谷胱甘肽对小麦幼苗铜毒害的缓解作用及其与氮、硫、磷积累的相关性

采用水培法,对外源谷胱甘肽（GSH）缓解小麦幼苗铜毒害及其与氮、硫、磷等元素积累的相关性进行了研究。结果表明,Cu处理（T0组）显著抑制小麦幼苗的生长发育,导致根长、茎叶长、生物量、叶绿素和类胡萝卜素含量以及氮元素积累量下降,诱导了植株蛋白质、内源GSH含量以及硫、磷元素积累量上升。随施用外源GSH浓度的升高,GSH处理（T1、T2、T3组）的小麦幼苗茎叶长、根长、生物量,叶绿素a、b和类胡萝卜素含量、蛋白质含量先上升后下降,内源GSH含量以及氮、硫、磷等营养元素积累量持续上升;其中,T2组小麦幼苗的各项指标与T0组差异均达到显著水平（P〈0.05）,与对照组（CK）无显著差异。外源GSH促进了植株对铜离子的吸收、转运和积累,而外源和内源GSH均与铜胁迫下小麦幼苗氮、硫、磷等营养元素的积累呈极显著正相关（P〈0.01）,其中以T2处理组缓解小麦幼苗铜毒害的作用最显著。     

Resistance in the highly DDT-resistant 91-R strain of Drosophila melanogaster involves decreased penetration,increased metabolism,and direct excretion

Resistance to 4,4′-dichlorodiphenyltrichloroethane (DDT) in the 91-R strain of Drosophila melanogaster is extremely high compared to the susceptible Canton-S strain (>1500 times). In addition to enhanced oxidative detoxification, the 91-R strain also has a reduced rate of DDT penetration, increased levels of reductive and conjugative metabolism, and substantially more excretion than the Canton-S strain. Contact penetration of DDT was ∼30% less with 91-R flies, which also had significantly more cuticular hydrocarbons and a thicker, more laminated cuticle compared to Canton-S flies, possibly resulting in penetration differences. DDT was metabolized ∼1.6-fold more extensively by 91-R than Canton-S flies, resulting in dichlorodiphenyldichloroethane (DDD), two unidentified metabolites and polar conjugates being formed in significantly greater amounts. 91-R flies also excreted ∼4-fold more DDT and metabolites than Canton-S flies. Verapamil pretreatment reduced the LD₅₀ value for 91-R flies topically dosed with DDT by a factor of 10-fold, indicating that the increased excretion may involve, in part, ATP-binding cassette (ABC) transporters. In summary, DDT resistance in 91-R is polyfactorial and includes reduced penetration, increased detoxification and direct excretion.     

甲胺磷胁迫下小白菜细胞抗氧化能力的研究

以0.5g.m-2的甲胺磷喷洒小白菜后,测定7d内其体内超氧化物歧化酶(superoxidedismutase,SOD)、过氧化氢酶(cata-lase,CAT)、谷胱甘肽过氧化物酶(glutathioneperoxidase,GPX)的活性及小分子抗氧化物质谷胱甘肽(glutathione,GSH)和系统总抗氧化能力的变化规律,为食品卫生检验提供参考标准。结果表明:喷药后2～6d小白菜中SOD、CAT、GSH都高于对照;GPX的活性在2～3d低于对照,随后趋于稳态;总抗氧化能力与对照相比基本处于稳定状态;第7d各指标都又还原到与对照接近。说明甲胺磷胁迫下小白菜体内产生了氧自由基,进而诱导细胞内防御活性氧自由基毒害的物质产生,5～6d后机体恢复正常。     

不同浓度DTT或GSH预处理猪精子对ICSI效果的影响

试验采用不同浓度的DTT或GSH预处理猪精子,统计ICSI后精核解聚率、雄原核形成率及胚胎发育情况.结果表明,①精核解聚率随DTT浓度的增加而提高,6 mmol/L DTT处理组的2PN 2Pb形成率(P＜0.01)和卵裂率(P＜0.05)均高于其余各组.随着DTT浓度的增加,囊胚总细胞数呈现下降趋势.表明6 mmol/LDTT预处理精子的ICSI效果较好,但DTT在促进精核解聚的同时所产生的副作用在一定程度上影响了ICSI胚胎的后期发育;②随着GSH浓度的升高,注射卵母细胞的2PN 2Pb形成率、MPN形成率和精核解聚率均呈上升趋势.0.5 mmol/L GSH处理组的卵裂率高于其余处理组(P＜0.05)和对照组(P＜0.01),囊胚发育率显著高于对照组(P＜0.05).说明0.50 mmol/L GSH处理组的ICSI效果较好;③0.5 mmol/L GSH处理组的2PN 2Pb形成率、卵裂率和囊胚总细胞数极显著高于6 mmol/LDTT处理组(P＜0.01),两者MPN形成率差异显著(P＜0.05).表明0.5 mmol/L GSH预处理精子的ICSI效果要好于6 mmol/L DTT.     

淡紫灰链霉菌株xjy活性产物的抑菌作用及对蔬菜病害的防治效果

拮抗性微生物是生物农药的重要来源之一,加强拮抗菌的应用基础研究对于发展生物农药具有促进作用.在植物病害生物防治中拮抗性微生物主要是链霉菌属及其相关类群[1].     

