anthocyanin biosynthesis was affected in the myb30 mutant,and MYB30 directly repressed the expression of MYB75,which encodes a core component of the MBW complex,by binding to its promoter.Moreover,MYB30 physically interacted with MYB75 to inhibit its activity by repressing MBW complex as-sembly.In addition,sucrose treatment signicantly promoted MYB30 degradation via the action of RHA2b.The ubiquitination and degradation of MYB30 were signicantly attenuated in the rha2b mutant un-der high-sucrose treatment,and further analysis showed that MYB75 directly promoted RHA2b expression in response to high sucrose.Our work thus reveals an anthocyanin biosynthetic regulatory module,RHA2b–MYB30,that controls the function of the MBW complex via MYB75.The repression of MYB75 by MYB30 is released by MYB75-induced RHA2b expression,thus ensuring the self-activation of MYB75 when anthocy-anin synthesis is needed.
基金Open access funding provided by Shanghai Jiao Tong Universitysupported by the“100 talent scientist plan”program of Fujian Province of China to Ying Miao.
文摘The color of flowers is one of the main characteristics adopted for plants to attract pollinators to ensure the reproductive success of the plant,they are also important in their ornamental appeal in Narcissus plant.In this study,we identified a NtMYB12 locus encoding an R2R3-MYB transcription factor.Comparative transcriptome analysis of lossand gain-of NtMYB12 tissue relative to wild-type narcissus showed NtMYB12 was mainly involved in flavonol and phenylpropanoid metabolic pathways.Biochemical evidences of dual-luciferase activity and chromatin immunoprecipitation assay supported that MYB12 directly bound to promoters of NtFLS,NtLAR,and NtDFR that were cloned by genome walking assay,and activated NtFLS and NtLAR expression but repressed NtDFR expression.More interestingly,NtMYB12 can interact with NtbHLH1 and NtWD40-1 proteins via R3 domain that were selected by transcriptomebased WGCNA and confirmed by yeast two hybrid,bimolecular fluorescence complementation and coimmunoprecipitation assay.Interaction of NtMYB12 with NtbHLH1 and NtWD40-1 forming MYB-bHLH-WD40 triplex specially activated NtDFR and NtANS expression and promoted(pro)anthocyanin accumulation,while NtMYB12 alone activated NtFLS and NtLAR expression and accumulated flavonols,but repressed NtDFR expression.These results indicated that NtMYB12 alone or NtMYB12-bHLH1-WD40-1 triplex requires for competition of metabolism fluxes between flavonol and(pro)anthocyanin biosynthesis.
文摘Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.
