Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the ex...Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the expression of multiple senescence-related genes and physiological phenotypes were monitored in WRKY10-and VQ MOTIF-CONTAINING PROTEIN8(VQ8)-overexpressing plants and the wrky10 and vq8 mutants.Our results showed that WRKY10 positively regulates abscisic acid(ABA)-and dark-induced senescence(DIS)by directly regulating the expression of multiple senescence-related genes.The VQ8 protein,a repressor of WRKY10,negatively regulates WRKY10-mediated DIS.The WRKY10-VQ8 module fine-tunes the progression of DIS.ABA,methyl jasmonate,and H_(2)O_(2) accelerate WRKY10-mediated DIS,whereas ammonium nitrate and dithiothreitol delay WRKY10-mediated DIS.Further analysis revealed that WRKY10 and VQ8 interact with ABA RESPONSIVE ELEMENT BINDING FACTOR1(ABF1)or ABF2.VQ8 represses the transcriptional activity of ABF1 and ABF2.Overexpression of ABF1 or ABF2 accelerates ABA-and dark-induced senescence and H_(2)O_(2) accumulation in N.benthamiana leaves,and WRKY10 and VQ8 can inhibit either ABF1-or ABF2-induced cell necrosis.Taken together,WRKY10 integrates multiple senescence signals to establish an orderly progression of leaf senescence.The VQ8 protein acts as a brake on WRKY10-induced senescence and ABF1/2-induced cell death,preventing uncontrolled cell death.展开更多
Recent studies in Arabidopsis have revealed that some vq motif-containing proteins physically interact with WRKY transcription factors; however, their specific biological functions are still poorly understood. In this...Recent studies in Arabidopsis have revealed that some vq motif-containing proteins physically interact with WRKY transcription factors; however, their specific biological functions are still poorly understood. In this study, we confirmed the interaction between VQ1o and WRKY8, and show that VQ1o and WRKY8 formed a complex in the plant cell nucleus. Yeast two-hybrid analysis showed that the middle region of WRKY8 and the vq motif of vqlo are critical for their interaction, and that this interaction promotes the DNA-binding activity of WRKY8. Further investigation revealed that the VqlO protein was exclusively localized in the nucleus, and VQ1o was predominantly expressed in siliques, vQ1o expression was strongly responsive to the necrotrophic fungal pathogen, Botrytis cinerea and defense-relatedhormones. Phenotypic analysis showed that disruption of VQlo increased mutant plants susceptibility to the fungal pathogen B. cinerea, whereas constitutive-expres- sion of VQlo enhanced resistance to B. cinerea. Consis- tent with these findings, expression of the defenserelated PLANT DEFENSIN1.2 （PDFt2） gene was decreased in vqlo mutant plants, after B. cinerea infection, but increased in vQ1o-overexpressing transgenic plants. Taken together, our findings provide evidence that VQlo physically interacts with WRKY8 and positively regulates plant basal resistance against the necrotrophic fungal pathogen B. cinerea.展开更多
Light-emitting diode(LED)-based visible light communication(VLC) has become a potential candidate for nextgeneration ultra-high-speed indoor wireless communication. In this paper, four special-shaped 8-quadrature ampl...Light-emitting diode(LED)-based visible light communication(VLC) has become a potential candidate for nextgeneration ultra-high-speed indoor wireless communication. In this paper, four special-shaped 8-quadrature amplitude modulation(QAM) constellations are investigated in a single-carrier VLC system. It is numerically verified and experimentally demonstrated that circular(7,1) shows obvious superiority in the performance of the dynamic range of signal voltage peak-to-peak(vpp) value and bit error rate(BER). Next best is rectangular, followed