土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响...土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响叶和花发育的重要功能基因。本文以lfr功能缺失突变体为实验材料,观察了不同浓度盐处理下的种子萌发、子叶转绿、主根生长及成苗生长表型,结果表明lfr突变体对盐胁迫敏感;定量RT-PCR检测表明在Na Cl处理下,盐胁迫SOS信号通路中的SOS1在lfr中的受诱导程度显著低于野生型,这与lfr突变体盐敏感表型相吻合,可能是导致lfr突变体对盐胁迫敏感的诱因之一。上述结果预示着LFR可能通过调控SOS1基因的转录表达,参与植物对盐胁迫的响应。展开更多
In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed...In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed by University of Science and Technology of China. The flow blockage shall cause a degradation of the heat transfer between the fuel assembly and the coolant potentially,which can eventually result in the clad fusion. An analysis of core blockage accidents in a single assembly is of great significance for LFR. Such scenarios are investigated by using the best estimation code RELAP5. Reactivity feedback and axial power profile are considered. The crosssectional fraction of blockage, axial position of blockage,and blockage-developing time are discussed. The cladding material failure shall be the biggest challenge and shall be a considerable threat for integrity of the fuel assembly if the cross-sectional fraction of blockage is over 94%. The blockage-developing time only affects the accident progress. The consequence will be more serious if the axial position of a sudden blockage is closer to the core outlet.The method of analysis procedure can also be applied to analyze similar transient behaviors of other fuel-type reactors.展开更多
染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征...染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征尚有待进一步探究.酵母单杂交实验表明,酵母转录因子GAL4的DNA结合域与全长LFR的融合蛋白(GBD-LFR)具有转录辅激活活性,LFR的C端至少有2个犰狳蛋白(ARM)重复结构域及完整N端对于其转录辅激活活性是必需的.但在野生型拟南芥原生质体中,与典型的转录激活因子相比,GBD-LFR的转录辅激活活性并不明显.缺失或突变LFR与黄色荧光蛋白(YFP)的原生质体亚细胞定位的荧光显微观察表明,N端的1～25位氨基酸,特别是其中第22位的赖氨酸和第4、23以及25位精氨酸影响其核定位.利用激光共聚焦显微镜观察共表达黄色或青色荧光(CFP)融合蛋白的细胞核内分布,结果表明LFR与染色质结构蛋白组蛋白H4及染色质结合蛋白HMGA有一定的核内共定位.这些结果表明LFR可能作为一个染色质相关的蛋白质,在拟南芥的生长发育中发挥重要作用.展开更多
文摘土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响叶和花发育的重要功能基因。本文以lfr功能缺失突变体为实验材料,观察了不同浓度盐处理下的种子萌发、子叶转绿、主根生长及成苗生长表型,结果表明lfr突变体对盐胁迫敏感;定量RT-PCR检测表明在Na Cl处理下,盐胁迫SOS信号通路中的SOS1在lfr中的受诱导程度显著低于野生型,这与lfr突变体盐敏感表型相吻合,可能是导致lfr突变体对盐胁迫敏感的诱因之一。上述结果预示着LFR可能通过调控SOS1基因的转录表达,参与植物对盐胁迫的响应。
文摘In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed by University of Science and Technology of China. The flow blockage shall cause a degradation of the heat transfer between the fuel assembly and the coolant potentially,which can eventually result in the clad fusion. An analysis of core blockage accidents in a single assembly is of great significance for LFR. Such scenarios are investigated by using the best estimation code RELAP5. Reactivity feedback and axial power profile are considered. The crosssectional fraction of blockage, axial position of blockage,and blockage-developing time are discussed. The cladding material failure shall be the biggest challenge and shall be a considerable threat for integrity of the fuel assembly if the cross-sectional fraction of blockage is over 94%. The blockage-developing time only affects the accident progress. The consequence will be more serious if the axial position of a sudden blockage is closer to the core outlet.The method of analysis procedure can also be applied to analyze similar transient behaviors of other fuel-type reactors.
文摘染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征尚有待进一步探究.酵母单杂交实验表明,酵母转录因子GAL4的DNA结合域与全长LFR的融合蛋白(GBD-LFR)具有转录辅激活活性,LFR的C端至少有2个犰狳蛋白(ARM)重复结构域及完整N端对于其转录辅激活活性是必需的.但在野生型拟南芥原生质体中,与典型的转录激活因子相比,GBD-LFR的转录辅激活活性并不明显.缺失或突变LFR与黄色荧光蛋白(YFP)的原生质体亚细胞定位的荧光显微观察表明,N端的1～25位氨基酸,特别是其中第22位的赖氨酸和第4、23以及25位精氨酸影响其核定位.利用激光共聚焦显微镜观察共表达黄色或青色荧光(CFP)融合蛋白的细胞核内分布,结果表明LFR与染色质结构蛋白组蛋白H4及染色质结合蛋白HMGA有一定的核内共定位.这些结果表明LFR可能作为一个染色质相关的蛋白质,在拟南芥的生长发育中发挥重要作用.
