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1.
增强UV-B辐射对小麦叶中CAT、POX和SOD活性的影响   总被引:11,自引:2,他引:9  
研究了0(CK),8.82kJ/m^2(T1)及12.6kJ/m^2(T2)三种剂量的紫外线B(UV-B,280~320nm)辐射对温室种植的小麦膜伤害的机理,试验结果表明,在增强UV-B辐射下,与对照相比,膜脂过氧化物产-丙二醛(MDA)含量明显升高,同时膜脂脂肪酸组成配比改变,不饱和度指数(IUFA)有所下降,并具剂量效应,过氧化氢酶(CAT),过氧化物酶(POX)活性显著升高,而超氧歧化酶(  相似文献   

2.
UV—B辐射对小麦叶片H2O2代谢的影响   总被引:12,自引:1,他引:11  
研究了温室种植的小麦在0(CK)、8.82kJ/m^2(T1)和12.6kJ/m^2(T2)三种剂量的紫外线B(UV-B)辐射下H2O2含量的变化及其机理。UV-B辐射下H2O2、还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量增加,抗坏血酸过氧化物酶(APx)和谷胱甘肽不原酶(GR)活性升高,脂肪酸不饱和度指数(IUFA)降低。SDS-PAGE谱图没有质上的差异,但凝胶着色深浅有变化。分析  相似文献   

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增强UV—B辐射对蚕豆叶片微粒体膜一些性质的影响   总被引:11,自引:0,他引:11  
温室条件下,用0,8.65kJm^-2d^-1及11.2kJm^-2d^-1不同剂量的UV-B辐射处理蚕豆幼苗。Ca^2+-ATPase及Mg^2+-ATPase的活性在辐射处理期间下降。在处理21d,T1和T2微粒体膜的MDA含量明显高于对照,同时IUFA急剧下降,且呈明显的剂量效应。  相似文献   

4.
UV—B及红光对大棚番茄品质的影响   总被引:30,自引:4,他引:26  
冬季蓝色无谪膜塑料大棚内有效光合辐射(PAR)和紫外B(UV-B)都比棚外低,给大棚番茄补充照射UV-B和红光。结果表明,红光可提高番茄果实糖、酸含量。高剂量UV-B(0.95kj.m^-1.d^-1,0.71kj.m^-2.d^-1)降低番茄红素C(Vc)的含量,低剂量UV0-B(0.54kj.m^-1.d^-1,0.65kj.m^-2.d^-1)可提高番茄红素和Vc含量。低剂量kj.m^-2.  相似文献   

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紫外光B辐射增强对水稻叶片内IAA和ABA含量的影响   总被引:9,自引:0,他引:9  
两个水稻品种CK46和Dular生长在人工气候箱的条件下,在0.0和13.0kJm^-2day^-1下进行4周的照射处理,研究UV-8对水稻体内内源IAA和ABA含量的影响。结果表明:随着UV-B处理时间的延长,CK46和Dular叶片内的IAA含量下降。相反,UV-B辐射增强使两个品种叶片内的ABA含量上升。  相似文献   

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紫外光B辐射对菠菜叶片脂质过氧化作用的影响   总被引:8,自引:0,他引:8  
菠菜(SpinaciaoleraceaMil.)品种“华菠一号”生长在室内条件下,以0.0和13.0kJ·m-2·d-1的UVB进行照射处理,研究了UVB对菠菜叶片内类黄酮和脂质过氧化作用的影响。结果表明:UVB辐射降低了菠菜的单株叶鲜重,诱导了体内吸收UVB的类黄酮化合物的大量积累,并使可溶性蛋白含量与叶绿素含量下降。UVB辐射能使菠菜叶片内O-·2及丙二醛(MDA)含量大幅度上升,而使抗坏血酸(AsA)含量下降。UVB辐射能使菠菜叶片内过氧化物酶(POX)、SOD的活性大幅度上升,而过氧化氢酶(CAT)活性仅略有增加。初步推测:UVB辐射首先诱导菠菜叶片内O-·2的积累,并导致膜脂质过氧化作用,从而抑制菠菜生长。O-·2的积累能诱导抗氧化酶活性的上升,但抗氧化酶活性的上升和吸收UV的类黄酮化合物的积累并不能扭转UVB对菠菜的伤害。  相似文献   

7.
纯化了ArthrobacterD-木糖异构酶的三个突变体,T89S,V134I的比尖(U/mg)分别为3.42和6.18,W136E没有生。T89S和V134I的活性需要二价阳离子,对于T89S,Mg^2^+的作用强于Co^2^+。在以木糖为底物时,T89S的Km值为49.8mmol/L,V134I的Km值为9.8mmol/L,在以果糖为底物时,木糖醇对T89S是竞争性抑制剂,山梨糖醇对T89S和  相似文献   

8.
三丁基锡对人红细胞膜Na^+,K^+—ATPase活性的抑制作用   总被引:1,自引:0,他引:1  
三丁基锡(TBT)是人红细胞膜上Na^+,K^+-ATPase的一种抑制剂。该化合物对Na^+,K^+-ATPase有很强的抑制能力。在正常的反应体系中,TBT浓度仅为10μmol/L时,该酶的活性全部丧失;其抑制Na^+,K^+-ATPase的IC50值为2.2μmol/L.K^+能增强TBT的这种抑制作用,TBT为K^+的反竞争性抑制剂。  相似文献   

9.
增强UV—B辐射对菜豆蛋白质代谢的影响   总被引:18,自引:0,他引:18  
模拟研究了温室条件下兰州地区臭氧层减薄25 % 时增强的UVB(280 ~320 nm) 辐射对菜豆( Phaseolusvulgaris L.) 蛋白质代谢的影响。菜豆幼苗期,UVB辐射(UVBBE:16 kJ·m -2·d-1) 促进菜豆叶片中蛋白质的合成;菜豆生长后期,UVB辐射则抑制蛋白质的合成,降低叶片中可溶性蛋白质的含量,促进蛋白水解酶活性的上升和总游离氨基酸的积累。SDSPAGE分析表明,UVB辐射使幼苗期菜豆叶片中88 kD、76 kD、42 kD、35 kD、33 kD 多肽的含量上升;而在菜豆生长后期,UVB辐射使大分子量多肽(76 kD 以上) 的含量迅速下降,10~14 kD、29 kD、33 kD、35kD的多肽含量上升。蛋白质代谢的这种变化可能是植物的一种适应性反应  相似文献   

10.
机械力对鼠脑微血管内皮细胞膜电流的影响   总被引:1,自引:0,他引:1  
采用膜片钳技术以全细胞方式在鼠脑微血管内皮细胞中记录到一延迟外向电流,对K^+具有高度特异性,胞外施加20mmol/L的TEA-Cl在明显抑制该电流。实验的保持电位定在-100mV,测试电位从-100mV至+90mV,每次增加10mV,刺激波宽为2100ms。该电流具有TEA敏感,并有浓度依赖性,其IC50约为2.0mmol/L,类似延迟整流性钾电流特征(IKv)。机械力作用下可引出一外向电流,膜  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

15.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

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Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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