首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8篇
  免费   1篇
  国内免费   1篇
安全科学   1篇
综合类   2篇
基础理论   3篇
污染及防治   3篇
灾害及防治   1篇
  2018年   1篇
  2012年   2篇
  2011年   1篇
  2009年   1篇
  2005年   2篇
  2004年   1篇
  1999年   1篇
  1995年   1篇
排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
Brassinosteroids (BRs) are involved in the amelioration of various biotic and abiotic stresses. With an aim to explore the role of BRs under heavy metal stress, plants of Brassica juncea L. were grown in pots. The plants were subjected to various concentrations of Nickel metal (0.0, 0.2, 0.4 and 0.6 mM) and harvested on 60th day in order to observe the expression of these hormones. The isolated BRs from the leaves of Brassica plants characterized by GC-MS include 24-Epibrassinolide (24-EBL), Castasterone, Dolicholide and Typhasterole. The effect of isolated 24-EBL was studied on Ni metal uptake and antioxidative defense system in 60 d old plants of Brassica. It was observed that 24-EBL significantly increased the activities of stress ameliorating enzymes and lowered the metal uptake in plants. This is the first report in B. juncea L. plants showing the expression of BRs under metal treatments and effect of the isolated 24-EBL on metal uptake and in oxidative stress management.  相似文献   
2.
SeasonalchangesofendogenousABAandcytokininsinenvironmentaladaptationofdifferentecotypesofreedplantsWangHongliang,ZhangChengli...  相似文献   
3.
Zhang B  Zhang H  Jin J  Ni Y  Chen J 《Chemosphere》2012,88(7):798-805
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are ubiquitous contaminants and can be considerably accumulated by natural plants. In order to elucidate the biochemical and physiological responses of plant to PCDD/Fs, tobacco Bright Yellow-2 (BY-2) cells were selected as model plant and treated with time- and concentration-dependent PCDD/Fs. The toxic effect and oxidative stress caused by PCDD/Fs were evident, which could be indicted by the reduction in fresh mass, the increase in malondialdehyde (MDA) content, and the damage of tobacco cell ultrastructure. PCDD/Fs tolerance was correlated with changes in antioxidant system and hormones of tobacco cells. Superoxide dismutase (SOD) and peroxidase (POD) exhibited peak enzyme activities at the PCDD/Fs concentration of 1000 ng WHO98-TEQ g−1 fresh weight. Glutathione reductase (GR) enzyme activity increased monotonically at high level PCDD/Fs, but the activity of catalase (CAT) was only slightly affected at all treatment. Meanwhile, the exposure to PCDD/Fs resulted in the changes of hormones content. With the increase of exposure concentration of PCDD/Fs, the levels of indole-3-acetic acid (IAA) and abscisic acid (ABA) increased, whereas the concentration of jasmonates (JAs) decreased. The above results suggest that tobacco cells had the ability to cope with the oxidative stress induced by low concentration of PCDD/Fs through increasing the activities of antioxidant enzymes and alternating plant hormones levels. However, oxidative stress and toxicity would burst out when plant cells were exposed to the high levels of PCDD/Fs.  相似文献   
4.
盐胁迫下玉米幼苗ABA和GABA的积累及其相互关系   总被引:9,自引:0,他引:9  
盐胁迫下玉米幼苗内源脱落酸(abscisicacid,ABA)和γ-氨基丁酸(gamma-aminobutyricacid,GABA)含量增加,且ABA的积累先于GABA.用100μmol/L外源ABA和150mmol/LNacl处理使玉米幼苗内源GABA含量增加,NaCl和ABA同时处理时,对玉米幼苗GABA积累的诱导表现加合效应.ABA生物合成抑制剂氟草酮预处理后使盐胁迫诱导的GABA含量增加幅度减小,说明在盐胁迫下ABA调节GBAA积累.NaCl和ABA处理均刺激谷氨酸脱羧酶(GAD)的活性,推测盐胁迫下ABA通过调控GAD的活性而导致GABA积累.图6参18  相似文献   
5.
