It is known that the high level of sugar including glucose suppresses seed germination through ABA signal.ABI5 is an essential component to mediate ABA-dependent seed germination inhibition,but underlying mechanism ne...It is known that the high level of sugar including glucose suppresses seed germination through ABA signal.ABI5 is an essential component to mediate ABA-dependent seed germination inhibition,but underlying mechanism needs more investigation.Previous study demonstrated the PIF4 activated the expression of ABI5 to suppress seed germination in darkness.Here we reported that PIF4 also mediated the seed germination inhibition through ABI5 under high concentration of glucose treatment.Furthermore,we found that PIF4 interacted with PAP1,the central factor to control anthocyanin biosynthesis.Such interaction was confirmed in vitro and in planta.Biochemical and physiological analysis revealed that PAP1 bond the promoter of ABI5 to suppress its expression,thus enhanced seed germination under high concentration of glucose treatment.Specially,PAP1 competed with PIF4 to antagonize the activation of PIF4 on ABI5 expression,thus promoted seed germination under high glucose treatment.Given these,we uncover a novel role for PIF4 and PAP1 in controlling seed germination under high glucose treatment,and reveal their antagonistic mechanism by which coordinates ABI5 expression to control seed germination in response to the glucose signal.展开更多
Transcriptional regulation plays a key role in the control of seed dormancy,and many transcription factors(TFs)have been documented.However,the mechanisms underlying the interactions between different TFs within a tra...Transcriptional regulation plays a key role in the control of seed dormancy,and many transcription factors(TFs)have been documented.However,the mechanisms underlying the interactions between different TFs within a transcriptional complex regulating seed dormancy remain largely unknown.Here,we showed that TF PHYTOCHROME-INTERACTING FACTOR4(PIF4)physically interacted with the abscisic acid(ABA)signaling responsive TF ABSCISIC ACID INSENSITIVE4(ABI4)to act as a transcriptional complex to promote ABA biosynthesis and signaling,finally deepening primary seed dormancy.Both pif4 and abi4 single mutants exhibited a decreased primary seed dormancy phenotype,with a synergistic effect in the pif4/abi4 double mutant.PIF4 binds to ABI4 to form a heterodimer,and ABI4 stabilizes PIF4 at the protein level,whereas PIF4 does not affect the protein stabilization of ABI4.Subsequently,both TFs independently and synergistically promoted the expression of ABI4 and NCED6,a key gene for ABA anabolism.The genetic evidence is also consistent with the phenotypic,physiological and biochemical analysis results.Altogether,this study revealed a transcriptional regulatory cascade in which the PIF4–ABI4 transcriptional activator complex synergistically enhanced seed dormancy by facilitating ABA biosynthesis and signaling.展开更多
The molecular mechanism underlying phototherapy and light treatment,which utilize various wavelength spectra of light,including near-infrared(NIR),to cure human and plant diseases,is obscure.Here we re-vealed that NIR...The molecular mechanism underlying phototherapy and light treatment,which utilize various wavelength spectra of light,including near-infrared(NIR),to cure human and plant diseases,is obscure.Here we re-vealed that NIR light confers antiviral immunity by positively regulating PHYTOCHROME-INTERACTING FACTOR 4(PIF4)-activated RNA interference(RNAi)in plants.PIF4,a central transcription factor involved in light signaling,accumulates to high levels under NIR light in plants.PIF4 directly induces the transcription of two essential components of RNAi,RNA-DEPENDENT RNA POLYMERASE 6(RDR6)and ARGONAUTE 1(AGO1),which play important roles in resistance to both DNA and RNA viruses.Moreover,the pathogenic determinant bC1 protein,which is evolutionarily conserved and encoded by betasatellites,interacts with PIF4 and inhibits its positive regulation of RNAi by disrupting PIF4 dimerization.Thesefindings shed light on the molecular mechanism of PIF4-mediated plant defense and provide a new perspective for the explo-ration of NIR antiviral treatment.展开更多
ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be invo...ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be involved in regulating seedling photomorphogenesis;however,the underlying mechanism remains elusive.Here,we show that the role of ABI4 in regulating photomorphogenesis is generally regulated by sucrose,but ABI4 promotes hypocotyl elongation of Arabidopsis seedlings under blue(B) light under all tested sucrose concentrations.We further show that ABI4 physically interacts with PHYTOCHROME INTERACTING FACTOR 4(PIF4),a well-characterized growth-promoting transcription factor,and post-translationally promotes PIF4 protein accumulation under B light.Further analyses indicate that ABI4 directly interacts with the B light photoreceptors cryptochromes(CRYs) and inhibits the interactions between CRYs and PIF4,thus relieving CRY-mediated repression of PIF4 protein accumulation.In addition,while ABI4 could directly activate its own expression,CRYs enhance,whereas PIF4 inhibits,ABI4-mediated activation of the ABI4 promoter.Together,our study demonstrates that the ABI4–PIF4 module plays an important role in mediating CRY-induced B light signaling in Arabidopsis.展开更多
Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR...Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR 4(PIF4).Here,we show that warmth promotes the nighttime transcription of GI,which is necessary for the high temperature-induced transcription of TOC1.Genetic analyses suggest that GI prevents excessive thermoresponsive growth by inhibiting PIF4,with this regulatory mechanism be-ing partially reliant on TOC1.GI transcription is repressed by ELF3 and HY5,which concurrently inhibit PIF4 expression and activity.Temperature elevation causes the deactivation or degradation of ELF3 and HY5,leading to PIF4 activation and relief of GI transcriptional repression at high temperatures.This allows PIF4 to further activate GI transcription in response to elevated temperatures.GI,in turn,inhibits PIF4,es-tablishing a negative feedback loop thatfine-tunes PIF4 activity.In addition,we demonstrate that ELF3,HY5,and PIF4 regulate GI transcription by modulating the enrichment of histone variant H2A.Z at the GI lo-cus.Together,ourfindings suggest that thermal release of a negative feedback loopfinely adjusts plant thermomorphogenesis.展开更多
Plants continuously monitor environmental conditions (such as light and temperature) and adjust their growth and development accordingly. The transcription factor PHYTOCHROME-INTERACTING FACTOR4 (PIF4) regulates b...Plants continuously monitor environmental conditions (such as light and temperature) and adjust their growth and development accordingly. The transcription factor PHYTOCHROME-INTERACTING FACTOR4 (PIF4) regulates both light and temperature signaling pathways. Here, we identified ENHANCED PHOTOMORPHOGENIC2 (EPP2) as a new repressor of photomorphogenesis in red, far-red, and blue light. Map-based cloning revealed that EPP2 encodes the SEUSS (SEU) transcription regulator. The C terminus of SEU has transcriptional activation activity, and SEU physically interacts with PIF4. Moreover, SEU promotes the expression of many genes, including auxin biosynthetic and responsive genes, and regulates IAA levels in plants. SEU associates with the regulatory regions of INDOLE-3-ACETIC ACID INDUCIBLE6 (IAA6) and IAA 19 in a PIF4-independent manner, whereas the binding of PIF4to these genes requires SEU. Furthermore, muta- tions in SEU affect H3K4me3 methylation at IAA6 and IAA 19, and SEU positively regulates warm temperature- mediated hypocotyl growth together with PIF4. Collectively, our results reveal that SEU acts as a central regulator integrating light and temperature signals to control plant growth by coordinating with PIF4.展开更多
