Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effect...Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density.However,the regulatory mechanism of rapeseed plant architecture is poorly understood.In this study,a dwarf rapeseed mutant dwarf08(df08)is obtained by ethyl methane sulfonate(EMS)-mutagenesis.The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and controlled by a single semi-dominant gene.The hybrid plants(F1)show a semi-dwarf phenotype.Through map-based cloning and transgenic assay,we confirm that the nonsynonymous single nucleotide variant(SNV)(C to T)in BnaC03.BIN2,which is homologous with Arabidopsis(Arabidopsis thaliana)BIN2,is responsible for the dwarfism of df08.BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassinosteroids(BRs)signal transduction.Proline to Leucine substitution in 284(P284L)enhances the protein stability of BnaC03.bin2-D,disrupts BRs signal transduction and affects the expression of genes regulating cell division,leading to dwarfism of df08.This study provides a new insight for the mechanism of rapeseed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.展开更多
The blue-light receptor cryptochrome 1(CRY1)primarily mediates blue-light inhibition of hypocotyl elongation in Arabidopsis.However,the underlying mechanisms remain largely elusive.We report here that CRY1 inhibits hy...The blue-light receptor cryptochrome 1(CRY1)primarily mediates blue-light inhibition of hypocotyl elongation in Arabidopsis.However,the underlying mechanisms remain largely elusive.We report here that CRY1 inhibits hypocotyl elongation by repressing brassinosteroid(BR)signaling.A genetic interaction assay reveals the negative regulatory effect of CRY1 on the function of BZR1,a core transcription factor in the BR signaling pathway.We demonstrated that CRY1 interacts with the DNA-binding domain of BZR1 to interfere with the DNA-binding ability of BZR1,and represses its transcriptional activity.Furthermore,we found that CRY1 promotes the phosphorylation of BZR1 and inhibits the nuclear accumulation of BZR1.Interestingly,we discovered that CRY1 interacts with the GSK3-like kinase BIN2 and enhances the interaction of BIN2 and BZR1 in a light-dependent manner.Our findings revealed that CRY1 negatively regulates the function of BZR1 through at least two mechanisms:interfering with the DNA-binding ability of BZR1 and promoting the phosphorylation of BZR1.Therefore,we uncover a novel CRY1-BIN2-BZR1 regulatory module that mediates crosstalk between blue light and BR signaling to coordinate plant growth in Arabidopsis.展开更多
Salicylic acid (SA) plays an important role in plant immune response, including resistance to pathogens and systemic acquired resistance. Two major components, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPRs) and TGA...Salicylic acid (SA) plays an important role in plant immune response, including resistance to pathogens and systemic acquired resistance. Two major components, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPRs) and TGACG motif-binding transcription factors (TGAs), are known to mediate SA signaling, which might also be orchestrated by other hormonal and environmental changes. Nevertheless, the molecular and functional interactions between SA signaling components and other cellular signaling pathways remain poorly understood. Here we showed that the steroid plant hormone brassinosteroid (BR) promotes SA responses by inactivating BR-INSENSITIVE 2 (BIN2), which inhibits the redox-sensitive clade I TGAs in Arabidopsis. We found that both BR and the BIN2 inhibitor bikinin synergistically increase SA-mediated physiological responses, such as resistance to Pst DC3000. Our genetic and biochemical analyses indicated that BIN2 functionally interacts with TGA1 and TGA4, but not with other TGAs. We further demonstrated that BIN2 phosphorylates Ser-202 of TGA4, resulting in the suppression of the redox-dependent interaction between TGA4 and NPR1 as well as destabilization of TGA4. Consistently, transgenic Arabidopsis overexpressing TGA4-YFP with a S202A mutation displayed enhanced SA responses compared to the wild-type TGA4-YFP plants. Taken together, these results suggest a novel crosstalk mechanism by which BR signaling coordinates the SA responses mediated by redox-sensitive clade I TGAs.展开更多
High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlyi...High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlying mechanisms remain obscure.Here,we demonstrate that the glycogen synthase kinase 3(GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2(BIN2),a negative component in the BR signaling pathway,interacts with the master heat-responsive transcription factors CLASS A1 HEAT SHOCK TRANSCRIPTION FACTORS(HsfA1s).Furthermore,BIN2 phosphorylates HsfA1d on T263 and S56 to suppress its nuclear localization and inhibit its DNA-binding ability,respectively.BR signaling promotes plant thermotolerance by releasing the BIN2 suppression of HsfA1d to facilitate its nuclear localization and DNA binding.Our study provides insights into the molecular mechanisms by which BRs promote plant thermotolerance by strongly regulating HsfA1d through BIN2 and suggests potential ways to improve crop yield under extreme high temperatures.展开更多
