Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains...Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.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
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
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
基金supported by the Department of Science and Technology of Jilin Province(20220508112RC).
文摘Anthocyanin biosynthesis in plants is spatiotemporally controlled by a suite of transcription factors,with MYB proteins playing a key regulatory role.However,the evolution of the distinct roles of MYB paralogs remains poorly understood.Our previous studies have established GmMYBA2 and GmMYBA3 as the regulators of seed coat and floral anthocyanin production in soybean(Glycine max),respectively.In this study,we reveal the functional divergence of their paralog GmMYBA1 in orchestrating light-responsive anthocyanin biosynthesis in juvenile tissues and stems.In brief,hypocotyl/stem-and young leaf-predominant expression of GmMYBA1 correlates with photoprotective anthocyanin accumulation.Ectopic overexpression of GmMYBA1 induces systemic pigmentation across leaves,stems,and reproductive organs,whereas RNAi-mediated silencing of GmMYBA1 significantly reduces anthocyanin accumulation in the hypocotyl.Light-dark shift assays confirmed that GmMYBA1 is required for hypocotyl pigmentation,while dual-luciferase assays revealed the specific regulation of the GmMYBA paralogs by GmSTF1/2(soybean TGACG-motif binding factor 1/2).GmSTF1/2 both activate GmMYBA1,with only GmSTF2 weakly inducing GmMYBA2 and neither affecting GmMYBA3.Further investigation indicated that the differential transactivation of GmMYBA promoters largely resulted from their cis-element difference,suggesting regulatory divergence as a driver of MYB paralog diversification.Our findings position GmMYBA1 as the central MYB activator integrating light signaling with anthocyanin biosynthesis,with paralog specialization reflecting evolutionary subfunctionalization post-gene duplication.
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.
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.
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.
