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1.
Experimental evaluations about the impact of anchors of small vessels have previously shown that each anchoring can on average damage up to six shoots of Posidonia oceanica, removing small amount of biomass and, at the same time, interrupting continuity among shoots. The aim of the paper was to investigate the response of P. oceanica to different damage intensity at two levels of substrata compactness. Three treatments were considered: control (no damage); low damage (simulated anchor damage by three strokes of a hoe); and high damage (six strokes). Disturbance was higher where the substratum was highly penetrable and after one year significant variation was observed among treatments for both the number of leaves per shoot and shoot density. Conversely, the number of leaves per shoot by the end of the study was similar among all treatment combinations, suggesting that this was the only phenological feature that recovered, and probably the only result that through clonal integration could be achieved. These data strongly highlighted the role that anchoring might have on the slow growing seagrass P. oceanica meadow. 相似文献
2.
本文探究环境低氧对军曹鱼(Rachycentron canadum)氧化应激和能量利用指标的影响，为军曹鱼的健康养殖提供参考依据。通过设置低氧胁迫–恢复实验，将军曹鱼幼鱼(平均体质量(220.67±20.73)g)在低氧((2.64±0.25)mg/L)胁迫3 h及复氧((6.34±0.15)mg/L)8 h、24 h和48 h后，测定其肝脏和肌肉组织的氧化应激与能量利用指标。结果显示，低氧胁迫后，肝脏中丙二醛（Malondialdehyde，MDA)、过氧化氢酶(Catalase，CAT)和谷胱甘肽还原酶(Glutathione Reductase，GR)活力均显著低于对照组(p<0.05)，乳酸脱氢酶(Lactate Dehydrogenase，LDH)活性显著高于对照组(p <0.05)；肌肉中MDA和脂质过氧化物(Lipid Peroxidase，LPO)活性均显著低于对照组(p<0.05)，超氧化物歧化酶(Superoxide Dismutase，SOD)和LDH活性均显著高于对照组(p<0.05)；肌糖原和肝糖原含量极显著低于对照组(p<0.01)。复氧过程中，肝脏和肌肉中MDA、LPO、SOD、CAT、谷胱甘肽过氧化物酶(Glutathione Peroxidase，GPx)和GR含量均出现不同程度的升高；肝糖原在复氧24 h后显著高于对照组(p<0.05)，复氧48 h后显著低于对照组(p<0.05)；肌糖原在复氧8 h、24 h和48 h后均显著低于对照组(p<0.05)。研究表明，低氧胁迫能够对军曹鱼幼鱼机体造成一定的氧化损伤，肝脏和肌肉组织的酶活力和能量供应发生变化；低氧胁迫后的再复氧环境，对机体造成更为强烈的氧化损伤，可通过自身生理调节逐渐恢复到正常水平。 相似文献
3.
海水中的高溶解氧浓度、低温和UV辐射导致了氧胁迫是北极海洋细菌面临的主要胁迫因素之一。本文对北极细菌Pseudoalteromonas sp.A2对H2O2导致的氧胁迫的应答特征进行了转录组测序和基因差异表达的比较分析,以期发现与氧胁迫相关的关键功能基因。研究表明,与对照组相比,1 mmol/L的H2O2可导致菌株A2转录组的很大变化,包括109个基因的显著上调与174个基因的显著下调。COG分析表明,在功能已知的基因中,与转录后修饰、蛋白质转换和分子伴侣相关的基因大部分显著上调,而与氨基酸运输和代谢等相关基因则大部分显著下调。值得指出的是,有18个与鞭毛相关的基因和4个与热激蛋白相关的基因显著上调;同时,有9个与细胞色素和细胞色素氧化酶相关的基因和5个与TonB依赖受体相关的基因显著下调。在GO分析表明具有抗氧化活性的18个基因中,只有1个基因的表达显著上调,而有2个显著下调。简言之,RNA-Seq表明,除了传统的抗氧化基因和应激蛋白外,鞭毛相关基因和功能未知基因在菌株Pseudoalteromonas sp.A2的氧胁迫适应性中起着重要作用。该转录组分析和氧胁迫相关基因的发现有助于了解北极细菌的氧胁迫适应机制。 相似文献
4.