by triangular; circular(4,4) has the worst performance. A data rate of 1.515 Gbit/s is successfully achieved by circular(7,1) employing a red chip LED over 0.5 m indoor free space transmission below a BER threshold of3.8 × 10^(-3). Compared with circular(4,4), the traditional 8-QAM constellation, circular(7,1) provides a wider dynamic range of signal vpp, a higher data rate, and a longer transmission distance. To the best of our knowledge,this is the first investigation into the performance differences of special-shaped 8-QAM constellations in a highspeed, single-carrier VLC system, and the results comprehensively demonstrate that circular(7,1) is the optimal option.展开更多
Mediator is a highly conserved large protein complex(25 proteins,>1000 kD a)and preeminently responsible for eu-karyotic transcription,which contains a dissociable‘Cdk8 module’.Although increasing evidence demons...Mediator is a highly conserved large protein complex(25 proteins,>1000 kD a)and preeminently responsible for eu-karyotic transcription,which contains a dissociable‘Cdk8 module’.Although increasing evidence demonstrates that Cdk8 module plays both positive and negative roles in transcription regulation,the detailed structure,and subu-nit organization,molecular mechanism how it regulates transcription remain elusive.Here we used single-particle electron microscopy to characterize the structure and subunit organization of the Cdk8 module and illuminated the substantial mobility of the Med13 subunit results in the structural fl exibility.The Cdk8 module interaction with core Mediator is concurrent with active transcription in vivo.An interaction with the Cdk8 module induces core Mediator into very extended conformation in vitro,which is presumed to be an active functional state of Mediator.Taken together,our results illuminated the detailed archi-tecture of Cdk8 module,and suggested the Cdk8 module could positively regulate transcription by modulating Me-diator conformation.展开更多
1教学背景本课来自外研社新标准英语四年级下册第八模块第一单元Module 8 Unit 1 He lives in the east of the US.通过本节课的学习,使得学生们在今后的学习和生活中能运用英语来描述其城市的地理位置。2教材分析本模块的主演内容是说...1教学背景本课来自外研社新标准英语四年级下册第八模块第一单元Module 8 Unit 1 He lives in the east of the US.通过本节课的学习,使得学生们在今后的学习和生活中能运用英语来描述其城市的地理位置。2教材分析本模块的主演内容是说明方位,谈论中国和美国的城市。Unit 1的课文情境是Daming向Sam介绍美国。Daming说他的表哥Simon住在美国东部。Sam问是不是住在洛杉矶。展开更多
基金supported by the National Natural Science Foundation of China (31371557 and 31571574)Wenzhou Basic Scientific Research Project (N20240009)。
文摘Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the expression of multiple senescence-related genes and physiological phenotypes were monitored in WRKY10-and VQ MOTIF-CONTAINING PROTEIN8(VQ8)-overexpressing plants and the wrky10 and vq8 mutants.Our results showed that WRKY10 positively regulates abscisic acid(ABA)-and dark-induced senescence(DIS)by directly regulating the expression of multiple senescence-related genes.The VQ8 protein,a repressor of WRKY10,negatively regulates WRKY10-mediated DIS.The WRKY10-VQ8 module fine-tunes the progression of DIS.ABA,methyl jasmonate,and H_(2)O_(2) accelerate WRKY10-mediated DIS,whereas ammonium nitrate and dithiothreitol delay WRKY10-mediated DIS.Further analysis revealed that WRKY10 and VQ8 interact with ABA RESPONSIVE ELEMENT BINDING FACTOR1(ABF1)or ABF2.VQ8 represses the transcriptional activity of ABF1 and ABF2.Overexpression of ABF1 or ABF2 accelerates ABA-and dark-induced senescence and H_(2)O_(2) accumulation in N.benthamiana leaves,and WRKY10 and VQ8 can inhibit either ABF1-or ABF2-induced cell necrosis.Taken together,WRKY10 integrates multiple senescence signals to establish an orderly progression of leaf senescence.The VQ8 protein acts as a brake on WRKY10-induced senescence and ABF1/2-induced cell death,preventing uncontrolled cell death.
