花生褐斑病菌侵染对不同抗性花生活氧代谢及防御酶的影响

开展了3个不同抗性花生品种经花生褐斑病菌(Cercospora arachidicola Hori)胁迫后O2-、MDA含量和防御酶系含量变化的测定,分析其与品种抗病性的相关性。结果表明,供试花生品种接种褐斑病菌1~15 d内,O2-和MDA含量均呈现先升后降的趋势。对O2-含量而言,粤油7号9 d达到最大值,花育20号7 d达到最大值,鲁花11号5 d达到最大值;对MDA含量而言,粤油7号9 d达到最大值,花育20号9 d达到最大值,鲁花11号13 d达到最大值。接种病菌后叶片中CAT、SOD、POD、PAL和PPO的含量对比分析表明,鲁花11号最高,花育20号次之,粤油7号最低;3种花生品种受侵染后病情指数与防御酶含量均呈负相关,且SOD及PAL含量在抗病品种和感病品种间存在显著差异。表明花生褐斑病菌侵染后,叶片内氧阴离子及MDA暴发时间和含量变化与花生品种抗性密切相关,抗性越强的花生品种应答时间越迅速,叶片细胞遭受破坏越小,细胞功能丧失越少;不同花生品种对褐斑病抗性水平存在差异,褐斑病菌胁迫可引起花生叶片防御酶活性及抗氧化物质含量变化,且抗性越强的花生品种防御酶含量越高;SOD和PAL含量可作为鉴定花生对褐斑病抗性的生理生化指标。

Effects of Nitric Oxide on the Germination of Wheat Seeds and Its Reactive Oxygen Species Metabolisms Under Osmotic Stress

Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).

Effects of β-Amino Butyric Acid Induced Rice Blast Resistance on Reactive Oxygen Metabolism

[Objective] This study was to understand the effects of β-Amino butyric acid(abbreviated as BABA) induced rice blast resistance on reactive oxygen metabolism. [Method] Using the cultivar Chaochan 2 that is highly susceptible to disease as experimental material, the changes of catalase(CAT), and superoxide dismutase(SOD) and MDA activities in rice treated by BABA were investigated. [Result] In rice plants treated by BABA, the activities of CAT and SOD increased, meanwhile the MDA content also rose to some extent, resulting in the disease resistance to rice blast. [Conclusion] By influencing reactive oxygen metabolism, BABA endows rice plants with resistance to rice blast. BABA is safe to environment and has highly resistance-inducing capacity, it could be generalized in production.

Indices Related to the Resistance of Yuluxiang Pear to Stresses

To clarify the mechanism for slowing down vegetative growth to reduce withered floral buds occurring in Yuluxiang pear, the length and diameter of the new shoots, the activities of antioxidant enzymes and malondialdehyde （MDA） content in terminal buds of short shoots in a withered bud-occurring orchard in Wei County, Hebei Province and a normal bud-growing orchard of Wei County, and a normal bud-growing orchard in Taigu County, Shanxi Province were measured and com- pared. The results showed that the increases in the length and diameter of new shoots in the withered bud-occurring orchard were very significantly higher than those in the two normal bud-growing orchards, and the shoots in the withered bud- occurring orchard stopped growing later than in the two normal bud-growing or- chards. During the period of floral bud differentiation, the activities of superoxide dis- mutase （SOD）, catalase （CAT）, peroxidase （POD） and the content of MDA in the two normal bud-growing orchards all increased at first and decreased subsequently. But in the withered bud-occurring orchard, the activities of both SOD and POD gradually decreased during the period of floral bud differentiation, while the activity of CAT and the content of MDA increased at first and decreased subsequently. Withered floral buds had significantly lower activities of SOD, CAT and POD, but significantly higher content of MDA than normal buds. The results suggested that vigorous vegetative growth may lead to the occurrence of withered floral buds in Yuluxiang pear; in addition, the occurrence of withered floral buds in Yuluxiang pear may also be associated with the activities of SOD, CAT and POD.

Serum levels of soluble Fas, nitric oxide and cytokines in acute decompensated cirrhotic patients

AIM： To evaluate plasma levels of nitrite/nitrate （NOx）, soluble Pas （spas） antigen, tumor necrosis factor alpha （TNF-α） and interleukin-6 （IL-6） in patients with compensated and acute decompensated cirrhosis and to evaluate mediators causing acute decompensation in liver cirrhosis, METHODS： This prospective study was conducted in the medical intensive care unit of an academic tertiary center, Fifty-five patients with acute decompensation （gastrointestinal hemorrhage, encephalopathy, hydropic decompensation） and twenty-five patients with compensated liver drrhosis were included, Blood samples were taken for analyses of spas, Nox, IL-6, TNF-α, Liver enzymes and kidney functions were also tested, RESULTS： In patients with acute decompensation, plasma spas levels were higher than in non-decompensated patients （15305 ± 4646 vs 12458± 4322 pg/mL, P 〈 0.05）. This was also true for the subgroup of patients with alcoholic liver cirrhosis （P 〈 0.05）. The other mediators were not different and none of the parameters predicted survival, except for ALT （alanine-aminotransferase）. In patients with portal-hypertension-induced acute hemorrhage, NOx levels were significantly lower than in patients with other forms of decompensation （70.8 ± 48.3 vs 112.9 ± 74.9 pg/mL, P 〈 0.05）. When NOx levels were normalized to creatinine levels, the difference disappeared. IL-6, TNF-α and spas were not different between bleeders and non-bleeders. In decompensated patients spas, IL-6 and NOx levels correlated positively with creatinine levels, while IL-6 levels were dependent on Child class. CONCLUSION： In acute decompensated cirrhotic patients sPas is increased, suggesting a role of apoptosis in this process and patients with acute bleeding have lower NOx levels, However, in this acute complex clinical situation, kidney function seems to have a predominant influence on mediator levels,

