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1.
紫外辐射对孔石莼抗氧化酶活性及其同工酶表达的影响 总被引：1，自引：0，他引：1
潮间带海藻不可避免地要遭受UV-B的胁迫。本研究以孔石莼(Ulva pertusa)为试材,研究了UV-B胁迫对其抗氧化酶体系中SOD、CAT、POX、APX、GR、GPX活性及前4种酶的同工酶表达的影响。结果显示:SOD、CAT、POX酶活性应激反应较为迅速;APX活性始终保持较稳定水平;GR、GPX酶应激表达启动稍晚,酶活高峰在处理中期6d时出现。SOD同工酶谱有4条酶带,在UV-B3种剂量处理下,SODⅠ及SODⅡ同工酶活性有所增加;POXⅡ同工酶活性呈小幅增加;在UV-B诱导下,CAT产生了2条新的同工酶谱带CATⅠ及CATⅡ;APX同工酶仅有1条谱带,在UV-B处理下与对照差异不大。抗氧化成分As A及GSH含量在处理前中期与对照相近。孔石莼的特定增长率(SGR)在1.6 kJ/(m~2·d)、4.8 kJ/(m~2·d)和9.6kJ/(m~2·d)3种剂量UV-B辐射处理下均呈下降趋势,且在后两种剂量处理下降低尤为显著,而相应的H_2O_2及TBARS含量呈不同程度增加。上述结果表明:孔石莼对UV-B辐射具有一定程度的耐受性,可以通过提高酶促过氧化体系活性来应答UV-B导致的氧化胁迫,并且酶活性变化体现出剂量和时间效应。 相似文献
2.
利用生物化学的方法,研究了赤潮异弯藻、亚历山大藻和中肋骨条藻抗氧化酶活性对UV-B辐射增强的响应变化。结果表明:(1)不同赤潮微藻的抗氧化酶活性对UV-B辐射增强的响应变化是不同的。(2)不同的抗氧化酶活性对UV-B辐射增强的响应变化同样存在明显的差异。(3)与过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)相比,超氧化物歧化酶(SOD)活性对UV-B辐射增强的响应最敏感,谷胱甘肽过氧化物酶(GPX)活性的响应变化最不明显。3种赤潮微藻SOD活性的变化是指示UV-B辐射增强的优选生物学指标。 相似文献
3.
粉叶马尾藻(Sargassum glaucescens)是台湾地区潮间带的重要大型藻类,其对紫外线增强的生理响应特征尚不清楚。本研究关注粉叶马尾藻在急性紫外线辐射(Ultraviolet radiation B,UVB)下的生理指标变化,探索了粉叶马尾藻在急性UVB辐照下抗氧化系统的瞬时反应过程。结果表明:低强度组[0.5W/(m2·s)]藻体在24h内未出现显著氧化损伤和蛋白质含量变化,但是细胞活力在辐照12h后显著降低,藻体超氧化物歧化酶(SOD)酶活性随辐照时间延长而降低,过氧化氢酶(CAT)酶活性呈现升高后下降的趋势,抗坏血酸过氧化物酶(APX)酶活性没有出现显著降低;高强度组[2W/(m2·s)]藻体在辐照3h后藻体出现明显氧化损伤,6h后细胞活力和蛋白质含量显著降低,藻体SOD酶活性随辐照时间延长而降低,CAT和APX酶活性呈现升高后降低的趋势,辐射12h后即显著降低。低强度UVB辐射对粉叶马尾藻的影响相对较小,表明粉叶马尾藻对UVB辐射具有一定耐受性;而高强度UVB辐射的影响较为显著,意味着UVB辐射的持续增强将超出粉叶马尾藻的耐受限度,进而造成不利影响。本研究结果初步揭示了粉叶马尾藻对于急性UVB辐射的增强的生理响应特征,为进一步研究UVB辐射增强的生态学效应提供参考依据。 相似文献
4.