Upon exposure to light, developing seedlings undergo photomorphogenesis, as illustrated by inhibition of hypocotyl elongation, cotyledon opening, and leaf greening. During hypocotyl photomorphogenesis, light signals a...Upon exposure to light, developing seedlings undergo photomorphogenesis, as illustrated by inhibition of hypocotyl elongation, cotyledon opening, and leaf greening. During hypocotyl photomorphogenesis, light signals are sensed by multiple photoreceptors, among which the red/far-red light-sensing phytochromes have been extensively studied. However, it is not fully understood how the phytochromes modulate hypo- cotyl growth. Here, we demonstrated that HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1), which is known to either act as E3 ubiquitin ligase or affect chromatin organization, inhibits the transcriptional activation activity of PHYTOCHROME INTERACTING FACTOR 4 (PIF4), a key transcrip- tion factor that promotes hypocotyl growth. Consistent with the negative regulatory role of HOSl in hypo- cotyl growth, HOSl-defective mutants exhibited elongated hypocotyls in the light. Notably, phyB induces HOS1 activity in inhibiting PIF4 function. Taken together, these observations provide a molecular basis for the phyB-mediated suppression of hypocotyl growth in Arabidopsis.展开更多
phytochrome B(phyB)acts as the red light photoreceptor and negatively regulates the growth-promoting factor PHYTOCHROME INTERACTING 4(PIF4)through a direct physical interaction,which in turn changes the expression of ...phytochrome B(phyB)acts as the red light photoreceptor and negatively regulates the growth-promoting factor PHYTOCHROME INTERACTING 4(PIF4)through a direct physical interaction,which in turn changes the expression of a large number of genes.phyB-PIF4 module regulates a variety of biological and developmental processes in plants.In this study,we demonstrate that B-BOX PROTEIN 11(BBX11)physically interacts with both phyB and PIF4.BBX11 negatively regulates PIF4 accumulation as well as its biochemical activity,consequently leading to the repression of PIF4-controlled genes’expression and promotion of photomorphogenesis in the prolonged red light.This study reveals a regulatory mechanism that mediates red light signal transduction and sheds a light on phyB-PIF4 module in promoting red light-dependent photomorphognenesis.展开更多
Light signaling precisely controls photomorphogenic development in plants.PHYTOCHROME INTERACTING FACTOR 4 and 5(PIF4 and PIF5)play critical roles in the regulation of this developmental process.In this study,we repor...Light signaling precisely controls photomorphogenic development in plants.PHYTOCHROME INTERACTING FACTOR 4 and 5(PIF4 and PIF5)play critical roles in the regulation of this developmental process.In this study,we report CONSTITUTIVELY PHOTOMORPHOGENIC 1 SUPPRESSOR 6(CSU6)functions as a key regulator of light signaling.Loss of CSU6 function largely rescues the cop1-6 constitutively photomorphogenic phenotype.CSU6 promotes hypocotyl growth in the dark,but inhibits hypocotyl elongation in the light.CSU6 not only associates with the promoter regions of PIF4 and PIF5 to inhibit their expression in the morning,but also directly interacts with both PIF4 and PIF5 to repress their transcriptional activation activity.CSU6 negatively controls a group of PIF4-and PIF5-regulated gene expressions.Mutations in PIF4 and/or PIF5 are epistatic to the loss of CSU6,suggesting that CSU6 acts upstream of PIF4 and PIF5.Taken together,CSU6 promotes light-inhibited hypocotyl elongation by negatively regulating PIF4 and PIF5 transcription and biochemical activity.展开更多
Arabidopsis CONSTITUTIVELY PHOTOMORPHO GENIC1(COP1)and PHYTOCHROME INTERACTING FACTORs(PIFs)are negative regulators,and ELONGATED HYPOCOTYL5(HY5)is a positive regulator of seedling photomorphogenic development.Here,we...Arabidopsis CONSTITUTIVELY PHOTOMORPHO GENIC1(COP1)and PHYTOCHROME INTERACTING FACTORs(PIFs)are negative regulators,and ELONGATED HYPOCOTYL5(HY5)is a positive regulator of seedling photomorphogenic development.Here,we report that SICKLE(SIC),a proline rich protein,acts as a novel negative regulator of photomorphogenesis.HY5 directly binds the SIC promoter and activates SIC expression in response to light.In turn,SIC physically interacts with HY5 and interferes with its transcriptional regulation of downstream target genes.Moreover,SIC interacts with PIF4 and promotes PIF4-activated transcription of itself.Interestingly,SIC is targeted by COP1 for 26S proteasomemediated degradation in the dark.Collectively,our data demonstrate that light-induced SIC functions as a brake to prevent exaggerated light response via mediating HY5 and PIF4 signaling,and its degradation by COP1 in the dark avoid too strong inhibition on photomorphogenesis at the beginning of light exposure.展开更多
