Brassinosteroids( BRs),a group of polyhydroxylated plant steroid hormones,have fundamental functions in many aspects of plant growth and development. The BRI1-EMS SUPPRESSOR1( BES1) transcription factor is a positive ...Brassinosteroids( BRs),a group of polyhydroxylated plant steroid hormones,have fundamental functions in many aspects of plant growth and development. The BRI1-EMS SUPPRESSOR1( BES1) transcription factor is a positive regulator involved in BRs signaling pathways. We studied the role of At BES1D( obtained from bes1-D Arabidopsis) in tomato( Solanum lycopersicum) seed germination. Overexpression of At BES1D in tomato inhibited seed germination compared with wild type Zhongshusihao( ZS4). The expression of abscisic acid( ABA) related genes was enhanced in At BES1D transgenic tomato seeds during germination.Furthermore,At BES1D transgenic tomato seeds were hypersensitive to ABA. Our findings suggest that the inhibitory effect of At BES1D transcription factor on tomato seed germination may be correlated with an enhanced ABA pathway.展开更多
RAV1(Related to ABI3/VP1)is a plant-specific B3 and AP2 domain-containing transcription factor that acts as a negative regulator of growth in many plant species.The expression of RAV1 is downregulated by brassinostero...RAV1(Related to ABI3/VP1)is a plant-specific B3 and AP2 domain-containing transcription factor that acts as a negative regulator of growth in many plant species.The expression of RAV1 is downregulated by brassinosteroids(BRs);large-scale transcriptome analyses have shown that the expression of RAV1 was previously targeted by BRI1-EMS-SUPPRESOR1(BES1)and BRASSINAZOLE-RESISTANT1(BZR1),which are critical transcription factors for the BR-signaling process.Using RAV1-overexpressing transgenic plants,we showed that RAV1 overexpression reduced the BR signaling capacity,resulting in the downregulation of BR biosynthetic genes and BES1 expression.Furthermore,we demonstrated that BES1,not BZR1,is directly bound to the RAV1 promoter and repressed RAV1 expression,and vice versa;RAV1 is also bound to the BES1 promoter and repressed BES1 expression.This mutual inhibition was specific to RAV1 and BES1 because RAV1 exhibited binding activity to the BZR1 promoter but did not repress BZR1 expression.We observed that constitutively activated BR signaling phenotypes in bes1-D were attenuated by the repression of endogenous BES1 expression in transgenic bes1-D plants overexpressing RAV1.RNA-sequencing analysis of RAV1-overexpressing transgenic plants and bes1-D mutant plants revealed differentially expressed genes by RAV1 and BES1 and genes that were oppositely co-regulated by RAV1 and BES1.RAV1 and BES1 regulated different transcriptomes but co-regulated a specific set of genes responsible for the balance between growth and defense.These results suggested that the mutual inhibitory transcriptional activities of RAV1 and BES1 provide fine regulatory mechanisms for plant growth and development.展开更多
Brassinosteroids(BRs), which are essential phytohormones for plant growth and development, are important for cotton fiber development. Additionally, BES1 transcription factors are critical for BR signal transduction. ...Brassinosteroids(BRs), which are essential phytohormones for plant growth and development, are important for cotton fiber development. Additionally, BES1 transcription factors are critical for BR signal transduction. However, cotton BES1 family genes have not been comprehensively characterized. In this study, we identified 11 BES1 genes in G. arboreum, 11 in G.raimondii, 16 in G. barbadense, and 22 in G. hirsutum. The BES1 sequences were significantly conserved in the Arabidopsis thaliana, rice, and upland cotton genomes. A total of 94 BES1 genes from 10 different plant species were divided into three clades according to the neighbor-joining and minimum-evolution methods. Moreover, the exon/intron patterns and motif distributions were highly conserved among the A. thaliana and cotton BES1 genes. The collinearity among the orthologs from the At and Dt subgenomes was estimated. Segmental duplications in the At and Dt subgenomes were primarily responsible for the expansion of the cotton BES1 gene family. Of the GhBES1 genes, GhBES1.4_At/Dt exhibited BL-induced expression and was predominantly expressed in fibers. Furthermore, Col-0/mGhBES1.4_At plants produced curled leaves with long and bent petioles. These transgenic plants also exhibited decreased hypocotyl sensitivity to brassinazole and constitutive BR induced/repressed gene expression patterns. The constitutive BR responses of the plants overexpressing mGhBES1.4_At were similar to those of the bes1-D mutant.展开更多
