重金属胁迫对醉马草生长及生理生化指标的影响

本研究通过比较不同浓度的Mn、Zn和Fe胁迫下醉马草(Achnatherum inebrians)的形态及生理生化指标,探讨醉马草对Mn、Zn和Fe的耐受性。结果表明,随着Mn、Zn和Fe胁迫浓度的增大,醉马草地上生物量积累、株高和分蘖数均显著降低(P【0.05),而脯氨酸(Pro)含量和丙二醛(MDA)含量显著升高(P【0.05)。Mn胁迫下,醉马草幼苗体内的过氧化物酶(POD)活性随着处理浓度的增加而显著(P【0.05)增加;过氧化氢酶(CAT)和超氧化物歧化酶(SOD)在Mn处理0.01~2.5mmol·L-1浓度范围内呈显著(P【0.05)上升的趋势,在Mn处理2.5~7.5 mmol·L-1浓度范围内呈显著(P【0.05)下降的趋势。Zn胁迫下,POD活性在Zn处理7.0mmol·L-1时达到最大,SOD活性在Zn处理14.0mmol·L-1时达到最大,均与其他处理差异显著(P【0.05);CAT活性随着Zn处理浓度的增大而显著(P【0.05)升高。Fe胁迫下,POD活性随着处理浓度的增加而显著(P【0.05)增加;CAT和SOD活性均在Fe处理6.0mmol·L-1时达到最大,并与其他处理差异显著(P【0.05)。综上所述,重金属胁迫对醉马草幼苗生长有一定的抑制作用,同时对其生理生化指标也产生影响。

Study on Anti-oxidation and Inhibitory Effect on Nonenzymatic Glycation Reaction of Fermentation Extract from Biotransformation of Ginkgo biloba L. (EGB) by Hericium erinaceus

[ Objective] In order to study the anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of EGB fermentation extraction biotransformed by Hericium erinaceus. [ Method ] The free radical scavenging ability and reducing capacity of DPPH as well as inhibitory rate of nonenzymatic glycation reaction were measured targets for comparing changes of anti-oxidation and inhibitory effect on nonenzymatic glycation reaction of fermentation lyophilizer and fermentation extraction before and after EGB fermention adsorbed by AB-8 macroporous resin. The EGB fermention was biotransformed by Hericium erinaceus. [ Result ] After adsorbed by AB-8 macroporous resin, the bioactive matters were concentrated and separated. The free radical scavenging rate, reducing capacity and inhibitory rate of nonenzymatic glycation reaction were increased significantly after adsorbed by AB-8 macroporous resin. [ Conclusion] AB-8 macroporous resin could be used for preliminary concentration of EGB fermentation which was biotransformed by Hericium erinaceus.

Advances in Melatonin and Its Functions in Plants

Abstract Melatonin （N-acetyi-5-methoxytryptamine） is a well-known animal hormone, which is synthesized and secreted by pineal gland and takes part in the regulation of circadian rhythm in animals. At present it has been observed that melatonin is widely existed in higher plants while there have no enough studies on functions of melatonin in plants. Researches have already indicated that the possible functions of melatonin in plants include regulating photoperiod, participating in growth regulation, clearing active oxygen, and promoting activity of antioxidase. General reviews upon functions of melatonin in plants are made upon experiments in recent years. We fo-cus on the demonstrated and predicted biological functions of melatonin in plants to bring researchers up to date on this field. The weakness in present studies and the main research directions are also pointed out.

Physiological characteristics of Ficus tikoua under antimony stress

A greenhouse culture experiment was used to evaluate the effects of antimony(Sb)stress on Ficus tikoua(F.tikoua).Theresults showed that the growth of F.tikoua leaves was significantly inhibited when Sb concentration was higher than30μmol/L,andno significantly inhibitory effect of Sb on the roots and stems of F.tikoua was found in all the treatments,implying that leaves weremore sensitive to Sb toxicity than roots and stems.Antimony concentration in the roots was higher than that in the stems and leaves.To reduce reactive oxygen species(ROS)level in the F.tikoua,the activities of superoxide dismutase(SOD),peroxidase(POD)andcatalase(CAT)increased with Sb treatments,but the SOD and CAT were more early active than POD.Although the decrease ofchlorophyll content with high Sb treatments(450μmol/L)was observed at the end of the experiments,the positive impact onchlorophyll content was observed with all the Sb treatments at the early period.No significant difference of the maximum quantumefficiency of PSII and quantum yield of PSII electron transport values with different Sb treatments was observed at the end of thisexperiment,suggesting that the photosynthesis was not inhibited with Sb concentration below450μmol/L.The results implied acertain tolerance to Sb stress for F.tikoua.This meets the essential condition for utilization in Sb contamination environments.