基金supported by the National Natural Science Foundation of China(31671274,91417307)the Innovative Team of Yunnan Province(2014HC017)
文摘Recent studies in Arabidopsis have revealed that some vq motif-containing proteins physically interact with WRKY transcription factors; however, their specific biological functions are still poorly understood. In this study, we confirmed the interaction between VQ1o and WRKY8, and show that VQ1o and WRKY8 formed a complex in the plant cell nucleus. Yeast two-hybrid analysis showed that the middle region of WRKY8 and the vq motif of vqlo are critical for their interaction, and that this interaction promotes the DNA-binding activity of WRKY8. Further investigation revealed that the VqlO protein was exclusively localized in the nucleus, and VQ1o was predominantly expressed in siliques, vQ1o expression was strongly responsive to the necrotrophic fungal pathogen, Botrytis cinerea and defense-relatedhormones. Phenotypic analysis showed that disruption of VQlo increased mutant plants susceptibility to the fungal pathogen B. cinerea, whereas constitutive-expres- sion of VQlo enhanced resistance to B. cinerea. Consis- tent with these findings, expression of the defenserelated PLANT DEFENSIN1.2 （PDFt2） gene was decreased in vqlo mutant plants, after B. cinerea infection, but increased in vQ1o-overexpressing transgenic plants. Taken together, our findings provide evidence that VQlo physically interacts with WRKY8 and positively regulates plant basal resistance against the necrotrophic fungal pathogen B. cinerea.
基金National Natural Science Foundation of China(NSFC)(61571133)National"863"Program of China(2015AA016904)
文摘Light-emitting diode(LED)-based visible light communication(VLC) has become a potential candidate for nextgeneration ultra-high-speed indoor wireless communication. In this paper, four special-shaped 8-quadrature amplitude modulation(QAM) constellations are investigated in a single-carrier VLC system. It is numerically verified and experimentally demonstrated that circular(7,1) shows obvious superiority in the performance of the dynamic range of signal voltage peak-to-peak(vpp) value and bit error rate(BER). Next best is rectangular, followed by triangular; circular(4,4) has the worst performance. A data rate of 1.515 Gbit/s is successfully achieved by circular(7,1) employing a red chip LED over 0.5 m indoor free space transmission below a BER threshold of3.8 × 10^(-3). Compared with circular(4,4), the traditional 8-QAM constellation, circular(7,1) provides a wider dynamic range of signal vpp, a higher data rate, and a longer transmission distance. To the best of our knowledge,this is the first investigation into the performance differences of special-shaped 8-QAM constellations in a highspeed, single-carrier VLC system, and the results comprehensively demonstrate that circular(7,1) is the optimal option.
基金This work was supported by grants from the National Basic Research Program(973 Program)(No.2013CB910200)the National Natural Science Foundation of China(Grant Nos.31170694 and 31222017)+1 种基金Ministry of Education of PRC(NCET-11-0874)Chinese Academy Of Sciences(48500108-6).
文摘Mediator is a highly conserved large protein complex(25 proteins,>1000 kD a)and preeminently responsible for eu-karyotic transcription,which contains a dissociable‘Cdk8 module’.Although increasing evidence demonstrates that Cdk8 module plays both positive and negative roles in transcription regulation,the detailed structure,and subu-nit organization,molecular mechanism how it regulates transcription remain elusive.Here we used single-particle electron microscopy to characterize the structure and subunit organization of the Cdk8 module and illuminated the substantial mobility of the Med13 subunit results in the structural fl exibility.The Cdk8 module interaction with core Mediator is concurrent with active transcription in vivo.An interaction with the Cdk8 module induces core Mediator into very extended conformation in vitro,which is presumed to be an active functional state of Mediator.Taken together,our results illuminated the detailed archi-tecture of Cdk8 module,and suggested the Cdk8 module could positively regulate transcription by modulating Me-diator conformation.
文摘1教学背景本课来自外研社新标准英语四年级下册第八模块第一单元Module 8 Unit 1 He lives in the east of the US.通过本节课的学习,使得学生们在今后的学习和生活中能运用英语来描述其城市的地理位置。2教材分析本模块的主演内容是说明方位,谈论中国和美国的城市。Unit 1的课文情境是Daming向Sam介绍美国。Daming说他的表哥Simon住在美国东部。Sam问是不是住在洛杉矶。
