汞对小麦幼苗生长和过氧化物酶同工酶的影响

过氧化物酶对植物的生长发育起着重要作用,对不良环境条件的反应也十分敏感。不少学者研究了不良因素对植物过氧化物酶活性及其同工酶谱的影响,证明在逆境条件下过氧化物酶活性常常增强,同工酶谱发生变化;但也有人认为没有影响。在汞作用下,小麦植株体内发生了一系列生理生化变化,但未见汞对小麦幼苗过氧化物酶同工酶影响的系统报道。     

汞对蔬菜幼苗生长及氧化酶同工酶的影响

汞是城市污水中的一种主要有毒物,郊区农民常用这种污水灌溉农作物,造成减产。含汞工业污水对水稻、小麦种子萌发、幼苗及胚根生长的毒性影响及体内某些酶的变化已有一些报道,但对蔬菜幼苗期形态变化与体内某些酶变化的关系则很少有人探讨。我们用不同浓度汞溶液处理番茄等6种作物种子,探讨其对幼苗生长的影响及体内氧化酶同工酶变化的关系,为生产上早期检测作物受汞害的程度、选择抗汞害的作物品种提供依据。     

SO2对作物幼苗超氧化物歧化酶同工酶的影响

SO_2伤害小麦,绿豆,豇豆、四季豆、南瓜,丝瓜幼苗后,引起超氧化物歧化酶(SOD)和过氧化物酶(POD)同工酶谱出现新酶谱带,而且随着污染次数增加,此新同工酶谱带越明显,说明SOD同工酶的变化与SO_2伤害有一定关系,经分析新出现的酶谱带属Cu-Zn-SOD类型。     

Cd胁迫对桐花树同工酶的影响

利用聚丙烯酰胺凝胶垂直板电泳方法,研究了不同浓度Cd胁迫对桐花树幼苗叶片过氧物酶(POD)、超氧化物歧化酶(SOD)、酯酶(EST)同工酶酶谱的影响.结果表明:Cd胁迫下POD和EST同工酶组成发生了较大的变化,酶带颜色深浅和条数均有变化.部分同工酶基因表达在镉胁迫下完全关闭而酶带消失,另一部分同工酶基因表达则被启动而有新的酶带产生.而SOD同工酶酶带的亮度强弱也有明显的变化.这说明桐花树体内POD,EST和SOD同工酶确实能够适应Cd胁迫而产生相应变化,从而调节细胞代谢,以抵抗逆境胁迫.     

染料浓度和盐度对白腐真菌同工酶的电泳分析

应用聚丙烯酰胺凝胶电泳技术分析,并比较了染料废水的两大因子(染料浓度和盐度)对黄孢原毛平革菌过氧化物同工酶谱带的影响程度,结果表明:在染料或盐胁迫下,黄孢原毛平革菌均表现出应急产酶的响应,虽然过氧化物同工酶谱带数量未发生增加或减少,但谱带强度受到较大影响,活性艳红X-3B浓度≤200mg/L或NaCl浓度≤15g/L时均能诱导过量产酶,继续提高染料浓度或盐度将导致产酶抑制,染料浓度对酶带的影响作用高于盐度。     

镉对作物种子萌发、幼苗生长及氧化酶同工酶的影响

本文研究了镉对四种作物的某些影响.玉米和西葫幼苗生长受镉抑制明显,根内POD同工酶谱带比对照减少.旱萝卜幼苗生长虽也受抑,但根内POD没有变化.沙窝青萝卜和西葫幼苗根内COD同工酶谱带也比对照减少,这似乎也与镉害有关.     

重金属Cd、Cu对小麦(Triticum aestivum)幼苗生理生化过程的影响及其毒性机理研究

对Cd、Cu单因子处理下小麦幼苗叶片和根系的SOD、POD酶活、可溶性蛋白含量以及叶片中叶绿素含量的变化进行了研究.结果表明,Cd、Cu胁迫下,小麦幼苗受到损伤的明显症状之一是叶片叶绿素含量下降;小麦植株叶片POD、SOD酶活能够被诱导而升高;重金属Cd、Cu对小麦幼苗根系的损伤较叶片大;重金属对小麦幼苗的毒害机理之一是抑制了蛋白质的生物合成;重金属引起的各个生化指标随着处理浓度和处理时间的变化远比有机污染物(如豆磺隆)简单.     