Seasonal Changes in Nitrogen, Free Amino Acids, and C/N Ratio in Mediterranean Seagrasses 总被引：2，自引：0，他引：2
Abstract. Seasonal changes in nitrogen, free amino acids, and carbon were investigated in the three Mediterranean seagrasses Posidonia oceanica, Cymodocea nodosa , and Zostera noltii. Leaves, rhizomes, roots, as well as dead plant material were analysed separately. Highest N-concentrations were obtained in the winter months, regardless of species or plant part. In contrast to the other two species, the N-content in Posidonia was higher in the rhizomes than in the leaves.
In the investigated species, marked differences in the free amino acid (FAA) composition were detected between species: Proline, lacking in Posidonia , was the main component in Cymodocea. In Posidonia , FAA decreased from 320umol g-1 (dry wt) in leaf sheaths to 1.5 umol g-1 (dry wt) in the leaf tips. The function of proline as a possible storage and/or stress metabolite is discussed.
High C/N values in dead P. oceanica and C. nodosa rhizomes as well as in P. oceanica wrack seem to be related to considerable resistance to decomposition. Low C/N ratios did not increase in detached C. nodosa and Z. noltii leaves, which began to decompose shortly after detachment from the plants. 相似文献
In the investigated species, marked differences in the free amino acid (FAA) composition were detected between species: Proline, lacking in Posidonia , was the main component in Cymodocea. In Posidonia , FAA decreased from 320umol g
High C/N values in dead P. oceanica and C. nodosa rhizomes as well as in P. oceanica wrack seem to be related to considerable resistance to decomposition. Low C/N ratios did not increase in detached C. nodosa and Z. noltii leaves, which began to decompose shortly after detachment from the plants. 相似文献
5.
Investigations on seasonal variation in oxidative stress biomarkers were carried out on the natural population of green-lipped mussel Perna viridis collected from Bambolim beach area of Goa. Oxidative stress indices such as lipid peroxidation (LPX), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transferase (GST), glutathione reductase (GR), reduced glutathione (GSH) and ascorbic acid (ASA) were measured in gills and digestive gland of P. viridis during February, May, August and November. The present study reveals two important aspects regarding the antioxidant defence status of tissues of P. viridis. Firstly, antioxidant capacity of tissues of P. viridis exhibits seasonal variation. Secondly, various components of antioxidant capacity such as oxidative stress markers, levels of antioxidant enzymes and small antioxidant molecules vary differently in tissues with respect to different seasons. Although the oxidative stress status of gills and digestive gland of P. viridis expressed in terms of LPX and H2O2 was the lowest in February, its level was maximal in gills and digestive gland during May and November, respectively. While activities of SOD and GPX of tissues of P. viridis were found to be low in August, activities of CAT and GR were recorded to be low in February. GST activity in gills although remained high in February, in digestive gland elevated values were recorded in August and November. A seasonal variation in the levels of small antioxidant molecules was also noticed. Among non enzymatic antioxidants ASA content of tissues was maximal in May and August in comparison to February and November, but GSH remained high in November. It therefore appears that environmental factors may play a crucial role in regulating the oxidative stress capacity of tissues of P. viridis. 相似文献
6.
Abstract. The supply of nitrogen (N) often limits the productivity of marine macrophytes. In vitro and in vivo assays of glutamine synthetase (GS) activity were employed to investigate patterns of N assimilation by the Mediterranean seagrass Posidonia oceanica (L.) DELILE. Biomass-specific GS activity wa measured in root tissue, in leaves within a shoot, in shoots collected at two sites during two season and over a depth range of 5–33 m. Root tissue was less important than shoot tissue in assimilating inorganic N in P. oceanica , due both to the small roots' biomass (ca. 3% of total plant biomass and greatly lower (10- to 50-fold) GS activities. While the GS activity and N assimilatory potentia (biomass × GS activity; μmol N-h--1 ) were greatest in leaf 2, leaves 1 and 3–5 assimilated N a significant rates. Shoots from a site characterized by elevated N availability in the winter water column and no significant sediment N reservoir exhibited GS activities that were 9-times higher than shoot from a more oligotrophic site. Shoot GS activities in July increased linearly from 5 to 33 m and wer correlated with light availability as defined by Hsat , (daily period during which photosynthetic reaction are light-saturated). This may represent metabolic compensation by P. oceanica to maintain N influx. Factors contributing to the ecological success of P. oceanica include the ability to assimilate N under conditions of severe light limitation (< 35 μmol photons. m-2 . s-1 ), and metabolic plasticity to ensur the de novo generation of N-containing organic compounds. 相似文献
7.