The present investigation determined the effects of epibrassinolide (EBL) on the levels of indole-3-acetic acid (IAA), abscisic acid (ABA), and polyamine (PA) and antioxidant potential of 7-d old Raphanus sativus L. cv. ‘Pusa chetki’ seedlings grown under Cr (VI) metal stress. Reduced titers of free (0.767 μg g−1 FW) and bound (0.545 μg g−1 FW) IAA in Cr (VI) stressed seedlings were observed over untreated control. Supplementations of EBL to Cr (VI) stressed seedlings were able to enhance both free (2.14-5.68 μg g−1 FW) and bound IAA (2.45-7.78 μg g−1 FW) concentrations in comparison to Cr (VI) metal treatment alone. Significant rise in free (13.49 μg g−1 FW) and bound (12.17 μg g−1 FW) ABA contents were noticed for Cr (VI) stressed seedlings when compared to untreated control. No significant increase in ABA contents were recorded for Cr (VI) stressed seedlings upon supplementation with EBL over Cr (VI) treatment alone. A significant increase in Put (18.40 μg g−1 FW) and Cad (9.08 μg g−1 FW) contents were found for 10−9 M EBL plus Cr (VI) metal treatments when compared to Cr (VI) treatment alone. Spermidine (Spd) contents were found to decline significantly for EBL treatment alone or when supplemented with Cr (VI) treatments over untreated controls and Cr (VI) treatment alone. Antioxidant levels were found to enhance, with glutathione (57.98 mg g−1 FW), proline (4.97 mg g−1 FW), glycinebetaine (39.01 μmol mL−1), ascorbic acid (3.17 mg g−1 FW) and phytochelatins (65.69 μmol g−1 FW) contents noted for EBL supplemented to Cr (VI) metal solution over Cr (VI) treatment alone. Reduced activities of guaiacol peroxidase (0.391 U mg−1 protein) and catalase (0.221 U mg−1 protein) and enhanced activities of glutathione reductase (7.14 U mg−1 protein), superoxide dismutase (15.20 U mg−1 protein) and ascorbate peroxidase (4.31 U mg−1 protein) were observed in seedlings treated with EBL plus Cr (VI) over Cr metal treatment alone. Reduced MDA (2.55 μmol g−1 FW) and H2O2 (33.24 μmol g−1 FW) contents were recorded for 10−9 M EBL supplemented to Cr (VI) stress over Cr (VI) treatment alone. Enhancement in free radical scavenging potential as indicated by higher values of 1,1-diphenylpicrylhydrazyl, deoxyribose and reducing power activity assays, and increased levels of phenols and soluble sugars also showed significant influence of EBL in alleviating Cr (VI) stress in radish seedlings.  相似文献   
6.
为探索UV-B辐射胁迫对大豆幼苗的伤害机制,采用水培法研究紫外辐射(UV-B,280~320 nm)胁迫作用对大豆(Glycine max)幼苗叶片气孔密度、气孔导度(GS)、脱落酸(ABA)含量、过氧化氢(H2O2)含量和过氧化氢酶(CAT)活性的影响.静态实验结果表明,UV-B辐射处理降低了大豆幼苗气孔密度,UV-B处理组气孔密度低于对照CK(喷水)组.动态曲线显示,较之CK(喷水),UV-B辐射使大豆幼苗GS下降,且最终达到较好的恢复效果;ABA和H2O2含量、CAT活性的变化趋势与GS的变化趋势不同,与CK(喷水)相比,UV-B辐射导致ABA和H2O2积累,CAT活性提高.研究表明,UV-B辐射抑制大豆幼苗水分代谢.  相似文献   
7.
二氧化硫(SO_2)是一种常见的大气污染物.前期研究表明,过氧化氢(H_2O_2)和一氧化氮(NO)参与调控SO_2诱导的胡杨细胞毒性.脱落酸(ABA)是一种植物逆境激素,目前关于ABA在植物细胞响应SO_2胁迫中的具体作用并不清楚.因此,本文以胡杨愈伤细胞为材料,采用SO_2衍生物处理,研究外源ABA在植物细胞SO_2毒性缓解中的作用及相关机制.结果发现:2 mmol·L~(-1)SO_2衍生物处理胡杨细胞9 h后,细胞电解质外渗率和细胞死亡率明显增加;外源施用5μmol·L~(-1)ABA可明显缓解SO_2对胡杨细胞的毒性,降低电解质外渗率和细胞死亡率.2 mmol·L~(-1)SO_2衍生物胁迫下,与SO_2单独处理组相比,添加外源ABA能够使胡杨细胞的抗坏血酸过氧化物酶(APX)和过氧化氢酶(CAT)活性分别提高23.9%和48.0%,从而减少胞内H_2O_2水平.此外,SO_2胁迫下,外施ABA后胡杨细胞的Pe Nia1、Pe Nia2基因表达受到明显抑制,细胞硝酸还原酶(NR)活性降低24.1%,胞内NO合成减少.以上结果表明,SO_2胁迫下,外源施加ABA可有效降低胡杨细胞内H_2O_2和NO水平,从而缓解SO_2对胡杨细胞的毒性.  相似文献   
8.