It is well known that plantgrowth,development,and response to environmental stresses are harmonized through theaction of a suite of growth and defense signaling molecules.Brassinosteroid(BR)is a steroid hormone that r...It is well known that plantgrowth,development,and response to environmental stresses are harmonized through theaction of a suite of growth and defense signaling molecules.Brassinosteroid(BR)is a steroid hormone that regulates plant growth and development.展开更多
Stomata are epidermal pores that are essential for water evaporation and gas exchange in plants.Stomatal development is orchestrated by intrinsic developmental programs,hormonal controls,and environmental cues.The ste...Stomata are epidermal pores that are essential for water evaporation and gas exchange in plants.Stomatal development is orchestrated by intrinsic developmental programs,hormonal controls,and environmental cues.The steroid hormone brassinosteroid(BR)inhibits stomatal lineage progression by regulating BIN2 and BSL proteins in leaves.Notably,BR is known to promote stomatal development in hypocotyls as opposed to leaves;however,its molecular mechanism remains elusive.Here,we show that BR signaling has a dual regulatory role in controlling stomatal development in Arabidopsis hypocotyls.We found that brassinolide(BL;the most active BR)regulates stomatal development differently in a concentration-dependent manner.At low and moderate concentrations,BL promoted stomatal formation by upregulating the expression of SPEECHLESS(SPCH)and its target genes independently of BIN2 regulation.In contrast,high concentrations of BL and bikinin,which is a specific inhibitor of BIN2 and its homologs,significantly reduced stomatal formation.Genetic analyses revealed that BIN2 regulates stomatal development in hypocotyls through molecular mechanisms distinct from the regulatory mechanism of the cotyledons.In hypocotyls,BIN2 promoted stomatal development by inactivating BZR1,which suppresses the expression of SPCH and its target genes.Taken together,our results suggest that BR precisely coordinates the stomatal development of hypocotyls using an antagonistic control of SPCH expression via BZR1-dependent and BZR1-independent transcriptional regulation.展开更多
Cold stress is a major environmental factor that adversely affects plant growth and development. The C-repeat binding factor/DRE binding factor 1 （CBF/DREB1） transcriptional regulatory cascade has been shown to play...Cold stress is a major environmental factor that adversely affects plant growth and development. The C-repeat binding factor/DRE binding factor 1 （CBF/DREB1） transcriptional regulatory cascade has been shown to play important roles in plant response to cold. Here we demonstrate that two key components of brassinosteroid （BR） signaling modulate freezing tolerance of Arabidopsis plants. The loss-of-function mutant of the GSK3-1ike kinases involved in BR signaling, bin2-3 bill bil2, showed increased freezing tolerance, whereas overexpression of BIN2 resulted in hypersensitivity to freezing stress under both non-acclimated and acclimated conditions. By contrast, gain-of-function mutants of the transcription factors BZR1 and BES1 displayed enhanced freezing tolerance, and consistently cold treatment could induce the accumulation of dephosphorylated BZR1. Biochemical and genetic analyses showed that BZR1 acts upstream of CBF1 and CBF2 to directly regulate their expression. Moreover, we found that BZR1 also regulated other COR genes uncoupled with CBFs, such as WKRY6, PYL6, SOCl, JMT, and SAG21, to modulate plant response to cold stress. Consistently, wrky6 mutants showed decreased freezing tolerance. Taken together, our results indicate that BZR1 positively modulates plant freezing tolerance through CBF-dependent and CBF-independent pathways.展开更多
Brassinosteroids(BRs)and abscisic acid(ABA)are essential regulators of plant growth and stress tolerance.Although the antagonistic interaction of BRs and ABA is proposed to ensure the balance between growth and defens...Brassinosteroids(BRs)and abscisic acid(ABA)are essential regulators of plant growth and stress tolerance.Although the antagonistic interaction of BRs and ABA is proposed to ensure the balance between growth and defense in model plants,the crosstalk between BRs and ABA in response to chilling in tomato(Solanum lycopersicum),a warmclimate horticultural crop,is unclear.Here,we determined that overexpression of the BR biosynthesis gene DWARF(DWF)or the key BR signaling gene BRASSINAZOLE-RESISTANT1(BZR1)increases ABA levels in response to chilling stress via positively regulating the expression of the ABA biosynthesis gene 9-CIS-EPOXYCAROTENOID DIOXYGENASE1(NCED1).BR-induced chilling tolerance was mostly dependent on ABA biosynthesis.Chilling stress or high BR levels decreased the abundance of BRASSINOSTEROID-INSENSITIVE2(BIN2),a negative regulator of BR signaling.Moreover,we observed that chilling stress increases BR levels and results in the accumulation of BZR1.BIN2negatively regulated both the accumulation of BZR1protein and chilling tolerance by suppressing ABA biosynthesis.Our results demonstrate that BR signaling positively regulates chilling tolerance via ABA biosynthesis in tomato.The study has implications in production of warm-climate crops in horticulture.展开更多
