Soil salinity is a serious environmental threat to plant growth and flowering.Flowering in the right place,at the right time,ensures maximal reproductive success for plants.Salinity-delayed flowering is considered a s...Soil salinity is a serious environmental threat to plant growth and flowering.Flowering in the right place,at the right time,ensures maximal reproductive success for plants.Salinity-delayed flowering is considered a stress coping/survival strategy and the molecular mechanisms underlying this process require further studies to enhance the crop's salt tolerance ability.A nuclear pore complex(NPC)component,HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1(HOS1),has been recognized as a negative regulator of plant cold responses and flowering.Here,we challenged the role of HOS1 in regulating flowering in response to salinity stress.Interestingly,we discovered that HOS1 can directly interact with and ubiquitinate transcription factor SPL9(SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9)to promote its protein degradation in response to salinity stress.Moreover,we demonstrated that HOS1 and SPL9 antagonistically regulate plant flowering under both normal and salt stress conditions.HOS1 was further shown to negatively regulate the expression of SPLs and several key flowering genes in response to salinity stress.These results jointly revealed that HOS1 is an important integrator in the process of modulating salinity-delayed flowering,thus offering new perspectives on a salinity stress coping strategy of plants.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
Nuclear pore complexes(NPCs),which comprise multiple copies of nucleoporins(Nups),are large protein assemblies embedded in the nuclear envelope connecting the nucleus and cytoplasm.Although it has been known that Nups...Nuclear pore complexes(NPCs),which comprise multiple copies of nucleoporins(Nups),are large protein assemblies embedded in the nuclear envelope connecting the nucleus and cytoplasm.Although it has been known that Nups affect flowering in Arabidopsis,the underlying mechanisms are poorly understood.Here,we show that loss of function of Nucleoporin 160(Nup160)leads to increased abundance of CONSTANS(CO)protein and the resulting upregulation of FLOWERING LOCUS T(FT)specifically in the morning.We demonstrate that Nup160 regulates CO protein stability through affecting NPC localization of an E3-ubiquitin ligase,HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1(HOS1),which destabilizes CO protein in the morning period.Taken together,these results provide a mechanistic understanding of Nup function in the transition from vegetative to reproductive growth,suggesting that deposition of HOS1 at NPCs by Nup160 is essential for preventing precocious flowering in response to photoperiod in Arabidopsis.展开更多
目的构建HO1基因的真核干扰表达载体,评估其转染人胃癌细胞系SGC-7901细胞后对HO1基因的干扰效果及其功能。方法将外源性重组真核干扰表达载体HO1基因(pS/HO1)转染到人胃癌细胞系SGC-7901内,经G418筛选并建立siRNA表达载体稳定沉默胃癌S...目的构建HO1基因的真核干扰表达载体,评估其转染人胃癌细胞系SGC-7901细胞后对HO1基因的干扰效果及其功能。方法将外源性重组真核干扰表达载体HO1基因(pS/HO1)转染到人胃癌细胞系SGC-7901内,经G418筛选并建立siRNA表达载体稳定沉默胃癌SGC-7901细胞HO1基因的细胞系,分为SGC-7901-pS/HO1组,转染空质粒细胞(SGC-7901-pS)组和未处理细胞(SGC-7901)组;用实时荧光定量PCR和蛋白印迹验证HO1基因在各组细胞中的表达,并通过CCK-8和克隆形成实验分别观察HO1基因被干扰后细胞的生物学行为。结果与SGC-7901-pS组相比,SGC-7901-pS/HO1细胞中HO1基因蛋白表达明显减少,降低了5.58倍(0.321±0.051 vs 1.675±0.153,P<0.05);与对照组相比较,SGC-7901-pS/HO1实验组较SGC-7901-pS对照组细胞增殖数量明显减少(P<0.001);与转染pS空载体的SGC-7901-pS细胞对照组相比,SGC-7901-pS/HO1细胞的克隆形成明显减少,降低了3.45倍(8.32±1.142 vs 2.32±0.362,P<0.05)。结论 HO1基因真核siRNA表达载体筛选成功,为继续深入的研究HO1基因在胃癌中的功能提供了依据。展开更多
基金supported by the National Natural Science Foundation of China(NSFC)32350610245,32150410345,32070307 and 32270308Scientific and Technological Innovation Talents in Colleges and Universities in Henan,China(23HASTIT036).