土壤干旱和内源ABA对夏玉米产量的影响   总被引:1,自引:0,他引:1  
对不同程度土壤干旱胁迫和夏玉米根、茎、叶中脱落酸含量变化对产量形成的影响进行了试验研究.充足底墒条件下播种后采用5个土壤水分等级(0~2m土壤相对湿度分别为>80%,70%~80%,60%~70%,50%~60%和40%~50%,处理代号分别为WT1~WT5),生育期内遮去自然降水.试验结果表明,轻度土壤干旱胁迫(WT3处理)下,由于表土层干旱促进了根源信号的产生、运输和累积,明显抑制了叶面积的发育和地上部分的干物质累积,降低了地上部分水分损失;同时该处理的玉米植株根系发育良好,不仅有效地利用了表土层的水分,而且根系向土壤深层延伸吸收利用土壤深层贮存的水分,有效地缓解了干旱胁迫和根信号对产量形成造成的负面影响,在土壤水分利用和获取之间达到了较好的平衡,提高了植株体的水分利用率并增加了收获指数.  相似文献   
9.
ABA对米槠和格氏栲种子发育的影响   总被引:7,自引:0,他引:7  
采用酶联免疫分析法(ELISA) 提取和测定米槠和格氏栲发育过程中果实内ABA含量,并用不同浓度ABA喂养,测定果实不同发育期对外源ABA的敏感性.用放射性同位素法测定ABA对贮藏蛋白质的积累作用,结果表明:在米槠和格氏栲种子发育过程中内源ABA 含量逐渐上升,两者均在10 月5 日达到峰值,米槠为1648 ngg,格氏栲为1 468 ngg,随后ABA含量均逐渐下降.果实成熟采收时,c(ABA) 仅为高峰时的19.随着果实的发育对外加ABA的敏感性逐渐变小,c(ABA)=10-4 molL-1 可以完全抑制10 月25 日( 米槠) 和10 月15 日( 格氏栲) 前种子发芽,但对完全成熟的种子c(ABA)=10-2 molL-1 亦不能抑制发芽.ABA 对成熟前期胚的贮藏蛋白质合成无影响,但能促进成熟中后期胚的贮藏蛋白质的积累作用,ABA维持米槠和格氏栲贮藏蛋白质合成和积累作用表现在转录水平上.  相似文献   
10.
长穗颈(eui)水稻上部节间伸长与植物激素的关系   总被引:3,自引:0,他引:3  
选取含有诱变的长穗颈基因eui1、eui2和野生型基因Eui的水稻(OryzasativaL.)协青早保持系3个等基因系,通过供试植株在不同生育期的GA1和ABA含量测定及喷施GA合成抑制剂,并辅之器官删除试验等方法,探索长穗颈水稻上部节间伸长的生理机制.结果表明,在抽穗期,含eui1的协青早保持系XeB1幼穗和剑叶里的GA1含量显著增加,分别约为对照协青早B的16倍和3.4倍,其GA1/ABA比值也明显增加;含eui2的XeB2幼穗和剑叶里的GA1含量显著提高,但仅在剑叶里GA1/ABA比值明显增加,其幼穗内的GA1水平显著低于XeB1.GA合成抑制剂S3307处理使XeB1和XeB2的株高生长均受到严重抑制.删除幼穗使XeB1最上节间伸长的受抑程度远大于XeB2和XB.由此推测,在抽穗期,eui1能使水稻自身产生GA1,高含量的GA1诱导了长穗颈水稻最上节间的剧烈伸长;在促进最上节间的伸长方面eui1强于eui2.图5表1参12  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号