铜胁迫对弯囊苔草（ Carex dispalata）生长和生理特性的影响

用水培方法研究了弯囊苔草在不同Cu^2＋浓度（1、5、25 mg·L^-1）胁迫下的生长特性和部分生理生化指标的变化。结果表明,不同Cu^2＋浓度胁迫下,弯囊苔草正常生长,但其生长特性表现出高浓度抑制的相关性, 高浓度下没有新生根。弯囊苔草叶片3种抗氧化酶活性都随胁迫时间的延长呈先上升再下降趋势。SOD在处理的第4 d达到峰值,且活性一直显著高于对照（P＜0.05）,3种Cu^2＋浓度处理下的峰值大小顺序为5 mg·L^-1＞25 mg·L^-1＞1 mg·L^-1。POD和CAT活性在处理第7 d达到峰值,POD活性峰值大小顺序为5 mg·L^-1＞1 mg·L^-1＞25 mg·L^-1;CAT活性峰值大小顺序为25 mg·L^-1＞5 mg·L^-1＞1 mg·L^-1。丙二醛（MDA）和可溶性糖含量都是随着胁迫时间的延长而上升,处理结束时的丙二醛（MDA）（r=0.988 0）和可溶性糖含量（r=0.951 2）与Cu^2＋浓度表现出正相关性。脯氨酸（Pro）含量随胁迫时间的延长也呈先上升后下降趋势,1 mg· L^-1和5 mg·L^-1 Cu^2＋浓度处理下脯氨酸（Pro）含量在处理第4 d达到最大值,25 mg·L^-1高浓度处理下脯氨酸（Pro）含量在处理第7 d达到最大值。叶绿素在5、25 mg·L^-1 Cu^2＋浓度处理下随胁迫时间的延长呈先上升后下降的趋势,1mg·L^-1Cu^2＋处理下的叶绿素含量不断上升,实验结束时各处理下叶片的叶绿素含量与处理浓度呈负相关。结果表明弯囊苔草能通过调节体内抗氧化酶活性来增强其抗氧化胁迫能力,这为其作为铜污染水体的修复植物提供了可能。     

叶面喷施钼酸铵对橡胶树树叶抗氧化能力的影响

以橡胶树树叶为试验材料,用0 (CK)、0.01、0.02、0.04、0.08g/L浓度的钼酸铵连续喷施叶面3d,探究橡胶树乳胶中过氧化氢(H2O2)含量、树叶中H2O2和丙二醛(MDA)含量以及抗氧化酶活性.结果 表明:0.01g/L钼酸铵处理时,乳胶中H2O2含量、树叶中H2O2和MDA含量均处于最低值,且低于CK...     

蒲公英黄色素提取及抗氧化活性鉴定

从蒲公英花中提取的黄色素是一种具有一定营养价值的天然色素。研究蒲公英花中黄色素的提取方法以及抗氧化活性的测定,为蒲公英花黄色素的开发、利用提供了一定的科学依据。     

食用菌抗重金属机制研究综述

综述了汞、铅、砷、镉、铜等重金属在食用菌栽培中的富集情况,以及对食用菌生长、抗氧化系统影响的研究现状。食用菌对汞、铅、硒等重金属都表现出了不同程度的富集现象,但是随着重金属浓度增大,对食用菌生长抑制作用增大,从而降低了食用菌对重金属的富集能力。食用菌的抗氧化系统是抵抗重金属胁迫的重要机制,但目前关于这方面的研究较少。     

竹荪抗氧化物质超声波循环提取工艺

采用新兴的超声波循环萃取技术提取竹荪中抗氧化物质,以DPPH自由基清除率为抗氧化活性指标,通过单因素试验,研究提取温度、超声功率、间歇比、投料量、提取时间和乙醇浓度等6个因素对提取效果的影响.结果表明竹荪中抗氧化物质超声波循环提取的最佳条件为:提取温度40℃,超声功率600W,间歇比3∶1,投料量8％,提取时间15 min,乙醇浓度80％.     

Salicylic acid induced alleviation of oxidative stress caused by clethodim in maize (Zea mays L.) leaves