水溶性有机物对绿麦隆胁迫下小麦幼苗生物利用性和毒性的影响

研究了在2种来源的DOM（水溶性有机物）和绿麦隆作用下,小麦幼苗在不同培养时间（4和10 d）组织累积量和抗氧化系统的响应,探讨了小麦幼苗在DOM作用下对绿麦隆胁迫的毒性响应影响及机制. 结果表明:在不同的培养期内,绿麦隆均抑制了小麦幼苗的生长,而2种不同来源的DOM均缓解了绿麦隆对植株的毒性. DOM的施加使绿麦隆胁迫下小麦叶和根中的丙二醛（MDA）含量降低,同时绿麦隆诱导的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活力也有所降低,然而过氧化物酶（POD）和谷胱甘肽巯基转移酶（GST）的活性却有一定程度的增高. 使用RT-PCR半定量分析方法对SOD和GST的酶活性变化进行了分析,以确证DOM缓解绿麦隆对小麦幼苗的毒性调节机制.      

汞对水稻幼苗根系酯酶同工酶的影响

在污染环境的众多污染物中,汞是一种存低浓度时毒性就很大的积累性的金属毒物。全世界每年汞产量约为6950—10350吨,仅有20％被回收,其余大部分被排入环境。汞对植物外部形态和一些生理生化指标的影响许多学者已经进行了大量的研究工作。有关汞对水稻根系同工酶的影响尚未见报道。为此,我们设计本试验。在观察不同浓度HgCl_2对水稻幼苗生长影响的同时,采用聚丙烯酰胺凝胶电泳法,研究伤害症状的出现与酯酶同工酶的变化关系,为利用同工酶分析法监测汞污染提供科学依据及方法。     

铅胁迫对小麦幼苗抗氧化酶活性的影响

通过营养液培养实验,研究小麦幼苗在遭受铅胁迫后,地上部及根系抗氧化酶活性的变化.试验表明:小麦幼苗受到铅胁迫后,地上部及根系的超氧化物歧化酶(SOD)活性均显著增加,根系中过氧化氢酶(CAT)的活性也比对照有所增加,但不如SOD酶变化剧烈,表明SOD酶活性是比较敏感的生物指标(biomarker).但是,小麦幼苗地上部及根系的丙二醛(MDA)含量仍均比对照显著升高,表明小麦幼苗的膜系统受到了一定程度的破坏.试验同时还反映出,铅胁迫对小麦幼苗根系的影响远远强于地上部.     

镧在小麦幼苗富集与幼苗营养生长的关系

通过暴露和暴露恢复试验研究低浓度稀土元素镧对小麦幼苗营养生长的影响.结果表明,幼苗暴露于0.5～25mg/L镧溶液,镧抑制幼苗根的伸长,降低茎叶和根系的干重,降低矿质元素Ca、Mg、Zn、Mn的含量;镧的植物富集速度及镧从根系向茎叶迁移速度与镧暴露浓度呈明显的对数关系.去除镧后,幼苗生长加快,生物量及根长增加,矿质元素含量升高,但已富集的镧主要在作物体内再分配,很难排出体外,且随作物的生长而逐步的稀释,但仍影响作物生长.幼苗中镧的富集量与幼苗相对干重呈负线性相关,幼苗根系生长比茎叶更容易受到溶液中镧抑制.     

Effects of arsenic on seed germination and physiological activities in wheat seedlings

The effects of arsenic(As)were investigated on seed germination,root and shoot length and their biomass and some other factors to elucidate the toxicity of As.The results showed low concentrations of As(O-1 mg/kg)stimulated seed germination and the growth of root and shoot,however,these factors all decreased gradually at high concentrations of As(5-20 mg/kg).The contents Of O2-,MDA,soluble protein and peroxidase(POD)activity all increased with increasing As concentrations.Soluble sugar content,ascorbate peroxidase(APX),and superoxide dismutase(SOD)activities decreased at low concentrations of As,and increased at high concentrations of As.While acetylsalicylic acid(ASA)and chlorophyll contents,catalase(CAT)activity displayed increasing trend when the concentrations of As was lower than 1 mg/kg,and then decreasing trend.By polyacrylamide gel electrophoresis(PAGE).As induced the expression of POD isozymes of wheat seedlings.As induced the expression of CAT isozymes but inhibited the expression of SOD isozymes of wheat seedlings at concentrations lower than 1 mg/kg.However,As inhibited the expression of CAT isozymes but induced the expression of SOD isozymes at concentrations higher than 5 mg/kg.The results indicated As could exert harmfulness in the early development stage of wheat at inappropriate concentrations.     

