硝酸钬对小鼠骨髓细胞核异常和肝脏三种抗氧化酶活力的影响

两次给小鼠腹腔注射硝酸钬溶液,相间24h,第二次注射24h后取股骨骨髓涂片,同时取肝脏检测超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活力。结果发现,在(10～40)mg/kg·bw剂量范围内,微核率和三种酶的活力随剂量的增加而升高;当剂量升至80mg/kg·bw时,三种酶活力趋于下降,但仍高于阴性对照组,而微核率增加到最大值;当剂量升至160mg/kg·bw时,微核率和酶活力均低于阴性对照组。低剂量(<40mg/kg·bw)硝酸钬溶液可促进骨髓细胞增殖,高浓度则表现出抑制作用。实验中还观察到核异常程度随剂量的增加而上升。推测低剂量钬离子通过诱导小鼠机体三种抗氧化酶活力的升高,清除部分自由基,一定程度上减轻了染色体损伤,高剂量则抑制了细胞分裂指数,又降低小鼠体内抗氧化酶活力,从而促进核异常。

RICE TRANSFORMATION WITH A PHYTOALEXIN GENE AND BIOASSAY OF THE TRANSGENIC PLANTS

Immature embryos, mature embryos and embryogenic calli of 6 rice (Oryza sativa L.) materials were transformed with particle bombardment. The plasmids pSSVstl and pVE5+ were used, both containing the phytoalexin gene from grapevine coding for stilbene synthase, but driven by 35S and its own promoter respectively. Through resistance selection for G418 (100 to 150 mg/L) or hygromycin (50 mg/L), 54 independent transgenic plants were isolated and further assessed by PCR, Southern blot and Dot blot analyses. The transgenic plants and their progenies were tested for resistance to blast ( Pyricularia oryzae ) and bacterial blight of rice ( Xanthomonas oryzae ). Preliminary results indicated that the stilbene synthase gene could enhance the resistance of transgenic plants and their progenies to both pathogens.

Influences of 5-ALA Application on Winter Oilseed Rape (Brassica napus L.) Growth before Winter

[Objective] The aim of this paper is to investigate the influences of exogenous 5-aminolevulinic acid （5-aLA） application on the growth and mechanism of winter oilseed rape （Brassica napus L.） before winter. [Method] For this purpose a split-plot experimental design with four treatments of seed soaking with 0,25,50 and 75 mg/L ALA solution （CK,A1,A2 and A3） was carried out from October 2009 to January 2010 in order to observe the influences upon the growth and relevant physiological indexes of Zhongshuang 9. [Result] Seed soaking with ALA solution significantly promotes the growth of double-9 before winter,which is probably due to the fact that ALA application enhances its photosynthesis,absorption of nutrients,and its anti-oxidation abilities. The research also finds that ALA treatment notably increases its photosynthetic pigment contents,root activities,leaf nitrate reductase activities,soluble sugar contents,antioxidase activities,and significantly decreases malondialdehyde（MDA） content. [Conclusion] These results indicate that seed soaking with 50 mg/L ALA solution might have a potential application in increasing the productivity of winter oilseed rape in agricultural management.

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.

Protective Role of Ca Against NaCl Toxicity in Jerusalem Artichoke by Up-Regulation of Antioxidant Enzymes

The ameliorative effect of external Ca^2＋ on Jerusalem artichoke （Helianthus tuberosus L.） under salt stress was studied through biochemical and physiological analyses of Jerusalem artichoke seedlings treated with or without 10 mol L^-1 CaCl2, 150 mmol L^-1 NaCl, and/or 5 mmol L^-1 ethylene-bis（oxyethylenenitrilo）-tetraacetic acid （EGTA） for five days. Exposure to NaC1 （150 mmol L^-1） decreased growth, leaf chlorophyll content, and photosynthetic rate of Jerusalem artichoke seedlings. NaC1 treatment showed 59% and 37% higher lipid peroxidation and electrolyte leakage, respectively, than the control. The activities of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） were decreased by NaCl, indicating an impeded antioxidant defense mechanism of Jerusalem artichoke grown under salt stress. Addition of 10 mmol L^-1 CaCl2 to the salt solutions significantly decreased the damaging effect of NaC1 on growth and chlorophyll content and simultaneously restored the rate of photosynthesis almost to the level of the control. Ca^2＋ addition decreased the leaf malondialdehyde （MDA） content and electrolyte leakage from NaCl-treated seedlings by 47% and 24%, respectively, and significantly improved the activities of SOD, POD, and CAT in NaCl-treated plants. Addition of EGTA, a specific chelator of Ca2＋, decreased the growth, chlorophyll content, and photosynthesis, and increased level of MDA and electrolyte leakage from NaCl-treated plants and from the control plants. EGTA addition to the growth medium also repressed the activities of SOD, POD, and CAT in NaCl-treated and control seedlings. External Ca2＋ might protect Jerusalem artichoke against NaC1 stress by up-regulating the activities of antioxidant enzymes and thereby decreasing the oxidative stress.