《中国海洋大学学报(自然科学版)》2015,(12)
以三角褐指藻(Phaeodactylum tricornutum)为材料,在连续4d内,以100、400、700μg/L 3个剂量的苯并[α]芘(B[α]P)对三角褐指藻进行胁迫试验,分析苯并[α]芘对三角褐指藻的毒性效应,测定三角褐指藻的抗坏血酸-谷胱甘肽(AsA-GSH)循环非酶成分、含量及酶活性。研究表明:随着B[α]P浓度的提高和胁迫时间的延长,B[α]P对三角褐指藻的生长抑制作用逐渐增强;藻细胞内丙二醛(MDA)含量及总抗氧化能力(TAOC)显著升高,两者与胁迫强度的相关性系数分别为0.960和0.894;同时,AsA-GSH循环中的非酶成分抗坏血酸(AsA)、谷胱甘肽(GSH)含量增加,相关酶谷胱甘肽还原酶(GR)、抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)和单氢抗坏血酸还原酶(MHAR)活性普遍增加,其中,GSH含量、GR、APX和DHAR活性与藻细胞内MDA含量相关性系数分别为0.744、0.852、0.652和0.600。结果表明:AsA-GSH循环是三角褐指藻细胞对抗苯并芘胁迫、猝灭活性氧、降低膜脂过氧化的重要方式;细胞内AsA含量、GR活性及APX活性对苯并芘胁迫响应迅速、变化显著,是潜在的生物指示物。 相似文献
5.
以坛紫菜(Pyropia haitanensis)Z-61叶状体为材料,检测了高盐(110)胁迫与低盐(0)胁迫处理不同时间(0、4、8、24h和恢复4h)后叶状体中的羟自由基(·OH~-)清除能力、过氧化氢(H_2O_2)含量、丙二醛(MDA)含量、超氧阴离子(O_2~-·)含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、抗坏血酸过氧化物酶(GSH)活性以及叶绿素荧光参数[包括PS II最大光化学效率(Fv/Fm)、表观光合电子传递效率(ETR)、非光化学荧光猝灭系数(NPQ)、实际光合作用效率Y(II)]的变化,以探究坛紫菜叶状体对不同盐度海水的耐受机制.结果表明,在高盐和低盐胁迫下,H_2O_2的含量和·OH~-的清除能力随时间增加而呈现逐渐上升的趋势,而O_2~-·的含量在胁迫4h显著升高后无显著变化.且相比于高盐(110),低盐(0)胁迫下坛紫菜叶状体会产生更多H_2O_2、O_2~-·和·OH~-,膜脂过氧化物丙二醛(MDA)含量增加更明显,说明低盐胁迫引起坛紫菜叶状体的氧化损伤要显著高于高盐胁迫.高盐胁迫24h后,SOD的活性达到了最大,CAT、抗坏血酸过氧化物酶(APX)、谷胱甘肽(GSH)的活性均呈现先上升后下降的变化趋势.低盐胁迫下,SOD、GSH的活性均不断增加,CAT、APX的活性先上升后下降.此外,低盐和高盐胁迫下,随时间的增加,叶绿素荧光参数均明显下降.上述结果表明,高盐和低盐胁迫下,坛紫菜叶状体的光合作用受到抑制,机体通过维持较高的抗氧化酶活性以提高活性氧的清除能力,进而保证藻体的正常存活. 相似文献
6.
以潮间带大型海藻孔石莼(Ulvapertusa)及鼠尾藻(Sargassumthunbergii)为试材,研究了不同Cu~(2+)浓度(0, 0.5, 1.0, 1.5, 2.0 mg/L)胁迫下海藻中叶绿素含量、光合特性和ATP酶活性的响应变化。结果表明,随Cu~(2+)浓度增加,孔石莼及鼠尾藻的光合色素含量、叶绿素荧光参数包括光能利用效率(alpha)、最大相对电子传递速率(rETRm)、半饱和光强(IK)及PSⅡ最大光能转化效率(F_v/F_m)随胁迫浓度升高均呈下降趋势,其中孔石莼F_v/F_m下降幅度更大;2种海藻中Na~+K~+-ATP及Ca~(2+)Mg~(2+)-ATP酶活性总体上随Cu~(2+)浓度的升高亦呈降低趋势,且孔石莼降低幅度尤为显著。这些结果表明,随胁迫程度加剧,孔石莼及鼠尾藻光合作用受抑,代谢酶活性降低,藻体遭受不可逆的严重损伤,处理体现出较明显的剂量效应;二者相比,鼠尾藻相比孔石莼对铜胁迫具更强的耐受性;叶绿素荧光参数F_v/F_m测定结果极其稳定且与胁迫程度相关极显著,可作为海藻生长及生理代谢对重金属耐受性的有效评价指标。 相似文献
7.
