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1.
镉是植物生长的非必需元素,它具有很大的生物毒性,与其它重金属相比,更易被植物吸收积累。通过采用营养液水培试验的方法,研究了外源一氧化氮(Nitric oxide,NO)对不同浓度Cd^2+(100μmol L^-1.300μmol L^-1,500μmol L^-1)胁迫下黄瓜幼苗生长、叶片光合特性以及活性氧代谢的影响。结果表明:300μmol L^-1NO供体硝普钠(Sodium nitrop russide,SNP)能显著缓解镉胁迫时黄瓜植株造成的伤害,对300μmol L^-1 Cd^2+处理的黄瓜幼苗缓解效果最好,可提高幼苗的生长量,增强幼苗叶片超氧物歧化酶(SOD)、过氧化物酶(POD)活性;提高了叶片叶绿素和脯氨酸(Pro)含量;降低了叶片内二醛(MDA)含量。  相似文献   

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采用营养液水培的方法,研究了外源一氧化氮(Nitric oxide, NO)对50mmol•L-1NaCl胁迫下黄瓜幼苗生长、活性氧代谢和光合特性的影响。结果表明:10~400μmol•L-1 NO供体硝普钠(Sodium nitroprusside, SNP)能显著缓解NaCl胁迫对黄瓜植株造成的伤害,100μmol•L-1 SNP缓解效果最好,可提高幼苗的生长量,增强幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性,提高了叶片叶绿素和脯氨酸(Pro)含量、净光合速率(Pn)、蒸腾速率(Tr)及气孔导度(Gs);降低了叶片丙二醛(MDA)和过氧化氢(H2O2)的含量、超氧阴离子(O•-2)的产生速率、质膜透性和胞间二氧化碳浓度(Ci)。  相似文献   

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采用水培方法,研究了外源一氧化氮(NO)供体硝普钠(SNP)对300 μmol·L-1 LaCl3胁迫下黑麦草幼苗生长和根系活性氧代谢的影响。结果表明:在LaCl3胁迫下,喷施50 μmol·L-1 SNP能够抑制镧(La)从黑麦草根系向地上部的转运,缓解La对幼苗生长的抑制作用;提高幼苗根系超氧化物歧化酶和抗坏血酸过氧化物酶活性,降低过氧化物酶活性及谷胱甘肽、脯氨酸、H2O2、丙二醛含量、超氧阴离子产生速率和质膜相对透性,对过氧化氢酶活性和抗坏血酸含量无显著影响。表明NO可通过活性氧代谢的调节,缓解高浓度La胁迫对黑麦草幼苗生长的抑制作用。  相似文献   

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研究了外源一氧化氮(nitric oxide,NO)对盐胁迫下多年生黑麦草幼苗生长及相关生理指标变化的影响。结果表明,与对照相比,50~200μmol·L-1NO供体硝普钠(sodium nitroprusside,SNP)可缓解盐胁迫对黑麦草幼苗生长的抑制作用,其中100μmo·lL-1SNP缓解作用最强。外施SNP显著缓解了盐胁迫导致的叶片相对电导率、K+与Na+比率、丙二醛含量和活性氧水平的增加,提高了盐胁迫下幼苗叶子中脯氨酸含量和超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和过氧化物酶等抗氧化酶的活性。这些结果说明,NO可能通过降低细胞吸收Na+的量、增加细胞吸收K+的量和脯氨酸含量以及激活抗氧化保护酶等减轻了盐对黑麦草的伤害,提高了黑麦草的抗盐性。  相似文献   

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采用溶液培养方法研究外源NO供体硝普钠(SNP)对Cd^2+胁迫下辣椒幼苗生长和生理特性影响的结果表明:75μmol·L^-1SNP能在一定程度上缓解较高浓度Cd^2+对辣椒幼苗生长、叶中Chla和Chlb含量以及根系活性的抑制作用,降低丙二醛(MDA)含量,增强超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性。  相似文献   

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研究外源一氧化氮(NO)供体硝普钠(sNP)对干旱胁迫下小麦幼苗叶片ATP酶活性和膜脂过氧化影响的结果表明,15%聚乙二醇.6000(PEG-6000)模拟的干旱胁迫下小麦幼苗叶中H^+-ATP酶和Ca^2+.ATP酶活性显著升高后迅速下降,硫代巴比妥酸反应产物(TBARs)和质量膜透性增加;0.1mm01.L^-1 SNP可提高干旱胁迫下小麦幼苗叶中超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(cAT)活性,降低超氧阴离子(O2^-)和过氧化氢(H2O2)水平,缓解膜脂过氧化,稳定生物膜的结构和功能,H^+-ATP酶和Ca^2+-ATP酶也可以保持更高的活性。  相似文献   