Antioxidant role of heme oxygenase-1 in prehepatic portal hypertensive rats

AIM： To study the effect of bilirubin on the oxidative liver status and the activity and expression of heine oxygenase-1 （HO-1） in rat liver injury induced by prehepatic portal hypertension. METHODS： Wistar male rats, weighing 200-250 g, were divided at random into two groups： one group with prehepatic portal hypertension （PH） induced by regulated prehepatic portal vein ligation （PPVL） and the other group corresponded to sham operated rats. Portal pressure, oxidative stress parameters, antioxidant enzymes, HO-1 activity and expression and hepatic sinusoidal vasodilatation were measured. RESULTS： In PPVL rats oxidative stress was evidenced by a marked increase in thiobarbituric acid reactive substances （TBARS） content and a decrease in reduced glutathione （GSH） levels. The activities of liver antioxidant enzymes, superoxide dismutase （SOD）, catalase （CAT） and glutathione peroxidase （GSH-Px） were also diminished while activity and expression of HO-1 were enhanced. Administration of bilirubin （5μmol/kg body weight） 24 h before the end of the experiment entirely prevented all these effects. Pretreatment with Sn-protoporphyrin IX （Sn-PPIX） （100 μg/kg body weight, i.p.）, a potent inhibitor of HO, completely abolished the oxidative stress and provoked a slight decrease in liver GSH levels as well as an increase in lipid peroxidation. Besides, carbon monoxide, another heme catabolic product, induced a significant increase in sinusoidal hepatic areas in PPVL group. Pretreatment of PPVL rats with Sn-PPIX totally prevented this effect CONCLUSION： These results suggest a beneficial role of HO-1 overexpression in prehepatic portal hypertensive rats.

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.

Effect of dietary supplementation of vitamin C on growth, reactive oxygen species, and antioxidant enzyme activity of Apostichopus japonicus(Selenka) juveniles exposed to nitrite

Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.

Physiological Response of Hydrilla verticillata （I.f.） Royle Exposed to Cadmium Stress

Hydrilla verticillata （I.f.） Royle twigs were exposed to CdCI2 （50, 100, 200 and 500 BM） under continuous light for 48 hrs and the physiological parameters like photosynthetic pigment （chlorophylls a, b and carotenoids） contents, activities of antioxidative enzymes like superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POX） along with lipid peroxidation level were determined. With respect to increase in Cd concentration in the medium and exposure duration, decrease in pigment contents, and decrease in the activities of SOD, CAT and POX were found. The increased levels of lipid peroxidation indicated the prevalence of oxidative stress situation in the tissues which might be one of the reasons behind Cd induced toxicity in Hydrilla verticillata. Since there was significant decrease in the activities of key antioxidative ezymes, the study suggests that Hydrilla verticillata may not be effective for phytoremediation of cadmium in these concentration ranges.

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.

Drying temperature affects rice seed vigor via gibberellin,abscisic acid,and antioxidant enzyme metabolism

Seed vigor is a key factor affecti ng seed quality.The mechanical drying process exerts a sign ificant in fluence on rice seed vigor.The initial moisture con tent(IMC)and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying.This study aimed to determine the optimum drying temperature for rice seeds according to the IMC,and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor.Rice seeds with three different IMCs(20%,25%,and 30%)were dried to the target moisture content(14%)at four different drying temperatures.The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds.The upper limits of drying temperature for rice seeds with 20%,25%,and 30%IMCs were 45,42,and 38°C,respectively.The drying rate and seed temperature increased sign ificantly with in creasing drying temperature.The drying temperature,drying rate,and seed temperature showed extremely significant negative correlations with germination energy(GE),germination rate,germination index(Gl),and vigor index(VI).A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide(H2O2)and superoxide anions in the seeds,enhanced superoxide dismutase(SOD)and catalase(CAT)activity,and increased the abscisic acid(ABA)content.In the early stage of seed germination,the IMC and drying temperature regulated seed germination through the metabolism of H2O2,gibberellin acid(GA),ABA,and a-amylase.These results indicate that the metabolism of reactive oxygen species(ROS),antioxidant enzymes,GA,ABA,and a-amylase might be involved in the mediation of the effects of drying temperature on seed vigor.The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.

Inhalation of Roman chamomile essential oil attenuates depressive-like behaviors in Wistar Kyoto rats

The idea of aromatherapy, using essential oils, has been considered as an alternative antidepressant treatment. In the present study, we investigated the effect of Roman chamomile essential oil inhalation for two weeks on depressive-like behaviors in Wistar-Kyoto(WKY) rats. We found that inhalation of either Roman chamomile or one of its main components α-pinene,attenuated depressive-like behavior in WKY rats in the forced swim test. Using isobaric tags for relative and absolute quantitation analysis(iTRAQ), we found that inhalation of α-pinene increased expression of proteins that are involved in oxidative phosphorylation, such as cytochrome c oxidase subunit 6C-2, cytochrome c oxidase subunit 7A2, ATPase inhibitor in the hippocampus, and cytochrome c oxidase subunit 6C-2, ATP synthase subunit e, Acyl carrier protein, and Cytochrome b-c1 complex subunit 6 in the PFC(prefrontal cortex). In addition, using the quantitative real-time polymerase chain reaction technique, we confirmed an increase of parvalbumin mRNA expression in the hippocampus, which was shown to be upregulated by 2.8-fold in iTRAQ analysis, in α-pinene treated WKY rats. These findings collectively suggest the involvement of mitochondrial functions and parvalbumin-related signaling in the antidepressant effect of α-pinene inhalation.

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.