Science Letters:Alterations in seedling vigour and antioxidant enzyme activities in Catharanthus roseus under seed priming with native diazotrophs

An experiment was conducted on Catharanthus roseus to study the effect of seed treatments with native diazotrophs on its seedling growth and antioxidant enzyme activities. The treatments had significant influence on various seedling parameters. There is no significant influence on dry matter production with the diazotrophs, Azospirillum and Azotobacter. However, the vital seedling parameters such as germination percentage and vigour index were improved. Azotobacter treatment influenced maximum of 50% germination, whereas Azospirillum and Azotobacter were on par with C. roseus with respect to their vigour index. There was significant difference in the population of total diazotrophs. Azospirillum and Azotobacter between rhizosphere and non-rhizosphere soils of C. roseus had the same trend and were observed at various locations of the study. The activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were increased to a significant extent due to the treatment with diazotrophs.

Antioxidant enzyme activities in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense

Information regarding antioxidant enzymes in amphioxus remains lacking, and this study was carried out to examine the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense. Results show that (1) CuZn-SOD, CAT and GPX activities in the whole amphioxus B. belcheri tsing- tauense were basically at the same levels in male and female amphioxus, whereas both T-SOD and Mn-SOD activities in male amphioxus were significantly higher than that in the female (P<0.05); (2) The testis had significantly higher T-SOD and CuZn-SOD activities than the ovary (P<0.05); (3) CuZn-SOD activity was undetectable in the guts of male and female amphioxus; (4) For both male and female am- phioxus, the activities of CAT and GPX in the gonads including testis and ovary were the lowest (P<0.05) among the tissues examined; (5) The gut and gill had the same level GPX activities while the gut had a higher CAT activity; (6) There was no clear difference in CAT and GPX activities in the corresponding tissues between male and female amphioxus. The study on SOD, CAT and GPX activities in different genders and tissues of the protochordate provides data for future comparison of amphioxus antioxidant enzymes with those of invertebrates and vertebrates.

Antioxidant and isozyme features of two strains of Laminaria japonica (Phaeophyceae)

Healthy sporophytes of two gametophyte mutants of Laminariajaponica with different heat resistances： kelp 901 （901, with comparatively stronger heat-resistance） and Rongcheng No. I （RC, sensitive to heat stress）, were respectively collected during October to December 2002 from Yantai and Rongcheng Sea Farm in the Shandong Peninsula of China. The contents of some biochemical materials and antioxidant capacity were analyzed under controlled laboratory conditions to identify if there is any relation between the overall antioxidant capacity and the heat-resistance in L. japonica and to understand possible mechanism of heat-resistance. Results show that： （1） the overall antioxidant capacity in healthy sporophyte of 901, such as vitamin E, polyphenol, and ascorbic acid contents and the enzymatic activity of SOD, POD, CAT, Gpx, PPO, and PAL, were not always higher than that of RC under controlled laboratory conditions, and no significance （P〉0.05） was shown in total antioxidant capacity （T-AOC） in 901 and RC. Result suggested that the difference in antioxidant capacity was not a decisive factor for different heat-resistances in L. japonica; （2） the simultaneous assay on isozymes was carried out using vertical polyacrylamide gel electrophoresis （PAGE）. Considerable differences in peroxide （PRX）, malate dehydrogenase （MDH）, malic enzyme （ME）, polyphenol oxidase （PPO） and glutamate dehydrogenase （GDH） were obtained in 901 and RC from either the band number, relative mobility （Rf）, or staining intensity, and ME could be used as an indicator to distinguish healthy sporophyte of 901 and RC under controlled laboratory conditions.