WRKY transcription factors are known mostly for their function in plant defense,abiotic stress responses,senescence,seed germination,and development of the pollen,embryo,and seed.Here,we report the regulatory function...WRKY transcription factors are known mostly for their function in plant defense,abiotic stress responses,senescence,seed germination,and development of the pollen,embryo,and seed.Here,we report the regulatory functions of two WRKY proteins in photomorphogenesis and PIF4 expression.PIF4 is a critical signaling hub in light,temperature,and hormonal signaling pathways.Either its expression or its accumulation peaks in the morning and afternoon.WRKY2 and WRKY10 form heterodimers and recognize their target site in the PIF4 promoter near the MYB element that is bound by CCA1 and LHY under red and blue light.WRKY2 and WRKY10 interact directly with CCA1/LHY to enhance their targeting but interact indirectly with SHB1.The two WRKY proteins also interact with phyB,and their interaction enhances the targeting of CCA1 and LHY to the PIF4 promoter.SHB1 associates with theWRKY2 andWRKY10 loci and enhances their expression in parallel with the PIF4 expression peaks.This forward regulatory loop further sustains the accumulation of the two WRKY proteins and the targeting of CCA1/LHY to the PIF4 locus.In summary,interactions of two WRKY proteins with CCA1/LHY and phyB maintain an optimal expression level of PIF4 toward noon and afternoon,which is essential to sketch the circadian pattern of PIF4 expression.展开更多
High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recen...High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recently reported positive regulator of thermomorphogenesis,but the molecular mechanisms by which HLS1 regulates thermomorphogenesis remain unknown.In this study,we initially compared PIF4-and/or HLS1-dependent differential gene expression(DEG)upon high-temperature treatment.We found that a large number of genes are coregulated by PIF4 and HLS1,especially genes involved in plant growth or defense responses.Moreover,we found that HLS1 interacts with PIF4 to form a regulatory module and that,among the HLS1-PIF4-coregulated genes,27.7%are direct targets of PIF4.We also identified 870 differentially alternatively spliced genes(DASGs)in wild-type plants under high temperature.Interestingly,more than half of these DASG events(52.4%)are dependent on both HLS1 and PIF4,and the spliceosome-defective mutant plantsexhibit a hyposensitive response to high temperature,indicating that DASGs are required for thermomorphogenesis.Further comparative analyses showed that the HLS1/PIF4-coregulated DEGs and DASGs exhibit almost no overlap,suggesting that high temperature triggers two distinct strategies to control plant responses and thermomorphogenesis.Taken together,these results demonstrate that the HLS1-PIF4 module precisely controls both transcriptional and posttranscriptional regulation during plant thermomorphogenesis.展开更多
(Molecular Plant 11(7):928-942;July 2018;https://doi.Org/10.1016/j.molp.2018.04.005)In the Abstract of this article,there is an error in the sentence"SEU associates with the regulatory regions of INDOLE-3-ACETIC ...(Molecular Plant 11(7):928-942;July 2018;https://doi.Org/10.1016/j.molp.2018.04.005)In the Abstract of this article,there is an error in the sentence"SEU associates with the regulatory regions of INDOLE-3-ACETIC ACID INDUCIBLE6(IAA6)and IAA19 in a PIF4-independent manner,whereas the binding of PIF4 to these genes requires SEU.Furthermore.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.31970289).