Salicylic acid is used for regulation of oxidative stress in plants subjected to unfavorable environmental conditions. Application of herbicides for the purpose of weed killing can affect not only the weeds but also the main crop as well. Many herbicides have the ability to cause oxidative stress and further degradation of cell components. In this work, SA was used to alleviate the oxidative stress caused in response to clethodim herbicide in maize leaves. The results demonstrated that, spraying of clethodim caused yellowing of leaves and sometimes browning or drying of leaf tips with high clethodim doses. Contrary, leaves showed no injuries when treated with 1 mM SA 3 days prior clethodim application. Elevated amounts of H₂O₂ and MDA were detected in clethodim treated leaves compared with control indicating ROS formation and lipid peroxidation. Excessive ROS formation led to oxidative stress which followed by degradation of membranous structures. In SA treated leaves, the contents of H₂O₂ and MDA were more or less similar to the corresponding controls. A change in the antioxidant enzymes activities due to clethodim and SA treatment was noticed. For example, the activities of POD and APX were induced while SOD and CAT were more or less reduced in response to clethodim. SA treatment prior clethodim application could induce POD but inhibit CAT. Moreover, SOD and APX activities were adjusted to be similar to those of the control. Another mechanism of SA regulation of the oxidative stress occurred through the formation of antioxidants in the form of phenolic compounds. For that, spraying SA with or without clethodim could accumulate phenolic compounds greatly. The DPPH free radical scavenging assay for leaf extracts had confirmed a change in antioxidant status. Furthermore, SA could enhance accumulation of total proteins and free amino acids in clethodim and SA treated leaves compared with the control. This work was to provide evidence for the ability of SA to regulate clethodim herbicide detoxification through regulation of the antioxidant status of maize leaf cells.     

重金属Cd及施肥对马铃薯抗氧化酶系统的影响

采用土培盆栽方法,以两个马铃薯品种克新一号和费乌瑞它为材料,研究不同浓度Cd胁迫下对马铃薯抗氧化酶系统的影响以及施肥对受Cd胁迫马铃薯的调控。结果表明,随着Cd处理浓度的提高,两个马铃薯品种叶片中SOD、CAT活性呈先上升后下降的趋势,并与对照成显著性差异。费乌瑞它马铃薯叶片中POD活性也呈先上升后下降的趋势。克新一号随着Cd处理浓度的升高,叶片POD活性呈先上升后下降再上升的趋势。随着Cd处理浓度的升高,两个品种马铃薯叶片中MDA、脯氨酸含量则成明显上升趋势。在Cd处理浓度为10mg/kg时,施用有机肥使两个品种马铃薯叶片SOD、POD活性降低,克新一号马铃薯叶片CAT活性降低。施用无机肥对两个品种马铃薯叶片SOD、CAT活性无显著性影响。与施用无机肥相比,施用有机肥对Cd胁迫马铃薯的缓解效果更明显。     

千年健中总黄酮的提取及其抗氧化活性研究

首次提取千年健中的总黄酮,并测定其抗氧化活性。对千年健中总黄酮的微波提取工艺进行了优化,最佳提取工艺为:以50%的乙醇为提取剂,微波辅助提取,功率为414 W,提取时间60 s,料液比1∶13。此条件下,黄酮提取率可达1.79%。千年健提取物具有较强的清除羟自由基能力,对羟自由基的清除率随提取物浓度的增大而增强,抗氧化活性增强。当千年健提取物浓度为100 mg/L时,对羟自由基的清除率为53.9%。同等条件下,千年健提取物对羟自由基的清除率是抗坏血酸的76.3%。     

螺旋藻小分子多肽泡沫分离法最佳工艺参数研究

采用泡沫分离法直接提取螺旋藻藻悬液上清液,并对提取液进行紫外可见光扫描和基质辅助激光解吸飞行时间串联质谱扫描,确定其主要成分为分子量在5 000 D以下的小分子多肽。根据单因素试验结果,综合考虑多肽的溶解率、回收率和提取率3种因素,选取pH=9、料液比1 g/L为最佳工艺参数。以Vc为对照,对其进行抗氧化活性研究。结果表明:提取物中小分子多肽具有还原能力,对2种自由基有不同程度清除作用。当其浓度为10 mg/mL,还原能力达到Vc的81.7%;浓度6 mg/mL,对超氧阴离子的清除率达到47.3%;浓度5 mg/mL,对羟基自由基的清除率为87.93%。     

不同脱水速率对“勐海大叶茶”种子脱水敏感性与抗氧化酶活性的影响

 以大叶茶品种“勐海大叶茶”（Camellia sinensisvar. assamicacv. Menghai Dayecha）种子为材料,研究了脱水速率对种子的脱水敏感性与抗氧化酶活性的影响。快速脱水采用活化硅胶进行脱水处理,慢速脱水采用饱和氯化钠溶液进行脱水。结果表明：“勐海大叶茶”种子对脱水敏感,种子含水量高于44%时,慢速脱水条件下,种子的脱水耐性高于快速脱水;种子含水量低于38%时,快速脱水条件下,种子脱水耐性高于慢速脱水。脱水过程中种子细胞膜系统受到了伤害,相对电导率和TBARs含量均呈上升趋势,SOD的活性总体上呈上升的趋势;CAT呈下降的趋势;慢速脱水过程中,GR和DHAR活性被激发,在一定程度上减少了脱水伤害