Shoot branching,determining plant architecture and crop yield,is critically controlled by strigolactones(SLs).However,how SLs inhibit shoot branching after its perception by the receptor complex remains largely obscur...Shoot branching,determining plant architecture and crop yield,is critically controlled by strigolactones(SLs).However,how SLs inhibit shoot branching after its perception by the receptor complex remains largely obscure.In this study,using the transcriptomic and genetic analyss as well as biochemical studies,we reveal the key role of BES1 in the SL-regulated shoot branching.Wedemonstrate that BES1 and D53-like SMXLs,the substrates of SL receptor complex D14–MAX2,interact with each other to inhibit BRC1 expression,which specifically triggers the SL-regulated transcriptional network in shoot branching.BES1 directly binds the BRC1 promoter and recruits SMXLs to inhibit BRC1 expression.Interestingly,despite being the shared component by SL and brassinosteroid(BR)signaling,BES1 gains signal specificity through different mechanisms in response to BR and SL signals.展开更多
Brassinosteroids(BRs)are a group of steroidal phytohormones,playing critical roles in almost all physiological aspects during the life span of a plant.In Arabidopsis,BRs are perceived at the cell surface,triggering a ...Brassinosteroids(BRs)are a group of steroidal phytohormones,playing critical roles in almost all physiological aspects during the life span of a plant.In Arabidopsis,BRs are perceived at the cell surface,triggering a reversible phosphorylation-based signaling cascade that leads to the activation and nuclear accumulation of a family of transcription factors,represented by BES1 and BZR1.Protein famesylation is a type of post-translational modification,functioning in many important cellular processes.Previous studies demonstrated a role of famesylation in BR biosynthesis via regulating the endoplasmic reticulum localization of a key bassino-lide(BL)biosynthetic enzyme BR6ox2.Whether such a process is also involved in BR signaling is not understood.Here,we demonstrate that protein famesylation is involved in mediating BR signaling in Arabidopsis.A loss-of-function mutant of EN HANCED RESPONSE TO ABA 1(iERA1).encoding a(3 subunit of the protein famesyl transferase hoi oenzyme,can alter the BL sensitivity of bak1~4 from a reduced to a hypersensitive level,era 7 can partially rescue the BR defective phenotype of a hetero zygous mutant of bin2-1,a gain-of function mutant of BIN2 which encodes a negative regulator in the BR signaling.Our genetic and biochemical analyses revealed that ERA1 plays a significant role in regulating the protein stability of BES1.展开更多
As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S p...As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S proteasomal and autophagy pathways, which attenuate and terminate BR signaling;however,the opposing deubiquitinases (DUBs) are still unknown. Here, we showed that the ubp12-2w/13-3 doublemutant phenocopies the BR-deficient dwarf mutant, suggesting that the two DUBs UBP12/UBP13 antagonize ubiquitin-mediated degradation to stabilize BES1. These two DUBs can trim tetraubiquitin with K46 and K63 linkages in vitro. UBP12/BES1 and UBP13/BES1 complexes are localized in bothcytosol and nuclei. UBP12/13 can deubiquitinate polyubiquitinated BES1 in vitro and in planta, andUBP12 interacts with and deubiquitinates both inactive, phosphorylated BES1 and active, dephosphorylated BES1 in vivo. UBP12 overexpression in BES1OE plants significantly enhances cell elongation in hypocotyls and petioles and increases the ratio of leaf length to width compared with BES1OE or UBP12OE plants.Hypocotyl elongation and etiolation result from elevated BES1 levels because BES1 degradation is retardedby UBP12 in darkness or in light with BR. Protein degradation inhibitor experiments show that the majorityof BES1 can be degraded by either the proteasomal or the autophagy pathway, but a minor BES1 fractionremains pathway specific. In conclusion, UBP12/UBP13 deubiquitinate BES1 to stabilize the latter as a positive regulator for BR responses.展开更多