文摘It is known that the high level of sugar including glucose suppresses seed germination through ABA signal.ABI5 is an essential component to mediate ABA-dependent seed germination inhibition,but underlying mechanism needs more investigation.Previous study demonstrated the PIF4 activated the expression of ABI5 to suppress seed germination in darkness.Here we reported that PIF4 also mediated the seed germination inhibition through ABI5 under high concentration of glucose treatment.Furthermore,we found that PIF4 interacted with PAP1,the central factor to control anthocyanin biosynthesis.Such interaction was confirmed in vitro and in planta.Biochemical and physiological analysis revealed that PAP1 bond the promoter of ABI5 to suppress its expression,thus enhanced seed germination under high concentration of glucose treatment.Specially,PAP1 competed with PIF4 to antagonize the activation of PIF4 on ABI5 expression,thus promoted seed germination under high glucose treatment.Given these,we uncover a novel role for PIF4 and PAP1 in controlling seed germination under high glucose treatment,and reveal their antagonistic mechanism by which coordinates ABI5 expression to control seed germination in response to the glucose signal.
基金supported by the National Natural Science Foundation of China(31872804 and 32101670)Natural Science Basic Research Program of Shaanxi(2024JC-YBMS-151)+3 种基金Shaanxi Fundamental Science Research Project for Chemistry&Biology(22JHQ054 and 22JHZ007)GuangDong Basic and Applied Basic Research Foundation(2021A1515110341)the Innovation Foundation for Doctoral Dissertations of Northwestern Polytechnical University(CX2021040,CX2022079 and CX2023096)Postdoctoral Research Foundation of China(2021M692644,2021M702674)。
文摘Transcriptional regulation plays a key role in the control of seed dormancy,and many transcription factors(TFs)have been documented.However,the mechanisms underlying the interactions between different TFs within a transcriptional complex regulating seed dormancy remain largely unknown.Here,we showed that TF PHYTOCHROME-INTERACTING FACTOR4(PIF4)physically interacted with the abscisic acid(ABA)signaling responsive TF ABSCISIC ACID INSENSITIVE4(ABI4)to act as a transcriptional complex to promote ABA biosynthesis and signaling,finally deepening primary seed dormancy.Both pif4 and abi4 single mutants exhibited a decreased primary seed dormancy phenotype,with a synergistic effect in the pif4/abi4 double mutant.PIF4 binds to ABI4 to form a heterodimer,and ABI4 stabilizes PIF4 at the protein level,whereas PIF4 does not affect the protein stabilization of ABI4.Subsequently,both TFs independently and synergistically promoted the expression of ABI4 and NCED6,a key gene for ABA anabolism.The genetic evidence is also consistent with the phenotypic,physiological and biochemical analysis results.Altogether,this study revealed a transcriptional regulatory cascade in which the PIF4–ABI4 transcriptional activator complex synergistically enhanced seed dormancy by facilitating ABA biosynthesis and signaling.
基金supported by the National Natural Science Foundation of China,China (32125032,31830073,and 31901853).
文摘The molecular mechanism underlying phototherapy and light treatment,which utilize various wavelength spectra of light,including near-infrared(NIR),to cure human and plant diseases,is obscure.Here we re-vealed that NIR light confers antiviral immunity by positively regulating PHYTOCHROME-INTERACTING FACTOR 4(PIF4)-activated RNA interference(RNAi)in plants.PIF4,a central transcription factor involved in light signaling,accumulates to high levels under NIR light in plants.PIF4 directly induces the transcription of two essential components of RNAi,RNA-DEPENDENT RNA POLYMERASE 6(RDR6)and ARGONAUTE 1(AGO1),which play important roles in resistance to both DNA and RNA viruses.Moreover,the pathogenic determinant bC1 protein,which is evolutionarily conserved and encoded by betasatellites,interacts with PIF4 and inhibits its positive regulation of RNAi by disrupting PIF4 dimerization.Thesefindings shed light on the molecular mechanism of PIF4-mediated plant defense and provide a new perspective for the explo-ration of NIR antiviral treatment.