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
8.
谷胱甘肽过氧化物酶(Glutathione peroxidase,GPx)是生物体内重要的抗氧化酶,能防止过氧化氢对生物体的氧化应激。该研究利用RACE技术获得了斑节对虾(Penaeus monodon)GPx3a(PmGPx3a)的全长c DNA序列,进行了相关生物信息学分析。作者利用荧光定量PCR方法研究了PmGPx3a在斑节对虾不同组织的表达情况。探究了PmGPx3a在不同胁迫条件下(盐度、重金属和细菌)的表达情况。结果表明PmGPx3a c DNA全长1135 bp,其中开放阅读框(ORF)长651 bp,预测编码216个氨基酸。PmGPx3a推导的氨基酸序列与其他动物的GPx3a氨基酸序列具有高度一致性。实时定量PCR结果显示,在高低盐胁迫下,PmGPx3a在肝胰腺中相对表达量都为上升的(p0.05)。在铜、锌、铬胁迫中,鳃中的PmGPx3a的相对表达量总体呈现下降趋势,在肝胰腺中呈现上升趋势。在哈维弧菌(Vibrio harveyi)刺激下,PmGPx3a在血淋巴中的相对表达量总体呈现上升趋势,24 h后表达量最大,显著高于对照组2.2倍(P0.05)。以上研究结果表明,PmGPx3a基因参与了斑节对虾对环境胁迫和氧化应激的适应性反应。 相似文献
9.
为明确不同盐度胁迫下香螺的生理生态学响应及其适应机制,本文采用行为学、组织学和生物化学手段研究了不同盐度条件下(16、20、24、28、32、36、40、44、48)香螺的行为、病理损伤以及抗氧化酶活性。结果显示,在高盐和低盐胁迫下,香螺出现应激反应,摄食率下降,死亡率升高。随盐度升高,香螺的总抗氧化能力先升高后降低,在盐度32时达到峰值;香螺鳃的过氧化氢酶(CAT)活力和超氧化物歧化酶(SOD)活力呈先降低后升高的趋势;肾的CAT和SOD活力呈先升高后降低的趋势。组织切片结果显示,在高盐和低盐胁迫下,香螺嗅检器和鳃丝的形态呈现显著变化,黏液细胞数量均增加。上述结果表明,盐度显著影响香螺的生理生态反应,且香螺可通过行为变化、调节抗氧化酶以及改变组织形态结构从而适应外界盐度的变化。 相似文献
10.
R. Company A. Serafim M. J. Bebianno R. Cosson B. Shillito A. Fiala-Mdioni 《Marine environmental research》2004,58(2-5):377
Metals are known to influence lipid peroxidation and oxidative status of marine organisms. Hydrothermal vent mussels Bathymodiolus azoricus live in deep-sea environments with anomalous conditions, including high metal concentrations. Although B. azoricus are aerobic organisms they possess abundant methano and thioautotrophic symbiotic bacteria in the gills. The enzymatic defences (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidase (Total GPx) and selenium-dependent glutathione peroxidase (Se–GPx)) and lipid peroxidation were determined in the gills of B. azoricus exposed to Cd (0.9 μM), Cu (0.4 μM) and Hg (0.1 μM) with different times of exposure. The experiments were performed in pressurized containers at 9 ± 1 °C and 85 bars.Results show that vent mussels possess antioxidant enzymatic protection in the gills. Cd and Cu had an inhibitory effect in the enzymatic defence system, contrarily to Hg. These enzymatic systems are not completely understood in the B. azoricus, since reactive oxygen species might be produced through other processes than natural redox cycling, due to hydrogen sulphide and oxygen content present. Also the symbiotic bacteria may play an important contribution in the antioxidant protection of the gills. 相似文献
11.
为了研究不同低氧水平对菲律宾蛤仔(Ruditapes philippinarum)的影响,在实验室条件下设置溶解氧为0.5 mg/L和2.0 mg/L的低氧海水环境,以溶氧水平为7.0 mg/L的天然海水为对照组,研究了低氧胁迫对菲律宾蛤仔抗氧化酶的影响。结果表明:在低氧胁迫的时间越长的条件下,乳酸脱氢LDH和琥珀酸脱氢酶SDH的活力逐渐降低,而碱性磷酸酶AKP活力逐渐增大;对于相同的酶,对照组的酶活力高于处理组的酶活力;在溶氧DO越低的情况下,菲律宾蛤仔的死亡率越高。 相似文献
12.