Effects of Plant Extracts with Antioxidant Activities on Male Mule Ducks＇ Performance

Plant extracts with antioxidant activities have effect on male mule ducks performance, and livestock animals have a strong metabolism activity, due to their high production requirements. It can lead to oxidative stress disorders; deteriorate growth performance and even their health. The objective of this study was to assess the effect of a mixture of active ingredients of plant extracts, known for their antioxidant and anti-inflammatory properties, on performances of mule ducks, in rearing and force-feeding period. Then 3,200 day-old mule ducks （MMGxPKL） were separated in 2 groups （negative control and treatment = EL） ×4 replicates per group for the rearing period. Each group received the same feeding program. EL group was supplemented, until the force-feeding period, with a mixture of actives from plants incorporated at 0.5% in the complete feed. At 84 days, the live weight and the feed consumption were measured for each treatment. Blood samples were also taken to measure the activity of two antioxidant enzymes： SOD （superoxide dismutase） and GPx （glutathione peroxidase）. For force-feeding, the ducks were separated among 3 farmers during 12 days. At slaughter, individual measures of breast and liver were conducted. At 84 days, mean live weight for EL group was improved by 3.7% （p 〈 0.001）. Feed conversion ratio was also improved （4.50 versus 4.62）. At slaughter, breast weight was higher for EL group （p 〈 0.01）. A high variability in the results of the activities of antioxidant enzymes was obtained. A decrease in SOD activity in erythrocytes was observed for the EL group （p 〈 0.05）. The results showed that the actives assessed in this study, distributed to ducks during the rearing period, had a beneficial effect on growth performance over that period. The mechanisms of endogenous antioxidant system and inflammatory responses remain to be elucidated.

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.

Role of vanadyl acetylacetonate-induced elevation of reactive oxygen species in the regulation of lipolysis and glucose metabolism in 3T3L1 adipocytes

In the present study, we investigated the role of reactive oxygen species（ROS） elevation induced by an anti-diabetic vanadium compound, vanadyl acetylacetonate（VO（acac）2）, in the regulation of lipolysis and glucose metabolism using differentiated 3T3L1 adipocytes as a model system. By confocal laser scanning microscopy, we found that VO（acac）2 induced ROS generation under high glucose stimulation, and the pretreatment of NADPH oxidase inhibitors could significantly reduce the elevated ROS level. Meanwhile, the decreased phosphorylated levels of AKT and the two key modulators of lipolysis（HSL and perilipin） were observed by western blot analysis. We also found that the contents of glycerol release were further reduced as well. In addition, the levels of key regulatory proteins, AS160 and GSK3β, in glucose metabolism pathway were correspondingly reduced. These findings demonstrated that ROS induced by vanadium compounds could act as a metabolic signal to activate AKT pathway to inhibit lipolysis and promote glucose transport and glycogen synthesis rather than by direct action by themselves. Our study contributed to elucidate the anti-diabetic effects of vanadium compounds and provided a theoretical basis for the further development of new vanadium complexes in the prevention and therapeutics of diabetes.

Effects of elevated ozone and nitrogen addition on leaf nitrogen metabolism in poplar

Aims Ozone(O_(3))pollution and nitrogen(N)deposition/fertilization often simultaneously affect plant growth.However,research of their interactive effects on leaf N metabolism is still scarce.We investigated their interactive effects,aiming to better understand plant N metabolism processes and biogeochemical cycles under high 03 pollution and N deposition/fertilization.Methods Poplar saplings were exposed to two O_(3)levels(NF,non-filtered ambient air;NF60,NF+60 ppb O_(3))and four N treatments(NO,no N added;N50,NO+50 kg N ha^(-1)yr^(-1);N100,NO+100 kg N ha^(-1)yr^(-1);N200,NO+200 kg N ha^(-1)yr^(-1)in open-top chambers for 95 days.The indicators related to leaf N metabolism were analyzed,including the activities of N-metabolizing enzymes and the contents of total N,NO_(3)^(-)-N,NH_(4)^(+)-N,total amino acid(TAA)and total soluble protein(TSP)in the leaves.Important Findings NF60 stimulated the activities of nitrate reductase(NR)by 47.2%at August relative to NF,and stimulated glutamine synthetase(GS)by 57.3%when averaged across all N treatments and sampling times.In contrast,O_(3)did not significantly affect TSP and even reduced TAA content in August.Relative to NO,N200 significantly increased light-saturated rate of CO_(2)assimilation(Asat)by 24%,and increased total N content by 70.3%and 43.3%in August and September,respectively,while it reduced photosynthetic N-use efficiency by 26.1%in August.These results suggest that the increase in Asat and total N content are uncoupled,and that the surplus N is not used to optimize the capacity for carbon assimilation under high N treatment.Simultaneously,high N treatment significantly promoted leaf N metabolism by increasing NO_(3)^(-)-N contents,NH_(4)^(+)-N contents,TAA contents and the activities of NR and GS.There was no significant interaction between O_(3)and N for all variables.

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