GSH对低温胁迫下枇杷幼果叶绿体AsA-GSH循环代谢的影响

以3年生"早钟6号"枇杷容器苗为试材,研究不同质量浓度(100,300,500 mg·L~(-1))谷胱甘肽(GSH)处理对-3℃条件下枇杷幼果叶绿体AsA-GSH循环代谢的影响及其在抗低温胁迫中的作用.低温胁迫下枇杷幼果叶绿体抗氧化剂还原型谷胱甘肽(GSH)和抗坏血酸(AsA)含量下降,抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、单脱氢抗坏血酸还原酶(MDHAR)和脱氢抗坏血酸还原酶(DHAR)活性受到不同程度的抑制.采用100 mg·L~(-1)的GSH处理可显著提高低温胁迫下枇杷幼果叶绿体GSH,AsA含量以及APX,GR和MDHAR活性,促进AsA-GSH循环,叶绿体清除自由基的能力增强,在枇杷幼果抵抗低温胁迫中发挥作用.     

Three lignans and one coumarinolignoid with quinone reductase activity from Eurycorymbus cavaleriei

Four compounds, including one new lignan cavaol H (1), one new coumarinolignoid 5′-hydroxycleomiscosin B (4) and two known lignans (2–3) were isolated from the 95% ethanol extract of the twigs of Eurycorymbus cavaleriei. Their structures were established on the basis of various spectroscopic analyses including 1D-(¹H, ¹³C, and DEPT) and 2D-NMR (COSY, HMQC, and HMBC). The absolute stereochemistry of the two known lignans was firstly reported in this article by ¹H NMR studies on Mosher's ester derivatives. In the present study, quinone reductase induction activities of compounds 1–4 were assayed, compound 4 showed moderate quinone reductase induction with concentration to double the enzyme activity (CD) of 10.5 ± 0.8 μg/mL. Then we established LC-MS-MS analysis of glutathione (GSH) incubation with compound 4 to explain whether compound 4 induced quinone reductase through alkylating of the sulfhydryl groups of Keap1. Reconstructed selected ion chromatogram (SIC) of m/z 706 after compound 4 incubation with GSH was different from that with Tris–HCl buffer solution, which meant the quinone reductase induction activity of compound 4 attributed to alkylating the sulfhydryl groups of Keap1.     

Effect of high temperature and excessive light on glutathione content in apple peel

The present experiment was conducted to examine the changing patterns of glutathione (GSH) contents in apple peel stressed by high temperature and excessive solar radiation. By comparing the parameters of temperature and light conditions where fruits grow with the GSH contents in them, the mutual relationship was disclosed. Meanwhile, the changes of antioxidant capacity of fruits stressed at different levels were studied under artificially controlled conditions in a laboratory. Also, the effect of applying various types of exogenous substances was evaluated on endogenous GSH contents. The results indicated that within a certain range, a positive correlation was found between the stressed extents to which fruits were subject by high temperature and excessive light, and GSH contents in fruit peel. Moreover, fruits on southwest (SW) exposure contained a very significantly higher amount of GSH than those on other exposures. In laboratory experiments, it was proved that fruit GSH contents increased with temperatures within a certain range but they declined beyond a given limit. The temperature rising modes had a great influence on fruit GSH contents, and gradual temperature increase was favorable to an increase of antioxidant capability in fruit peel, thus providing a theoretical basis for exerting appropriate acclimation on fruits. It was also documented that application of four exogenous formulations could significantly increase the endogenous GSH contents, among which AsA (ascorbit acid) + BA (benzoic acid) and SA (salicylic acid) treatments exhibited better results, 33.97% and 31.81% higher than the control, respectively.     

Effect of Cadmium Stress on the Growth,Antioxidative Enzymes and Lipid Peroxidation in Two Kenaf (Hibiscus cannabinus L.) Plant Seedlings

The effects of cadmium stress on the growth, antioxidative enzymes and lipid peroxidation in two kenaf plants, Fuhong 991 and ZM412, were analysed under control (0.5-strength Hoagland's nutrient solution) or five levels of cadmium stress (0.5-strength Hoagland's nutrient solution containing different concentrations of Cd²⁺). The leaves and roots of control and cadmium-stressed plants were harvested after 3 wk. At the same Cd concentration, the Cd tolerance index of Fuhong 991 was higher than that of ZM412, indicating that Fuhong 991 may be more tolerant to Cd than ZM412. The superoxide dismutase (SOD), catalase activity (CAT) and peroxidase (POD) activities fluctuated in the leaves of the Cd-stressed plants compared to the control, whereas the glutathione reductase activity (GR) was much larger than the control for Fuhong 991, ensuring that sufficient quantities of GSH were available to respond to the cadmium stress. In comparison to the control, the dynamic tendency of the SOD, CAT and POD activities in roots of the Cd-stressed plants all increased and then declined, but the POD activity of Fuhong 991 remained nearly unchanged at all of the stress levels. The increase in the enzyme activities demonstrated that Fuhong 991 was more tolerant to cadmium than ZM 412. The lipid peroxidation was enhanced only in the leaves of Cd-stressed ZM 412. These findings indicated that antioxidative activities may play important roles in Cd-stressed Fuhong 991 and ZM 412 and that the leaf and root cell membranes of Fuhong 991 have a greater stability than those of ZM 412. For pollution monitoring purposes, the GR activity in the roots and leaves may serve as a biomarker of Cd for Fuhong 991, whereas lipid peroxidation may serve as biomarker for ZM 412.     

东北野生榛蘑氨基酸对运动性疲劳的影响

针对东北野生榛蘑氨基酸对运动性疲劳的影响进行研究。采用小鼠动物试验,通过体重测定试验表明,野生榛蘑中的氨基酸能够促进小鼠肌肉增长和增速;抗氧化试验表明,野生榛蘑中的氨基酸对小鼠运动后血清中MDA的含量影响不明显;对小鼠血清中T-SOD和GSH-Px的活性有提高作用,能够有效清除运动过程中产生的超氧阴离子和过氧化氢等自由基,缓解肌肉疲劳,减轻运动性疲劳的产生。