基金supported by grants from the National Natural Science Foundation of China(32225006)the Beijing Natural Science Foundation(5232011)+1 种基金the Chinese Universities Scientific Fund(2024TC166)by the Postdoctoral Fel owship Program of CPSF under Grant Number GZC20230717。
文摘ABSCISIC ACID-INSENSITIVE 4(ABI4) is a pivotal transcription factor which coordinates multiple aspects of plant growth and development as well as plant responses to environmental stresses.ABI4has been shown to be involved in regulating seedling photomorphogenesis;however,the underlying mechanism remains elusive.Here,we show that the role of ABI4 in regulating photomorphogenesis is generally regulated by sucrose,but ABI4 promotes hypocotyl elongation of Arabidopsis seedlings under blue(B) light under all tested sucrose concentrations.We further show that ABI4 physically interacts with PHYTOCHROME INTERACTING FACTOR 4(PIF4),a well-characterized growth-promoting transcription factor,and post-translationally promotes PIF4 protein accumulation under B light.Further analyses indicate that ABI4 directly interacts with the B light photoreceptors cryptochromes(CRYs) and inhibits the interactions between CRYs and PIF4,thus relieving CRY-mediated repression of PIF4 protein accumulation.In addition,while ABI4 could directly activate its own expression,CRYs enhance,whereas PIF4 inhibits,ABI4-mediated activation of the ABI4 promoter.Together,our study demonstrates that the ABI4–PIF4 module plays an important role in mediating CRY-induced B light signaling in Arabidopsis.
基金supported by the National Natural Science Foundation of China (32150610472)the National Key R&D Program of China (2019YFA0903903).
文摘Plants can sense temperature changes and adjust their growth accordingly.In Arabidopsis,high ambient temperatures stimulate stem elongation by activating a key thermoresponsive regulator,PHYTOCHROME INTERACTING FACTOR 4(PIF4).Here,we show that warmth promotes the nighttime transcription of GI,which is necessary for the high temperature-induced transcription of TOC1.Genetic analyses suggest that GI prevents excessive thermoresponsive growth by inhibiting PIF4,with this regulatory mechanism be-ing partially reliant on TOC1.GI transcription is repressed by ELF3 and HY5,which concurrently inhibit PIF4 expression and activity.Temperature elevation causes the deactivation or degradation of ELF3 and HY5,leading to PIF4 activation and relief of GI transcriptional repression at high temperatures.This allows PIF4 to further activate GI transcription in response to elevated temperatures.GI,in turn,inhibits PIF4,es-tablishing a negative feedback loop thatfine-tunes PIF4 activity.In addition,we demonstrate that ELF3,HY5,and PIF4 regulate GI transcription by modulating the enrichment of histone variant H2A.Z at the GI lo-cus.Together,ourfindings suggest that thermal release of a negative feedback loopfinely adjusts plant thermomorphogenesis.
文摘Plants continuously monitor environmental conditions (such as light and temperature) and adjust their growth and development accordingly. The transcription factor PHYTOCHROME-INTERACTING FACTOR4 (PIF4) regulates both light and temperature signaling pathways. Here, we identified ENHANCED PHOTOMORPHOGENIC2 (EPP2) as a new repressor of photomorphogenesis in red, far-red, and blue light. Map-based cloning revealed that EPP2 encodes the SEUSS (SEU) transcription regulator. The C terminus of SEU has transcriptional activation activity, and SEU physically interacts with PIF4. Moreover, SEU promotes the expression of many genes, including auxin biosynthetic and responsive genes, and regulates IAA levels in plants. SEU associates with the regulatory regions of INDOLE-3-ACETIC ACID INDUCIBLE6 (IAA6) and IAA 19 in a PIF4-independent manner, whereas the binding of PIF4to these genes requires SEU. Furthermore, muta- tions in SEU affect H3K4me3 methylation at IAA6 and IAA 19, and SEU positively regulates warm temperature- mediated hypocotyl growth together with PIF4. Collectively, our results reveal that SEU acts as a central regulator integrating light and temperature signals to control plant growth by coordinating with PIF4.