文摘Soil salinity is a serious environmental threat to plant growth and flowering.Flowering in the right place,at the right time,ensures maximal reproductive success for plants.Salinity-delayed flowering is considered a stress coping/survival strategy and the molecular mechanisms underlying this process require further studies to enhance the crop's salt tolerance ability.A nuclear pore complex(NPC)component,HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1(HOS1),has been recognized as a negative regulator of plant cold responses and flowering.Here,we challenged the role of HOS1 in regulating flowering in response to salinity stress.Interestingly,we discovered that HOS1 can directly interact with and ubiquitinate transcription factor SPL9(SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9)to promote its protein degradation in response to salinity stress.Moreover,we demonstrated that HOS1 and SPL9 antagonistically regulate plant flowering under both normal and salt stress conditions.HOS1 was further shown to negatively regulate the expression of SPLs and several key flowering genes in response to salinity stress.These results jointly revealed that HOS1 is an important integrator in the process of modulating salinity-delayed flowering,thus offering new perspectives on a salinity stress coping strategy of plants.
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This work was supported by the Singapore National Research Foundation Investigatorship Program(NRF-NRFI2016-02)the intramural research support from National University of Singapore and Temasek Life Sciences Laboratory.
文摘Nuclear pore complexes(NPCs),which comprise multiple copies of nucleoporins(Nups),are large protein assemblies embedded in the nuclear envelope connecting the nucleus and cytoplasm.Although it has been known that Nups affect flowering in Arabidopsis,the underlying mechanisms are poorly understood.Here,we show that loss of function of Nucleoporin 160(Nup160)leads to increased abundance of CONSTANS(CO)protein and the resulting upregulation of FLOWERING LOCUS T(FT)specifically in the morning.We demonstrate that Nup160 regulates CO protein stability through affecting NPC localization of an E3-ubiquitin ligase,HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1(HOS1),which destabilizes CO protein in the morning period.Taken together,these results provide a mechanistic understanding of Nup function in the transition from vegetative to reproductive growth,suggesting that deposition of HOS1 at NPCs by Nup160 is essential for preventing precocious flowering in response to photoperiod in Arabidopsis.
文摘目的构建HO1基因的真核干扰表达载体,评估其转染人胃癌细胞系SGC-7901细胞后对HO1基因的干扰效果及其功能。方法将外源性重组真核干扰表达载体HO1基因(pS/HO1)转染到人胃癌细胞系SGC-7901内,经G418筛选并建立siRNA表达载体稳定沉默胃癌SGC-7901细胞HO1基因的细胞系,分为SGC-7901-pS/HO1组,转染空质粒细胞(SGC-7901-pS)组和未处理细胞(SGC-7901)组;用实时荧光定量PCR和蛋白印迹验证HO1基因在各组细胞中的表达,并通过CCK-8和克隆形成实验分别观察HO1基因被干扰后细胞的生物学行为。结果与SGC-7901-pS组相比,SGC-7901-pS/HO1细胞中HO1基因蛋白表达明显减少,降低了5.58倍(0.321±0.051 vs 1.675±0.153,P<0.05);与对照组相比较,SGC-7901-pS/HO1实验组较SGC-7901-pS对照组细胞增殖数量明显减少(P<0.001);与转染pS空载体的SGC-7901-pS细胞对照组相比,SGC-7901-pS/HO1细胞的克隆形成明显减少,降低了3.45倍(8.32±1.142 vs 2.32±0.362,P<0.05)。结论 HO1基因真核siRNA表达载体筛选成功,为继续深入的研究HO1基因在胃癌中的功能提供了依据。