南极上空臭氧层的破坏导致了紫外辐射日益增强,高强度的UV-B辐射会造成细胞中DNA的损伤,影响蛋白质、脂类和色素的代谢过程。生长在南极的绿藻具有一系列防御机制以应对增强的UV-B辐射,其中类菌胞素氨基酸(Mycosporine-like amino acids, MAAs)是一类重要的紫外防御物质。为探究类菌胞素氨基酸对UV-B辐射的响应,本文以南极冰藻(Chlamydomonassp.ICE-L)、针丝藻(Raphidonema nivale Lagerheim, NIES-2290)和胶球藻(Coccomyxa subellipsoidea E.Acton, NIES-2166)三种生活在南极的绿藻为材料,采用UV-B辐射胁迫(强度0.35 W/m~2,短时处理3 h),并通过液相色谱-质谱联用法检测类菌胞素氨基酸的种类和含量的变化。Mycosporine-glycine为三种南极绿藻中共有的MAAs,在UV-B辐射胁迫下三种南极绿藻中Mycosporine-glycine含量变化不尽相同,表明不同的南极绿藻中MAAs对UV-B辐射的响应各有其特性。首次在绿藻(南极冰藻和胶球藻)中检测到Gadusol。Gadusol作为MAAs的合成前体,它的合成积累使得生活在海冰环境的南极冰藻和胶球藻具有良好的抗UV-B辐射能力。其中南极冰藻抗紫外能力最强,这可能得益于不同MAAs间的动态转化,含量升高的Palythine及Usujirene/Palythene可能对南极冰藻的紫外屏蔽起着至关重要的作用。 相似文献
8.
夏季高温是限制龙须菜(Gracilariopsis lemaneiformis)生长和发育的一个主要问题。本研究以野生龙须菜作为材料,经过28℃的热锻炼预处理72 h,再分别置于32、36、40℃高温胁迫24 h,并测定了高温胁迫条件下龙须菜的丙二醛(MDA)、过氧化氢(H2O2)和可溶性蛋白质的含量,以及超氧化物歧化酶(SOD)活性和抗坏血酸(AsA)水平等生理指标,研究了龙须菜对高温胁迫的响应。结果表明:热锻炼能维持藻体较低的MDA含量,降低H2O2的产生速率,缓解藻体的膜脂过氧化伤害;同时热锻炼缓解了可溶性蛋白质的降解,增加了SOD酶的比活力,缓解了AsA的下降速率,说明热锻炼能缓解高温胁迫对藻体的伤害,有效地提高了龙须菜对高温胁迫响应的能力。 相似文献
9.
本实验以新月菱形藻为受试生物,研究了低浓度不同粒径TiO2颗粒(21nm、60nm和400nm)对海洋微藻生长、抗氧化酶活性(超氧化物歧化酶SOD、过氧化氢酶CAT和过氧化物酶POD)、脂质过氧化产物(MDA)含量的影响,并测定了相应的活性氧自由基(ROS)的含量,初步探讨了TiO2颗粒对海洋微藻的作用机制。结果表明,1mg/L TiO2颗粒对新月菱形藻生长的抑制作用随着粒径的减小而逐渐增强,第48h、72h、96h呈现出显著的纳米效应。TiO2颗粒可以诱导藻细胞内ROS的含量增加,对藻细胞产生氧化胁迫,新月菱形藻的抗氧化酶活性发生应激响应,以清除过量的ROS,但剩余的ROS对藻细胞产生氧化损伤,导致MDA含量升高,并且纳米级TiO2颗粒对新月菱形藻的氧化损伤大于微米级颗粒。在不同粒径TiO2颗粒的胁迫下,藻细胞SOD和CAT活性的响应也存在差异。本研究将为开展人工纳米材料对海洋生态系统影响的潜在风险评估提供科学依据。 相似文献
10.