文摘Upon exposure to light, developing seedlings undergo photomorphogenesis, as illustrated by inhibition of hypocotyl elongation, cotyledon opening, and leaf greening. During hypocotyl photomorphogenesis, light signals are sensed by multiple photoreceptors, among which the red/far-red light-sensing phytochromes have been extensively studied. However, it is not fully understood how the phytochromes modulate hypo- cotyl growth. Here, we demonstrated that HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1), which is known to either act as E3 ubiquitin ligase or affect chromatin organization, inhibits the transcriptional activation activity of PHYTOCHROME INTERACTING FACTOR 4 (PIF4), a key transcrip- tion factor that promotes hypocotyl growth. Consistent with the negative regulatory role of HOSl in hypo- cotyl growth, HOSl-defective mutants exhibited elongated hypocotyls in the light. Notably, phyB induces HOS1 activity in inhibiting PIF4 function. Taken together, these observations provide a molecular basis for the phyB-mediated suppression of hypocotyl growth in Arabidopsis.
基金by a grant from the National Natural Science Foundation of China(31970258)by start-up funding from Nan-jing Agricultural University(to D.X.)+2 种基金by grants from Jiangsu‘‘In-novative and Entrepreneurial Talent’’program(to D.X.)Nanjing Science and Technology Innovation Program for Overseas Stu-dents(to D.X.)the Jiangsu Collaborative Innovation Center for Modern Crop Production.
文摘phytochrome B(phyB)acts as the red light photoreceptor and negatively regulates the growth-promoting factor PHYTOCHROME INTERACTING 4(PIF4)through a direct physical interaction,which in turn changes the expression of a large number of genes.phyB-PIF4 module regulates a variety of biological and developmental processes in plants.In this study,we demonstrate that B-BOX PROTEIN 11(BBX11)physically interacts with both phyB and PIF4.BBX11 negatively regulates PIF4 accumulation as well as its biochemical activity,consequently leading to the repression of PIF4-controlled genes’expression and promotion of photomorphogenesis in the prolonged red light.This study reveals a regulatory mechanism that mediates red light signal transduction and sheds a light on phyB-PIF4 module in promoting red light-dependent photomorphognenesis.
基金supported by the National Natural Science Foundation of China(Grant Nos 32100199,31900210,and 31970258)the Peking-Tsinghua Center for Life Sciences(to X.W.D)+4 种基金the Southern University of Science and Technology(to X.W.D)the Jiangsu Natural Science Foundation for Distinguished Young Scholars(Grant No.BK20211525)the Jiangsu"Innovativeand Entrepreneurial Talent"program(to D.X.)the Nanjing Agricultural University(start-up funding to D.X.)the Jiangsu Collaborative Innovation Center for Modern Crop Production(to D.X.).
文摘Light signaling precisely controls photomorphogenic development in plants.PHYTOCHROME INTERACTING FACTOR 4 and 5(PIF4 and PIF5)play critical roles in the regulation of this developmental process.In this study,we report CONSTITUTIVELY PHOTOMORPHOGENIC 1 SUPPRESSOR 6(CSU6)functions as a key regulator of light signaling.Loss of CSU6 function largely rescues the cop1-6 constitutively photomorphogenic phenotype.CSU6 promotes hypocotyl growth in the dark,but inhibits hypocotyl elongation in the light.CSU6 not only associates with the promoter regions of PIF4 and PIF5 to inhibit their expression in the morning,but also directly interacts with both PIF4 and PIF5 to repress their transcriptional activation activity.CSU6 negatively controls a group of PIF4-and PIF5-regulated gene expressions.Mutations in PIF4 and/or PIF5 are epistatic to the loss of CSU6,suggesting that CSU6 acts upstream of PIF4 and PIF5.Taken together,CSU6 promotes light-inhibited hypocotyl elongation by negatively regulating PIF4 and PIF5 transcription and biochemical activity.