13.
微粒体谷光甘肽硫转移酶(microsomal glutathione S-transferases,MGST)作为膜结合蛋白之一,具有谷光甘肽转移酶和过氧化物酶活性,在细胞及细胞器的抗氧化胁迫中扮演着重要角色,但MGST基因在紫菜(Pyropia yezoensis)中的鉴定与分析还未见报道。本文采用RACE-PCR方法首次克隆了条斑紫菜的微粒体GST基因的全长,命名为PyMGST3,同时利用生物信息学及实时定量PCR方法对该基因的序列及诱导表达特征进行了分析,并通过原核表达进一步验证了该基因的酶活性及在抗氧化胁迫中的作用。结果表明,PyMGST3基因的c DNA序列全长为681bp,其中开放阅读框长度417bp,5'-UTR长度80bp,3'-UTR长度184bp,在受到Cd~(2+)和Cu~(2+)胁迫时,上调表达;PyMGST3蛋白具有三个跨膜结构域及跨膜疏水区,与皱波角叉菜的MGST蛋白相似性最高为60%,与其它藻类的MGST蛋白的相似性较低;在大肠杆菌中表达及纯化后的PyMGST3蛋白具有谷光甘肽转移酶活性;此外,超表达PyMGST3蛋白的重组菌株提高了对抗Cd~(2+)和Cu~(2+)毒害的能力。这些结果暗示PyMGST3基因很可能在条斑紫菜遭遇重金属等引起的氧化胁迫时起到重要的保护作用。 相似文献
14.
Leão JC Geracitano LA Monserrat JM Amado LL Yunes JS 《Marine environmental research》2008,66(1):92-94
Oxidative stress induced by microcystins was evaluated in an estuarine worm, Laeonereis acuta (Nereididae). Ten organisms were exposed to lyophilized cells of a toxic Microcystisaeruginosa strain RST9501 ( approximately 2 microg/mL microcystins, MC); 10 were exposed to lyophilized cells of a nontoxic Aphanotece sp. strain RSMan92 and 10 were maintained without cyanobacterial cells. Exposure time was 48 h. The enzymatic antioxidant defenses, as well as the oxidative damage, were analyzed. Toxic and nontoxic cyanobacteria lowered catalase activity with no changes in glutathione reductase and glutathione-S-transferase activities. This may have led to toxin intracellular accumulation, which should favor oxidative stress generation, observed by the high lipid peroxide and DNA-protein crosslink levels in the group exposed to MC. 相似文献
15.
The clam Scrobicularia plana and the polychaete worm Nereis diversicolor were collected in several sites from a littoral enclosure in SW Spain. The aim of our study was to relate various biomarker responses in these species to a pollution gradient caused by untreated domestic discharges and to verify the adequacy of the selected species as sentinels in this habitat. The biomarkers selected were the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX) and DT-diaphorase (DT-D). In addition, the activities of cytochrome P450-dependent ethoxyresorufin O-deethylase (EROD) activity, the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE) were measured. Metallothionein levels were selected as biomarkers of heavy metals exposure in both species. The results suggest a different response in the water filtering organism (clam) and the sediment eater (polychaete), probably as a consequent of different pollution exposure and that samples from the “Caño Sancti-Petri” were exposed to biologically active compounds that altered some of their biochemical responses. AChE was the most sensitive biomarker in both species and N. diversicolor proved to be a more robust sentinel in this ecosystem. 相似文献
16.
为探讨海水酸化和磺胺甲恶唑环境残留对珊瑚礁区生物的影响，本文以南海珊瑚礁区关键礁栖生物大马蹄螺（Trochus niloticus） 为研究对象，探究了两种环境胁迫因素对大马蹄螺的氧化胁迫作用。分别采用两个 pH 水平 （pH 8.1、 pH 7.6） 和三个磺胺甲恶唑浓度水平 （0 ng/L、100 ng/L 和 1 000 ng/L） 单独和复合暴露 28 天，测定其对大马蹄螺鳃组织的超氧化物歧化酶 （SOD）、过氧化氢酶 （CAT） 和谷胱甘肽巯基转移酶 （GST） 活性以及谷胱甘肽 （GSH） 含量和脂质过氧化水平 （LPO） 的影响。结果发现：海水酸化和磺胺甲恶唑单独暴露能够导致大马蹄螺鳃组织出现不同程度的氧化应激现象，表现为抗氧化酶 （CAT、SOD 和 GST） 活性和谷胱甘肽含量的升高。在复合暴露条件下，大马蹄螺鳃组织的抗氧化酶（CAT、SOD 和 GST） 活性和谷胱甘肽含量均受到不同程度的抑制，同时伴随着脂质过氧化水平的显著升高。这表明短期海水酸化和磺胺甲恶唑复合暴露可导致大马蹄螺鳃组织出现氧化损伤现象，进而可能对个体存活和种群繁衍造成负面影响。 相似文献
17.