P对小麦Cd和As吸收与转运的影响

为了探究磷（P）对小麦幼苗镉（Cd）和砷（As）吸收转运生理机制的影响,通过水培试验,以百农207为供试材料,研究了Cd和As胁迫条件下,外源供P和缺P处理对小麦幼苗生长、根系形态、光合参数、抗氧化系统、离子含量和根茎转移系数的影响.结果表明,与缺P处理相比,外源P供应显著增加As胁迫下小麦幼苗叶绿素的含量,促进根系的生长发育,提高了生物量,而对Cd胁迫下小麦幼苗的生长影响不显著.外源P供应时显著增加了Cd胁迫条件下根系的P和Cd含量,降低了地上部的P和Cd含量;同时显著提高了As胁迫条件下地上部的P和As含量以及As向地上部的转移系数.因此,供P与否对小麦幼苗Cd和As毒害的影响表现出明显的差异性;As胁迫时,外源供P提高了As向地上部的转运能力以及根系的CAT活性,降低了As对小麦的毒害,从而促进了小麦幼苗生物量的累积;而在Cd胁迫条件下,P与Cd之间表现出一定的协同效应,外源供P在一定程度上加重了Cd对小麦的毒害效应.     

Toxic effects of 1-methyl-3-octylimidazolium bromide on the wheat seedlings

The toxic effects of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) on wheat seedlings were evaluated. Wheat seedlings were cultivated in aqueous solution with [C8mim]Br at di erent concentrations (0, 1, 2, 4, 6, 8 mg/L). The contents of photosynthetic pigment and proline, peroxidation of membrane lipid, and activities of antioxidation enzymes (superoxide dismutase, catalase, peroxidase and ascorbate peroxidase) in leaves were measured on day 7 after treatment with [C8mim]Br. The results showed that [C8mim]Br significantly decreased the contents of photosynthetic pigments, activities of antioxidant enzymes in the wheat leaves and in dry weight of seedlings, while increased the proline content and membrane lipid peroxidation. The results suggested that [C8mim]Br can inhibit photosynthesis and lead to oxidative stress to wheat seedlings.     

二氧化硫对作物游离氨基酸浓度的作用

观察了四种作物接触二氧化硫后游离氨基酸,特别是十种昆虫必需氨基酸含量的变化.二氧化硫引起油菜、大豆和小麦叶片中昆虫必需氨基酸浓度明显增加,非必需氨基酸中,增加或减少趋势不一.玉米没有这种反应.二氧化硫熏气的大豆上叶螨生长繁殖快于对照.讨论了植物中氨基酸浓度的增加和大气污染诱发虫害加剧的关系.     

纳米二氧化钛缓解镉胁迫下小麦幼苗生长及生理变化

研究了水培环境中不同浓度纳米二氧化钛（TiO₂-NPs）（0,25,50,100,200 mg/L）缓解Cd对小麦幼苗造成的生理毒害的作用。结果显示:在水培环境下TiO₂-NPs的施用,缓解了Cd对小麦带来的氧化胁迫,减轻了Cd对小麦的毒害作用,显著提高了小麦生物量、根长及株高,改善了小麦光合作用。中浓度（50,100 mg/L）TiO₂-NPs的使用显著提高了小麦幼苗净光合速率。对于所有浓度TiO₂-NPs的施用,小麦幼苗POD酶活均显著低于Cd处理组;SOD酶活在较低浓度（<200 mg/L）时显著低于Cd处理组。TiO₂-NPs通过减轻Cd氧化胁迫作用,有效缓解了Cd对小麦幼苗的毒害,提高了小麦幼苗的光合作用。     

E ects of arsenic on seed germination and physiological activities of wheat seedlings