基金supported by grants from National Natural Science Foundation of China(31670288)the Talent Support Program of Henan Agricultural University(to H.Z)。
文摘Arabidopsis CONSTITUTIVELY PHOTOMORPHO GENIC1(COP1)and PHYTOCHROME INTERACTING FACTORs(PIFs)are negative regulators,and ELONGATED HYPOCOTYL5(HY5)is a positive regulator of seedling photomorphogenic development.Here,we report that SICKLE(SIC),a proline rich protein,acts as a novel negative regulator of photomorphogenesis.HY5 directly binds the SIC promoter and activates SIC expression in response to light.In turn,SIC physically interacts with HY5 and interferes with its transcriptional regulation of downstream target genes.Moreover,SIC interacts with PIF4 and promotes PIF4-activated transcription of itself.Interestingly,SIC is targeted by COP1 for 26S proteasomemediated degradation in the dark.Collectively,our data demonstrate that light-induced SIC functions as a brake to prevent exaggerated light response via mediating HY5 and PIF4 signaling,and its degradation by COP1 in the dark avoid too strong inhibition on photomorphogenesis at the beginning of light exposure.
基金This work was supported by Shandong Agricultural University,China,SDA-2014.
文摘WRKY transcription factors are known mostly for their function in plant defense,abiotic stress responses,senescence,seed germination,and development of the pollen,embryo,and seed.Here,we report the regulatory functions of two WRKY proteins in photomorphogenesis and PIF4 expression.PIF4 is a critical signaling hub in light,temperature,and hormonal signaling pathways.Either its expression or its accumulation peaks in the morning and afternoon.WRKY2 and WRKY10 form heterodimers and recognize their target site in the PIF4 promoter near the MYB element that is bound by CCA1 and LHY under red and blue light.WRKY2 and WRKY10 interact directly with CCA1/LHY to enhance their targeting but interact indirectly with SHB1.The two WRKY proteins also interact with phyB,and their interaction enhances the targeting of CCA1 and LHY to the PIF4 promoter.SHB1 associates with theWRKY2 andWRKY10 loci and enhances their expression in parallel with the PIF4 expression peaks.This forward regulatory loop further sustains the accumulation of the two WRKY proteins and the targeting of CCA1/LHY to the PIF4 locus.In summary,interactions of two WRKY proteins with CCA1/LHY and phyB maintain an optimal expression level of PIF4 toward noon and afternoon,which is essential to sketch the circadian pattern of PIF4 expression.
基金This work was supported by the National Natural Science Foundation of China(31970256)the Fok Ying Tong Education Foundation(161023)+1 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2019-kb05)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘High temperature activates the transcription factor PHYTOCHROME-INTERACTING FACTOR4(PIF4)to stimulate auxin signaling,which causes hypocotyl elongation and leaf hyponasty(thermomorphogenesis).HOOKLESS1(HLS1)is a recently reported positive regulator of thermomorphogenesis,but the molecular mechanisms by which HLS1 regulates thermomorphogenesis remain unknown.In this study,we initially compared PIF4-and/or HLS1-dependent differential gene expression(DEG)upon high-temperature treatment.We found that a large number of genes are coregulated by PIF4 and HLS1,especially genes involved in plant growth or defense responses.Moreover,we found that HLS1 interacts with PIF4 to form a regulatory module and that,among the HLS1-PIF4-coregulated genes,27.7%are direct targets of PIF4.We also identified 870 differentially alternatively spliced genes(DASGs)in wild-type plants under high temperature.Interestingly,more than half of these DASG events(52.4%)are dependent on both HLS1 and PIF4,and the spliceosome-defective mutant plantsexhibit a hyposensitive response to high temperature,indicating that DASGs are required for thermomorphogenesis.Further comparative analyses showed that the HLS1/PIF4-coregulated DEGs and DASGs exhibit almost no overlap,suggesting that high temperature triggers two distinct strategies to control plant responses and thermomorphogenesis.Taken together,these results demonstrate that the HLS1-PIF4 module precisely controls both transcriptional and posttranscriptional regulation during plant thermomorphogenesis.
文摘(Molecular Plant 11(7):928-942;July 2018;https://doi.Org/10.1016/j.molp.2018.04.005)In the Abstract of this article,there is an error in the sentence"SEU associates with the regulatory regions of INDOLE-3-ACETIC ACID INDUCIBLE6(IAA6)and IAA19 in a PIF4-independent manner,whereas the binding of PIF4 to these genes requires SEU.Furthermore.