The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by mult...The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by multiple intrinsic developmental signals and environmental factors.KiN1o,the catalytic subunit of the su-crose non-fermenting 1-related protein kinase 1(SnRK1)complex,has been shown to preferentially localize in the nucleus ofmeristemoids,where it phosphorylates and stabilizes the SPEECHLESS transcrip-tion factor,thereby promoting stomatal development.However,the regulatory mechanism governing the nuclear localization of KiN1o in meristemoids remains unclear.Here,we demonstrate that brassinosteroid(BR)inhibits KIN10's nuclear localization by modulating KINβ2 through BR-INSENSITIVE2(BIN2)-mediated phosphorylation.In meristemoids,KIN1o is predominantly nuclear,while KINp2 is mainly cytosolic.Inter-fering with the nuclear localization of KIN10 or enhancing the membrane association of KiNp2 impairs sto-matal development and leads to excessive epidermal cell proliferation.Cell biology and biochemical ana-lyses reveal that BR signaling could inhibit KIN10 nuclear localization by enhancing KIN2 membrane association,while BIN2 interacts with and phosphorylates KINp2 to reduce its membrane association and its interaction with KiN1o.Taken together,these findings suggest that the precise regulation of the subcellular localization of the SnRK1 complex,at least in part by BR signaling,is critical for meristemoid differentiation and stomatal development.展开更多
基金supported by the National Key Research and Development Program of China(2022YFD1200401)the National Natural Science Foundation of China(U22A20477,32172095)the Central Public-interest Scientific Institution Basal Research Fund(Y2022QC21).
文摘Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density.However,the regulatory mechanism of rapeseed plant architecture is poorly understood.In this study,a dwarf rapeseed mutant dwarf08(df08)is obtained by ethyl methane sulfonate(EMS)-mutagenesis.The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and controlled by a single semi-dominant gene.The hybrid plants(F1)show a semi-dwarf phenotype.Through map-based cloning and transgenic assay,we confirm that the nonsynonymous single nucleotide variant(SNV)(C to T)in BnaC03.BIN2,which is homologous with Arabidopsis(Arabidopsis thaliana)BIN2,is responsible for the dwarfism of df08.BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassinosteroids(BRs)signal transduction.Proline to Leucine substitution in 284(P284L)enhances the protein stability of BnaC03.bin2-D,disrupts BRs signal transduction and affects the expression of genes regulating cell division,leading to dwarfism of df08.This study provides a new insight for the mechanism of rapeseed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.
文摘The blue-light receptor cryptochrome 1(CRY1)primarily mediates blue-light inhibition of hypocotyl elongation in Arabidopsis.However,the underlying mechanisms remain largely elusive.We report here that CRY1 inhibits hypocotyl elongation by repressing brassinosteroid(BR)signaling.A genetic interaction assay reveals the negative regulatory effect of CRY1 on the function of BZR1,a core transcription factor in the BR signaling pathway.We demonstrated that CRY1 interacts with the DNA-binding domain of BZR1 to interfere with the DNA-binding ability of BZR1,and represses its transcriptional activity.Furthermore,we found that CRY1 promotes the phosphorylation of BZR1 and inhibits the nuclear accumulation of BZR1.Interestingly,we discovered that CRY1 interacts with the GSK3-like kinase BIN2 and enhances the interaction of BIN2 and BZR1 in a light-dependent manner.Our findings revealed that CRY1 negatively regulates the function of BZR1 through at least two mechanisms:interfering with the DNA-binding ability of BZR1 and promoting the phosphorylation of BZR1.Therefore,we uncover a novel CRY1-BIN2-BZR1 regulatory module that mediates crosstalk between blue light and BR signaling to coordinate plant growth in Arabidopsis.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(Ministry of Science and ICT,orMinistryof Education)(2021R1A2C1006617 and 2020R1A6A1A06046728 to T.W.K.2021R1A2C1007516toS-K.K).