Enhanced resistance of Portunus trituberculatus to Vibrio alginolyticus by selective breeding

We established a line (screened) of Portunus trituberculatus by selectively breeding individuals that survived from challenge with Vibrio alginolyticus, and compared the response of screened and unscreened (control) P. trituberculatus challenged with V. alginolyticus. We measured superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase, and peroxidase activity and the content of hemocyanin in the plasma and phenoloxidase activity in serum. The cumulative survival rate after 24-h challenge with V. alginolyticus was significantly higher in the screened crabs than in the unscreened crabs (P<0.05). T-SOD and PO activity were significantly lower in the screened stock than in the unscreened stock (P<0.05). POD, CAT, and ACP activity and hemocyanin content were significantly higher in the screened stock than in the unscreened stock. Our results suggest that the screened stock was more resistant to infection. Furthermore, the indices we measured may be used to evaluate the health state of P. trituberculatus.

Manila clam Venerupis philippinarum as a biomonitor to metal pollution

The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate significant biological differences in gills of white and zebra clams based on metabolic profiles and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profiles, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.

The Toxic Mechanism of High Lethality of Herbicide Butachlor in Marine Flatfish Flounder,Paralichthys olivaceus

The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill （FG） ceils exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase （SOD）, catalase （CAT） and glutathione peroxidase （GPX）. Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.

Growth and antioxidant status of oriental river prawn Macrobrachium nipponense fed with diets containing vitamin E

A feeding trial was carried out to investigate the dietary vitamin E requirement of the oriental river prawn Macrobrachium nipponense(weight of 0.3–0.4 g) and its effect role on antioxidant activity.Prawns were fed with seven levels of vitamin E(0,25,50,75,100,200,and 400 mg/kg diet) for 60 days.The results show that dietary vitamin E supplementation could significantly increased the prawn weight( P <0.05).The activity of superoxide dismutase(SOD) in the hepatopancreas was significantly higher in prawns fed with diets supplemented with ≤75 mg/kg vitamin E than in those fed with diets supplemented with 100–400 mg/kg vitamin E( P <0.05).The activity of catalase(CAT) in the hepatopancreas decreased significantly as dietary vitamin E supplementation increased( P <0.05),and no significant difference was detected in glutathione peroxidase(GSH-Px) activity between different dietary groups( P >0.05).The contents of vitamin E in the hepatopancreas and in the muscle increased with increasing dietary vitamin E.There was a linear correlation between the vitamin E level in diet and that in muscle,and between the vitamin E level in diet and that in the hepatopancreas.All the above results indicated that dietary vitamin E can be stored in the hepatopancreas and muscle and lower both the activities of SOD and CAT in the hepatopancreas,suggesting that it is a potential antioxidant in M.nipponense.Broken line analysis conducted on the weight gains of prawns in each diet group showed that the dietary vitamin E requirement for maximum growth is 94.10 mg/kg.

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats

AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.

Effects of Thallium Stress on Photosynthesis, Chlorophyll Fluorescence Parameters and Antioxidant Enzymes Activities of Coix Lacryma-jobi

Levels of T1 （Thallium） in soil from 0 （control） to 50 μg/L through 0.2, 0.5, 1 and 2.5μg/L were directly and positively correlated to levels of T1 in plant tissue, the accumulation being maximum in roots, intermediate in leaves and minimum in stems. Thallium, especially at higher concentrations, adversely affected photosynthesis （as judged based on chlorophyll fluorescence parameters）, suggesting inhibition of photo-activation of PSII （Photosystems II）, and also decreased the rate of photosynthesis, the rate of transpiration and stomatal conductivity drastically. Exposure to TI also increased the activity of CAT （Catalase） （except at 1 μg/L） and POD （Peroxidase） （except at 0.2 μg/L）, suggesting that the antioxidant systems in Coix lacryma-jobi were the main contributors of CAT and SOD （Superoxide Dismutase） and that the tolerance of C. lacryma-jobi to T1 is mainly due to this induced antioxidant machinery.

GST(phi) gene from Macrophyte Lemna minor is involved in cadmium exposure responses

Reactive oxygen species （ROS） scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms＇ response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST（phi） gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 lamol/L cadmium concentrations in comparison with other ROS scavengers. GST（phi） gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST（phi） might be involved in responding to heavy metal （cadmium） stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.