The effects of arsenic （As） were investigated on seed germination, root and shoot length and their biomass and some other factors to elucidate the toxicity of As. The results showed low concentrations of As （0-1 mg/kg） stimulated seed germination and the growth of root and shoot, however, these factors all decreased gradually at high concentrations of As （5-20 mg/kg）. The contents of O2^-, MDA, soluble protein and peroxidase （POD） activity all increased with increasing As concentrations. Soluble sugar content, ascorbate peroxidase （APX）, and superoxide dismutase （SOD） activities decreased at low concentrations of As, and increased at high concentrations of As. While acetylsalicylic acid （ASA） and chlorophyll contents, catalase （CAT） activity displayed increasing trend when the concentrations of As was lower than 1 mg/kg, and then decreasing trend. By polyacrylamide gel electrophoresis （PAGE）, As induced the expression of POD isozymes of wheat seedlings. As induced the expression of CAT isozymes but inhibited the expression of SOD isozymes of wheat seedlings at concentrations lower than 1 mg/kg. However, As inhibited the expression of CAT isozymes but induced the expression of SOD isozymes at concentrations higher than 5 mg/kg. The results indicated As could exert harmfulness in the early development stage of wheat at inappropriate concentrations.     

Uptake and accumulation of copper by roots and shoots of maize(Zea may L.)

The effects of different concentrations of copper sulfate on rootand shoot growth of maize(Zea mays L.) and the uptake and accumulation of Cu2+ by its roots and shoots were investigated in the present study. The concentrations of opper sulfate (CuSO4.5H2O) used were in the range of 10-5-10-3mol/L. Root growth decreased progressively with increasing concentration of Cu2+ in solution. The seedlings exposed to 10-3 mol/L Cu exhibited substantial growth reduction, yielding only 68% of the root length of the control. The shoot growth of the seedlings grown at 10-5-10-4 mol/L Cu2+ were more or less than the same as the control seedlings. The leaves treated with 10-3 mol/L Cu2+ were obviously inhibited in shoot growth. The fresh and dry weights both in roots and shots decreased progressively with increasing Cu2+ concentration.This fits well with the above mentioned effects of copper sulfate on root growth. Zea mays has considerable ability to remove Cu from solutions and accumulate it. The Cu content in roots of Z. Mays increased with increasing solution concentration of Cu2+. The amount of Cu in roots of plants treated with 10-3, 10-4 and 10-5 mol/L Cu2+ were 10, 8 and 1.5 fold, respectively, greater than that of roots of control plant. However, the plants transported and concentrated only a small amount of Cu in their shoots.     

脱硫废水添加对煤燃烧时汞析出特性的影响

为探究含氯脱硫废水溶液添加对煤燃烧时汞析出特性的影响,分别利用沉降炉和管式炉实验装置进行了3种煤在1200℃下的燃烧实验。实验时通过改变模拟脱硫废水溶液的添加量来控制燃煤中氯的质量分数分别为0.00%、0.02%、0.04%和0.06%。分析煤燃烧后烟气中汞浓度、吸收液、飞灰和煤灰中汞含量的变化情况发现:随着加氯量的增加,烟气中Hg0浓度逐渐降低,Hg2+浓度则逐渐升高,但对Hgt（气态总汞）浓度的提升效果相对较差。当加氯量为0.06%时,煤种B在沉降炉中燃烧后烟气中Hg0浓度下降约2.3 μg/m3,而Hg2+浓度提高约2.6 μg/m3,但Hgt浓度仅提高了0.3 μg/m3。氯的添加也会使飞灰中汞含量增加,煤灰中汞含量降低。通过综合对比分析沉降炉和管式炉实验结果发现:无论是否添加氯,煤在沉降炉中燃烧后烟气中Hg0比例均小于管式炉实验结果。当煤种B加氯量为0.06%时,在沉降炉和管式炉中燃烧后烟气中Hg0含量占比分别为50.6%和67.8%。此外,还发现3种煤粉在管式炉中加氯燃烧后汞的析出率提高趋势均较沉降炉明显。故含氯脱硫废水溶液的添加可以改变煤燃烧时汞的析出特性,且有利于促进烟气中Hg0的氧化,对燃煤烟气脱汞具有重要作用。