文摘Salicylic acid (SA) plays an important role in plant immune response, including resistance to pathogens and systemic acquired resistance. Two major components, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPRs) and TGACG motif-binding transcription factors (TGAs), are known to mediate SA signaling, which might also be orchestrated by other hormonal and environmental changes. Nevertheless, the molecular and functional interactions between SA signaling components and other cellular signaling pathways remain poorly understood. Here we showed that the steroid plant hormone brassinosteroid (BR) promotes SA responses by inactivating BR-INSENSITIVE 2 (BIN2), which inhibits the redox-sensitive clade I TGAs in Arabidopsis. We found that both BR and the BIN2 inhibitor bikinin synergistically increase SA-mediated physiological responses, such as resistance to Pst DC3000. Our genetic and biochemical analyses indicated that BIN2 functionally interacts with TGA1 and TGA4, but not with other TGAs. We further demonstrated that BIN2 phosphorylates Ser-202 of TGA4, resulting in the suppression of the redox-dependent interaction between TGA4 and NPR1 as well as destabilization of TGA4. Consistently, transgenic Arabidopsis overexpressing TGA4-YFP with a S202A mutation displayed enhanced SA responses compared to the wild-type TGA4-YFP plants. Taken together, these results suggest a novel crosstalk mechanism by which BR signaling coordinates the SA responses mediated by redox-sensitive clade I TGAs.
基金supported by grant 31661143024 from the National Natural Science Foundation of China(to X.W.)grant 0120150092 from the Agricultural Research Outstanding Talents and Innovation Team of the Ministry of Agriculture(to X.W.).
文摘High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlying mechanisms remain obscure.Here,we demonstrate that the glycogen synthase kinase 3(GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2(BIN2),a negative component in the BR signaling pathway,interacts with the master heat-responsive transcription factors CLASS A1 HEAT SHOCK TRANSCRIPTION FACTORS(HsfA1s).Furthermore,BIN2 phosphorylates HsfA1d on T263 and S56 to suppress its nuclear localization and inhibit its DNA-binding ability,respectively.BR signaling promotes plant thermotolerance by releasing the BIN2 suppression of HsfA1d to facilitate its nuclear localization and DNA binding.Our study provides insights into the molecular mechanisms by which BRs promote plant thermotolerance by strongly regulating HsfA1d through BIN2 and suggests potential ways to improve crop yield under extreme high temperatures.
基金This work was supported by a grant from the National Science Foundation(ISO-1758932)awardedtoZ.M.
文摘It is well known that plantgrowth,development,and response to environmental stresses are harmonized through theaction of a suite of growth and defense signaling molecules.Brassinosteroid(BR)is a steroid hormone that regulates plant growth and development.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(Ministry of Science and ICT or Ministry of Education)(2021R1A2C1006617 and RS-2024-00407469 to T.-W.K.)supported by the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(2023R1A6C101A009 to T.-K.P.)the research fund of Hanyang University(HY-202200000003024 to T.-K.P.)。
文摘Stomata are epidermal pores that are essential for water evaporation and gas exchange in plants.Stomatal development is orchestrated by intrinsic developmental programs,hormonal controls,and environmental cues.The steroid hormone brassinosteroid(BR)inhibits stomatal lineage progression by regulating BIN2 and BSL proteins in leaves.Notably,BR is known to promote stomatal development in hypocotyls as opposed to leaves;however,its molecular mechanism remains elusive.Here,we show that BR signaling has a dual regulatory role in controlling stomatal development in Arabidopsis hypocotyls.We found that brassinolide(BL;the most active BR)regulates stomatal development differently in a concentration-dependent manner.At low and moderate concentrations,BL promoted stomatal formation by upregulating the expression of SPEECHLESS(SPCH)and its target genes independently of BIN2 regulation.In contrast,high concentrations of BL and bikinin,which is a specific inhibitor of BIN2 and its homologs,significantly reduced stomatal formation.Genetic analyses revealed that BIN2 regulates stomatal development in hypocotyls through molecular mechanisms distinct from the regulatory mechanism of the cotyledons.In hypocotyls,BIN2 promoted stomatal development by inactivating BZR1,which suppresses the expression of SPCH and its target genes.Taken together,our results suggest that BR precisely coordinates the stomatal development of hypocotyls using an antagonistic control of SPCH expression via BZR1-dependent and BZR1-independent transcriptional regulation.