Seasonal Changes in Soluble Carbohydrates, Starch, and Energy Content in Mediterranean Seagrasses 总被引：2，自引：0，他引：2
Helmut Pirc 《Marine Ecology》1989,10(2):97-105
Abstract. In all scagrass species investigated, rhizomes were the main storage organs for soluble carbohydrate reserves, and the highest levels were found in Cymodocea nodosa (U cria ) A scherson . Sucrose was the primary soluble carbohydrate identified in Posidonia oceanica (L.) D elile , and Zostera noltii H ornem . This disaccharide was dominant in Cymodocea nodosa roots, as well as in its rhizome in winter. Myo-inositol was the main cyclitol in Zostera noltii. In Cymodocea nodosa leaves 1-chiro-inositol was the main sugar component; it was also present to a lesser extent in the roots and rhizomes. The amounts of glucose and fructose were correlated with growth to a certain extent in all species. Higher amounts of starch were stored in the rhizomes of Posidonia oceanica and Zostera noltii. The energy content of Mediterranean scagrasses was significantly higher than in tropical species. No distinct seasonal trend in energy content could be observed. 相似文献
18.
潮间带红藻海萝(Gloiopeltis furcata)对失水胁迫具有很强的耐受能力。为探索海萝周期性失水过程中的响应机制,本研究在24 h内设计了两次连续的失水-复水循环处理,测定了海萝抗氧化酶活力的变化情况。同时,利用转录组测序技术,结合荧光定量PCR方法(qRT-RCR),对海萝失水响应基因的转录表达进行了验证。结果表明:海萝转录组共组装到32681条基因。与对照组相比,处理组共表达了7161条差异表达基因(differentially expressed genes, DEGs)。KEGG分析显示, DEGs分布在代谢、环境信息加工、有机体系统、遗传信息加工、细胞进程等方面。海萝抗氧化酶活力测定发现,抗氧化能力对海萝响应失水胁迫十分重要。过氧化氢酶(CAT)、硫氧还蛋白还原酶(TrxR)、超氧化物歧化酶(SOD)参与抗氧化过程,其中CAT酶活力对海萝抵抗失水胁迫尤为重要。此外,qRT-PCR结果显示,海萝中渗透调节物质红藻糖苷合成的相关基因(GfUGPase、GfGK、GfGPDH)只对初次失水处理有正响应。而热激蛋白70基因(GfHSP70)、碳酸酐酶基因(GfCA)、MYB蛋白编码基因(GfMYB)以及谷胱甘肽S转移酶基因(GfGST)在两次失水过程中其转录水平均有上调表达,它们也参与了海萝失水响应机制。 相似文献
19.
Abstract. The vertical zonation of the hydroid fauna associated with Posidonia oceanica leaves in three different localities of the central Mediterranean reveals the presence of two distinct communities. This depth-related zonation shows patterns that are independent on the geographic area. 相似文献
20.
Abstract. The proximate composition of the various components of Posidonia oceanica is given in terms of gravimetric and energetic level and amount of plants from 2 depths at Port-Cros (Var. France). The level of proximate constituents differed little between the leaves (regardless of age) and the roots, but the rhizome contained much more soluble carbohydrate and less structural carbohydrate and ash. Because of this, the energy level in the leaves was more in terms of organic material and less in terms of total material than the energy level in the rhizome. The leaves of a P. oceanica shoot at 2 m depth in July contained 1.6 g organic material. 29.0 kJ. The weight and energy of the soluble carbohydrate in the rhizome from the base of the leaves to the 18th sheath scale decreased by ca. 40% from October to March and increased by ca. 100% from March to July. 相似文献