BRI1-EMS-SUPPRESSOR 1(BES1)transcription factor is closely associated with the brassinosteroid(BR)signaling pathway and plays an important role in plant growth and development.SLB3 is a member of BES1 transcription fa...BRI1-EMS-SUPPRESSOR 1(BES1)transcription factor is closely associated with the brassinosteroid(BR)signaling pathway and plays an important role in plant growth and development.SLB3 is a member of BES1 transcription factor family and its expression was previously shown to increase significantly in tomato seedlings under drought stress.In the present study,we used virus-induced gene silencing(VIGS)technology to downregulate SLB3 expression to reveal the function of the SLB3 gene under drought stress further.The downregulated expression of SLB3 weakened the drought tolerance of the plants appeared earlier wilting and higher accumulation of H2 O2 and O2^–·,decreased superoxide dismutase(SOD)activity,and increased proline(PRO)and malondialdehyde(MDA)contents and peroxidase(POD)activity.Quantitative real-time PCR(qRT-PCR)analysis of BR-related genes revealed that the expression of SlCPD,SlDWARF and BIN2-related genes was significantly upregulated in SLB3-silenced seedlings under drought stress,but that the expression of TCH4-related genes was downregulated.These results showed that silencing the SLB3 gene reduced the drought resistance of tomato plants and had an impact on the BR signaling transduction which may be probably responsible for the variation in drought resistance of the tomato plants.展开更多
基金Supported by National Undergraduate Training Program for Innovation and Entrepreneurship (2018A8205)。
文摘Brassinosteroids( BRs),a group of polyhydroxylated plant steroid hormones,have fundamental functions in many aspects of plant growth and development. The BRI1-EMS SUPPRESSOR1( BES1) transcription factor is a positive regulator involved in BRs signaling pathways. We studied the role of At BES1D( obtained from bes1-D Arabidopsis) in tomato( Solanum lycopersicum) seed germination. Overexpression of At BES1D in tomato inhibited seed germination compared with wild type Zhongshusihao( ZS4). The expression of abscisic acid( ABA) related genes was enhanced in At BES1D transgenic tomato seeds during germination.Furthermore,At BES1D transgenic tomato seeds were hypersensitive to ABA. Our findings suggest that the inhibitory effect of At BES1D transcription factor on tomato seed germination may be correlated with an enhanced ABA pathway.
基金supported by grants from the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT,and Future Planning(NRF-2017R1A2B4002656 and 2020R1F1A1067946 to K.H.N.and 2021R1A6A3A13045111 to D.Y.)。
文摘RAV1(Related to ABI3/VP1)is a plant-specific B3 and AP2 domain-containing transcription factor that acts as a negative regulator of growth in many plant species.The expression of RAV1 is downregulated by brassinosteroids(BRs);large-scale transcriptome analyses have shown that the expression of RAV1 was previously targeted by BRI1-EMS-SUPPRESOR1(BES1)and BRASSINAZOLE-RESISTANT1(BZR1),which are critical transcription factors for the BR-signaling process.Using RAV1-overexpressing transgenic plants,we showed that RAV1 overexpression reduced the BR signaling capacity,resulting in the downregulation of BR biosynthetic genes and BES1 expression.Furthermore,we demonstrated that BES1,not BZR1,is directly bound to the RAV1 promoter and repressed RAV1 expression,and vice versa;RAV1 is also bound to the BES1 promoter and repressed BES1 expression.This mutual inhibition was specific to RAV1 and BES1 because RAV1 exhibited binding activity to the BZR1 promoter but did not repress BZR1 expression.We observed that constitutively activated BR signaling phenotypes in bes1-D were attenuated by the repression of endogenous BES1 expression in transgenic bes1-D plants overexpressing RAV1.RNA-sequencing analysis of RAV1-overexpressing transgenic plants and bes1-D mutant plants revealed differentially expressed genes by RAV1 and BES1 and genes that were oppositely co-regulated by RAV1 and BES1.RAV1 and BES1 regulated different transcriptomes but co-regulated a specific set of genes responsible for the balance between growth and defense.These results suggested that the mutual inhibitory transcriptional activities of RAV1 and BES1 provide fine regulatory mechanisms for plant growth and development.