Antioxidant Defense System in Wheat （Triticum aestivum L.） Seedlings under Heat Stress and Revival Conditions

The present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes and metabolites in leaves of the wheat （Triticum aestivum L.） seedlings of heat susceptible （cv. WH 147 and HS 277） and heat tolerant （cv. WH 1021 and HW 2045） cultivars. Seven days old seedlings grown at 25 ℃ were exposed to 40 ℃ for 6 h and these seedlings were again brought to 25 ℃. The observations were recorded in the leaves of control, stressed and revived seedlings on 2nd and 4th day of revival. For the selection ofthermo-tolerant cultivars, screening of the thirty-six cultivars was done based on wilting of primary leaf and values of chlorophyll fluorescence. The MDA （malondialdehyde） and H2O2 concentration in leaves of wheat seedlings increased at the high temperature. There was enhancement in the activities of antioxidative enzymes, viz. CAT （catalase）, POX （peroxidase）, GR （glutathione reductase） and APX （ascorbate peroxidase） in leaves of the tolerant and susceptible cultivars under heat stress, however, higher percent increase was observed in tolerant cultivars. Heat stress increased the SOD （superoxide dismutase） activity in tolerant cultivars but activity declined in susceptible cultivars. On revival, the activities of the CAT, POX and GR declined in comparison to stressed seedlings but remained higher as compared to control. Ascorbate peroxidase activity remained higher on 2nd day and 4th day of revival in all the cultivars.

miR-210 over-expression enhances mesenchymal stem cell survival in an oxidative stress environment through antioxidation and c-Met pathway activation

microRNA-210(miR-210)has generally been reported to be associated with cell survival under hypoxia.However,there are few data regarding the role of miR-210 in the survival of mesenchymal stem cells(MSCs)under oxidative stress conditions.Thus,we sought to investigate whether miR-210 over-expression could protect MSCs against oxidative stress injury and what the primary mechanisms involved are.The results showed that over-expression of miR-210 significantly reduced the apoptosis of MSCs under oxidative stress,accompanied by obvious increases in cell viability and superoxide dismutase activity and remarkable decreases in malonaldehyde content and reactive oxygen species production,resulting in a noticeable reduction of apoptotic indices when compared with the control.Moreover,the above beneficial effects of miR-210 could be significantly reduced by c-Met pathway repression.Collectively,these results showed that miR-210 over-expression improved MSC survival under oxidative stress through antioxidation and c-Met pathway activation,indicating the potential development of a novel approach to enhance the efficacy of MSC-based therapy for injured myocardium.

Predator-induced physiological responses in tadpoles challenged with herbicide pollution

Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles＇ defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator （larvae of the aquatic beetle Dytiscus circumflexus）, non-lethal concentrations of herbicide （gly- phosate, 0.5 mg/L and 1.0 mg/L） or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage （TBARS） and activity of antioxidant enzymes, and immune response （via leukocyte count）. Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators （14.7% and 13.2% respec- tively） but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity

Phytochemical composition, biological potential and enzyme inhibition activity of Scandix pecten-veneris L.

Objective： Scandix pecten-veneris L. is a less studied wild edible herb and is considered an extinct plant species in many parts of the world. This study was designed to evaluate its phytochemical composition and biological potential of S. pecten-veneris L. Methods： Phytochemicals including alkaloids, fiavonoids, polyphenols, and tannins were determined in extracts of S. pecten-veneris. Antioxidant activity was determined using 2,2-diphenyl-1- picrylhydrazyl （DPPH）, while reducing power was tested by ferric reducing/antioxidant power （FRAP） assay. Antimi- crobial activity against seven bacterial and four fungal strains was evaluated using agar well diffusion assay. Enzymes inhibition study was performed for urease, phosphodiesterase-I, and catalase-II. Results： S. pecten-veneris showed moderate antiradical activity and reducing potential of hydroxyl radicals to about 20% of the initial value. The antiox- idant activity of various extracts of S. pecten-veneris showed a linear correlation with total phenolic contents in the order of water〉n-butanol〉chloroform〉ethyl acetate〉methanol extracts. S. pecten-veneris leaves showed the highest inhibitory activity against Staphylococcus aureus while the highest antifungal activity was observed against Candida albicans. The plant extract was most potent against urease enzymes but showed moderate activity against phosphodiestrase-I and carbonic anhydrase-II. Conclusions： Our data demonstrate that in addition to its culinary uses, S. pecten-veneris has good medicinal potential and hence could be used for treating some specific health ailments.