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以盐敏感型黄瓜品种津春4号为材料,采用水培方法研究了叶面喷施不同浓度(0.5、1.0和1.5 mmol·L-1)氯化胆碱(CC)对NaCl胁迫(75 mmol·L-1)下黄瓜幼苗鲜重、叶片叶绿素、渗透调节物质含量及活性氧代谢系统的影响.结果表明:(1)单独CC处理可提高黄瓜叶片的叶绿素、可溶性糖和可溶性蛋白含量以及过氧化氢酶(CAT)与过氧化物酶(POD)活性,降低O2·-产生速率,但对植株鲜重及超氧化物岐化酶(SOD)活性影响不大;(2)NaCl胁迫处理增加了黄瓜幼苗叶片中可溶性糖和可溶性蛋白含量,增强了SOD、POD和CAT活性,提高了O2·-产生速率及丙二醛(MDA)的含量,但同时降低了叶绿素含量与植株鲜重;(3)盐胁迫前CC预处理可缓解黄瓜幼苗叶绿素含量和植株鲜重的下降、以及MDA含量和O2·-产生速率的上升趋势,且进一步提高了盐胁迫下黄瓜叶片中SOD、POD和CAT活性.因此,适宜浓度的氯化胆碱可显著提高盐胁迫下黄瓜叶片的抗氧化酶活性,提高清除活性氧的能力,缓解盐胁迫对黄瓜幼苗细胞膜的伤害,增强黄瓜幼苗的耐盐性.  相似文献   

8.
研究了外源一氧化氮(NO)供体硝普钠(SNP)对NaCl处理下红树植物秋茄(Kan-deliacandel)幼苗叶片中抗氧化酶活性、抗氧化物质及脯氨酸含量的影响。结果表明:NaCl处理下,秋茄幼苗叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)等4种活性氧清除酶的活性均受到明显抑制(P<0.05),SNP可以不同程度地恢复SOD、POD、CAT的活性,但对APX活性影响不大;SNP提高谷胱甘肽(GSH)及类胡萝卜素(Car)的含量,促进脯氨酸含量的上升,显著降低叶片中过氧化氢(H2O2)和丙二醛(MDA)的累积。表明外源NO可以缓解NaCl处理诱导的秋茄幼苗叶片氧化损伤,降低膜脂过氧化水平,有利于秋茄适应盐生环境。  相似文献   

9.
采用营养液砂培方法,研究外源一氧化氮(NO)供体硝普钠(SNP)对NaHCO3胁迫下黑麦草幼苗生长、活性氧代谢和渗透溶质积累的影响.结果表明:60 μmol·L-1 SNP能够缓解100 mmol·L-1NaHCO3胁迫对黑麦草幼苗生长的抑制作用,减缓NaHCO3胁迫导致的叶片O2产生速率、H2O2和丙二醛(MDA)含量的增加,提高NaHCO3胁迫下幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、质膜H+-ATP酶的活性和谷胱甘肽(GSH)、可溶性糖、可溶性蛋白质和脯氨酸的含量及K+/Na+比,降低过氧化氢酶(CAT)活性和抗坏血酸(AsA)含量,对游离氨基酸含量影响不大.上述结果表明,NO可能通过激活抗氧化系统活性、促进渗透溶质积累和改善Na+、K+平衡等缓解碱胁迫对幼苗的伤害,从而提高黑麦草的耐碱性.  相似文献   

10.
外源一氧化氮供体SNP对黑麦草种子萌发和幼苗生长的影响   总被引:13,自引:1,他引:12  
采用水培试验,研究了不同浓度NO供体硝普钠(SNP)对黑麦草种子萌发和幼苗生长的影响。结果表明:50和100μmol.L-1SNP促进了黑麦草种子的发芽率、幼苗干物质积累速率、萌发种子α-淀粉酶活性、幼苗叶片可溶性蛋白质及叶绿素含量的提高。根和叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性及还原型谷胱甘肽(GSH)、抗坏血酸(ASC)含量增加,超氧阴离子(O.2-)积累速率和过氧化氢(H2O2)含量下降,丙二醛(MDA)积累降低。高浓度SNP(500~2000μmol.L-1)抑制种子的萌发和幼苗生长,幼苗叶绿素、可溶性蛋白质及GSH、ASC含量下降,MDA含量和H2O2、O.2-产生速率提高,SOD、POD和APX活性降低,但叶片CAT活性升高。推测NO可能通过提高种子淀粉酶活性和幼苗活性氧清除能力,促进黑麦草种子的萌发和幼苗生长。  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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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   

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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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