基金supported by the National Natural Science Foundation of China (31501345)Young Elite Scientist Sponsorship Program by CAST (China Association for Science and Technology)
文摘Brassinosteroids(BRs), which are essential phytohormones for plant growth and development, are important for cotton fiber development. Additionally, BES1 transcription factors are critical for BR signal transduction. However, cotton BES1 family genes have not been comprehensively characterized. In this study, we identified 11 BES1 genes in G. arboreum, 11 in G.raimondii, 16 in G. barbadense, and 22 in G. hirsutum. The BES1 sequences were significantly conserved in the Arabidopsis thaliana, rice, and upland cotton genomes. A total of 94 BES1 genes from 10 different plant species were divided into three clades according to the neighbor-joining and minimum-evolution methods. Moreover, the exon/intron patterns and motif distributions were highly conserved among the A. thaliana and cotton BES1 genes. The collinearity among the orthologs from the At and Dt subgenomes was estimated. Segmental duplications in the At and Dt subgenomes were primarily responsible for the expansion of the cotton BES1 gene family. Of the GhBES1 genes, GhBES1.4_At/Dt exhibited BL-induced expression and was predominantly expressed in fibers. Furthermore, Col-0/mGhBES1.4_At plants produced curled leaves with long and bent petioles. These transgenic plants also exhibited decreased hypocotyl sensitivity to brassinazole and constitutive BR induced/repressed gene expression patterns. The constitutive BR responses of the plants overexpressing mGhBES1.4_At were similar to those of the bes1-D mutant.
基金Supported by NSFC 31430046(to X.W),31661143024(to X.W.)National Key Research and Development Plan 2016YFD0100403(to S.S.)+1 种基金the Ministry of Agriculture Innovation team plan(0120150092 to X.W.)the School Independent Scientific and Technological Innovation Foundation and Research Startup Foundation of Huazhong Agricultural University(2662015PY020 and 2014RC002 to X.W.).
文摘Shoot branching,determining plant architecture and crop yield,is critically controlled by strigolactones(SLs).However,how SLs inhibit shoot branching after its perception by the receptor complex remains largely obscure.In this study,using the transcriptomic and genetic analyss as well as biochemical studies,we reveal the key role of BES1 in the SL-regulated shoot branching.Wedemonstrate that BES1 and D53-like SMXLs,the substrates of SL receptor complex D14–MAX2,interact with each other to inhibit BRC1 expression,which specifically triggers the SL-regulated transcriptional network in shoot branching.BES1 directly binds the BRC1 promoter and recruits SMXLs to inhibit BRC1 expression.Interestingly,despite being the shared component by SL and brassinosteroid(BR)signaling,BES1 gains signal specificity through different mechanisms in response to BR and SL signals.