研究了暴露于微小亚历山大藻藻液中的黑鲷仔鱼其超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、过氧化物酶(CAT)和Na+-K+-ATPase酶活性在4d时间内的变化,结果表明,微小亚历山大藻藻液对仔鱼的GSH-PX和CAT活性诱导作用明显,尤其对处于染毒时间2d内,这种作用较强,但随着实验时间的延长又表现出抑制作用。微小亚历山大藻藻液对SOD也有强烈的诱导作用,这种作用可持续3d,但随后则表现为抑制作用。仔鱼的3种酶活性与染毒的藻液均符合较明显的剂量-效应关系,即实验藻液浓度越大,对酶活性的抑制率越低,对生物毒性越大。但藻液对于Na+-K+-ATPase酶却表现出强烈的抑制作用,显示出浓度-效应关系。其与上述3种酶的活力变化可以一起作为水体中藻液污染的生物指示器。 相似文献
11.
The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level. 相似文献
12.
We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances
using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium
partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and
in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority
accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative
abundances of organic and inorganic carbon as an index of the carbon cycle stability. 相似文献
13.
We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the
Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of
rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the
transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic
regime of the sea.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
14.
V. A. Ivanov S. P. Lyubartseva N. Mikhailova N. B. Shapiro 《Physical Oceanography》2001,11(6):509-524
We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an
ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics
is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of
a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic
elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as
a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water
area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the
shelf zone and open sea.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
15.
Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m3 from 1 km of coast in the wide tidal flats and <50 m3 on the steep coasts) are delivered to the water area. 相似文献
16.
Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east 总被引：2，自引：0，他引：2
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry
dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly
goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with
the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then
passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state. 相似文献
17.
I. E. Timchenko A. A. Primalenny V. D. Yarin E. F. Vasechkina E. M. Igumnova 《Physical Oceanography》2001,11(4):367-378
We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of
the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption
(fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by
the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with
application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem,
which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge,
water exchange with the Black Sea, etc.).
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
18.
I. G. Ostrovskaya 《Physical Oceanography》1992,3(5):397-403
Three mathematical models are considered: a two-dimensional model for calculating the concentration fields of the ecosystem components on the shelf of the Republic of Guinea, a pointwise model for the annual variation of the components, and a two predators-prey model. These models are used to study the effect of hydrodynamic conditions on the state of the shelf ecosystem and for research into the causes which distort the balance between marketable and unmarketable fish.Translated by Mikhail M. Trufanov. 相似文献
19.
Al. A. Shreider 《Oceanology》2007,47(1):91-103
The first data on the temporal evolution of the slope of the buried depression of the Black Sea are obtained. The sharp change in the rate of the decrease in the slope steepness that occurred in the Late Miocene-Pliocene time reflects a reorientation of the vector of mutual movement and a related intensification of the collision between the Arabian and Eurasian lithospheric plates. 相似文献
20.
The study of the sedimentary body of the Bransfield Strait has made it possible to identify several sedimentary complexes, to construct the first electronic charts for the acoustic basement, and to establish four stages of the evolution of its floor, which updates the previous knowledge about the formation of the strait. At the first stage, there was an increase in tension stresses that were accompanied by the local splits of the continental crust at the periphery of the Antarctic Peninsula. At the second stage, a graben-like structure filled with the Lower stratigraphic complex was formed northward of the Antarctic Peninsula. At the third stage, the continuing processes of extension led to intensive explosive activity of the growing volcanic structures and filling of the graben with sediments of the Middle seismostratigraphic complex. The fourth stage, which has continued until recently, is characterized by quasi-linear localization of the major centers of volcanic activity in the band closer to the South-Shetland Islands and the formation of the Upper seismostratigraphic sedimentary complex. The evolution of the floor of the Bransfield Strait reflects the process of penetration of the American-Antarctic ridge to the continental lithosphere of the Antarctic Peninsula for the last million years. 相似文献