文摘Cold stress is a major environmental factor that adversely affects plant growth and development. The C-repeat binding factor/DRE binding factor 1 （CBF/DREB1） transcriptional regulatory cascade has been shown to play important roles in plant response to cold. Here we demonstrate that two key components of brassinosteroid （BR） signaling modulate freezing tolerance of Arabidopsis plants. The loss-of-function mutant of the GSK3-1ike kinases involved in BR signaling, bin2-3 bill bil2, showed increased freezing tolerance, whereas overexpression of BIN2 resulted in hypersensitivity to freezing stress under both non-acclimated and acclimated conditions. By contrast, gain-of-function mutants of the transcription factors BZR1 and BES1 displayed enhanced freezing tolerance, and consistently cold treatment could induce the accumulation of dephosphorylated BZR1. Biochemical and genetic analyses showed that BZR1 acts upstream of CBF1 and CBF2 to directly regulate their expression. Moreover, we found that BZR1 also regulated other COR genes uncoupled with CBFs, such as WKRY6, PYL6, SOCl, JMT, and SAG21, to modulate plant response to cold stress. Consistently, wrky6 mutants showed decreased freezing tolerance. Taken together, our results indicate that BZR1 positively modulates plant freezing tolerance through CBF-dependent and CBF-independent pathways.
基金supported by the National Key Research and Development Program (2019YFD1001900)the National Natural Science Foundation of China (31872153,U21A20233)the Fundamental Research Funds for the Central Universities (2021FZZX001-30)。
文摘Brassinosteroids(BRs)and abscisic acid(ABA)are essential regulators of plant growth and stress tolerance.Although the antagonistic interaction of BRs and ABA is proposed to ensure the balance between growth and defense in model plants,the crosstalk between BRs and ABA in response to chilling in tomato(Solanum lycopersicum),a warmclimate horticultural crop,is unclear.Here,we determined that overexpression of the BR biosynthesis gene DWARF(DWF)or the key BR signaling gene BRASSINAZOLE-RESISTANT1(BZR1)increases ABA levels in response to chilling stress via positively regulating the expression of the ABA biosynthesis gene 9-CIS-EPOXYCAROTENOID DIOXYGENASE1(NCED1).BR-induced chilling tolerance was mostly dependent on ABA biosynthesis.Chilling stress or high BR levels decreased the abundance of BRASSINOSTEROID-INSENSITIVE2(BIN2),a negative regulator of BR signaling.Moreover,we observed that chilling stress increases BR levels and results in the accumulation of BZR1.BIN2negatively regulated both the accumulation of BZR1protein and chilling tolerance by suppressing ABA biosynthesis.Our results demonstrate that BR signaling positively regulates chilling tolerance via ABA biosynthesis in tomato.The study has implications in production of warm-climate crops in horticulture.
基金supported by grants from the National Natural Science Foundation of China(32270351 to C.H.,32325006 to M.-Y.B.,U24A20389 to M.-Y.B.,and 32461160287 to M.-Y.B.)Agricultural Variety Improvement Project of Shandong Province(2022LZGC001 to M.-Y.B.and 2024LZGC007 to M.F.)Science and Technology Department of Shandong Province(ZR2022YQ20 to C.H.).
文摘The balance between stem cell division and differentiation is crucial for flexible organ development.In Ara-bidopsis leaves,the fate of meristemoids,which exhibit stem cell characteristics,is tightly regulated by multiple intrinsic developmental signals and environmental factors.KiN1o,the catalytic subunit of the su-crose non-fermenting 1-related protein kinase 1(SnRK1)complex,has been shown to preferentially localize in the nucleus ofmeristemoids,where it phosphorylates and stabilizes the SPEECHLESS transcrip-tion factor,thereby promoting stomatal development.However,the regulatory mechanism governing the nuclear localization of KiN1o in meristemoids remains unclear.Here,we demonstrate that brassinosteroid(BR)inhibits KIN10's nuclear localization by modulating KINβ2 through BR-INSENSITIVE2(BIN2)-mediated phosphorylation.In meristemoids,KIN1o is predominantly nuclear,while KINp2 is mainly cytosolic.Inter-fering with the nuclear localization of KIN10 or enhancing the membrane association of KiNp2 impairs sto-matal development and leads to excessive epidermal cell proliferation.Cell biology and biochemical ana-lyses reveal that BR signaling could inhibit KIN10 nuclear localization by enhancing KIN2 membrane association,while BIN2 interacts with and phosphorylates KINp2 to reduce its membrane association and its interaction with KiN1o.Taken together,these findings suggest that the precise regulation of the subcellular localization of the SnRK1 complex,at least in part by BR signaling,is critical for meristemoid differentiation and stomatal development.