基金supported by the National Natural Sci-ence Foundation of China Grants 31720103902 ,32030005(to J.L.)111 Project B16022(to J.L.)the Funda-mental Research Funds for the Central Universities Grant no.lzujbky‐2020‐sp04(to J.L.),lzujbky‐2021‐kb05。
文摘Brassinosteroids(BRs)are a group of steroidal phytohormones,playing critical roles in almost all physiological aspects during the life span of a plant.In Arabidopsis,BRs are perceived at the cell surface,triggering a reversible phosphorylation-based signaling cascade that leads to the activation and nuclear accumulation of a family of transcription factors,represented by BES1 and BZR1.Protein famesylation is a type of post-translational modification,functioning in many important cellular processes.Previous studies demonstrated a role of famesylation in BR biosynthesis via regulating the endoplasmic reticulum localization of a key bassino-lide(BL)biosynthetic enzyme BR6ox2.Whether such a process is also involved in BR signaling is not understood.Here,we demonstrate that protein famesylation is involved in mediating BR signaling in Arabidopsis.A loss-of-function mutant of EN HANCED RESPONSE TO ABA 1(iERA1).encoding a(3 subunit of the protein famesyl transferase hoi oenzyme,can alter the BL sensitivity of bak1~4 from a reduced to a hypersensitive level,era 7 can partially rescue the BR defective phenotype of a hetero zygous mutant of bin2-1,a gain-of function mutant of BIN2 which encodes a negative regulator in the BR signaling.Our genetic and biochemical analyses revealed that ERA1 plays a significant role in regulating the protein stability of BES1.
基金This work was supported in part by an RSSS grant(no.NRF-RSSS-002)to N.-H.C.from the National Research Foundation,Singapore.
文摘As a key transcription factor in the brassinosteroid (BR) signaling pathway, the activity and expression ofBES1 (BRI1-EMS-SUPPRESSOR 1) are stringently regulated. BES1 degradation is mediated by ubiquitinrelated 26S proteasomal and autophagy pathways, which attenuate and terminate BR signaling;however,the opposing deubiquitinases (DUBs) are still unknown. Here, we showed that the ubp12-2w/13-3 doublemutant phenocopies the BR-deficient dwarf mutant, suggesting that the two DUBs UBP12/UBP13 antagonize ubiquitin-mediated degradation to stabilize BES1. These two DUBs can trim tetraubiquitin with K46 and K63 linkages in vitro. UBP12/BES1 and UBP13/BES1 complexes are localized in bothcytosol and nuclei. UBP12/13 can deubiquitinate polyubiquitinated BES1 in vitro and in planta, andUBP12 interacts with and deubiquitinates both inactive, phosphorylated BES1 and active, dephosphorylated BES1 in vivo. UBP12 overexpression in BES1OE plants significantly enhances cell elongation in hypocotyls and petioles and increases the ratio of leaf length to width compared with BES1OE or UBP12OE plants.Hypocotyl elongation and etiolation result from elevated BES1 levels because BES1 degradation is retardedby UBP12 in darkness or in light with BR. Protein degradation inhibitor experiments show that the majorityof BES1 can be degraded by either the proteasomal or the autophagy pathway, but a minor BES1 fractionremains pathway specific. In conclusion, UBP12/UBP13 deubiquitinate BES1 to stabilize the latter as a positive regulator for BR responses.
基金This research was supported by the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province,China(UNPYSCT-2018169)the China Postdoctoral Science Foundation Grant(2018 M630333)+1 种基金the National Key R&D Program of China(2017YFD0101900)the earmarked fund for China Agriculture Research System(CARS-23-A-16).
文摘BRI1-EMS-SUPPRESSOR 1(BES1)transcription factor is closely associated with the brassinosteroid(BR)signaling pathway and plays an important role in plant growth and development.SLB3 is a member of BES1 transcription factor family and its expression was previously shown to increase significantly in tomato seedlings under drought stress.In the present study,we used virus-induced gene silencing(VIGS)technology to downregulate SLB3 expression to reveal the function of the SLB3 gene under drought stress further.The downregulated expression of SLB3 weakened the drought tolerance of the plants appeared earlier wilting and higher accumulation of H2 O2 and O2^–·,decreased superoxide dismutase(SOD)activity,and increased proline(PRO)and malondialdehyde(MDA)contents and peroxidase(POD)activity.Quantitative real-time PCR(qRT-PCR)analysis of BR-related genes revealed that the expression of SlCPD,SlDWARF and BIN2-related genes was significantly upregulated in SLB3-silenced seedlings under drought stress,but that the expression of TCH4-related genes was downregulated.These results showed that silencing the SLB3 gene reduced the drought resistance of tomato plants and had an impact on the BR signaling transduction which may be probably responsible for the variation in drought resistance of the tomato plants.
