多枝赖草Glutathione Reductase基因克隆及胁迫表达分析

为了获得完整的谷胱甘肽还原酶基因序列,根据已克隆到的谷胱甘肽还原酶cDNA片段设计引物,利用RACE扩增获得了基因全长序列,应用Southern印迹杂交法分析基因存在状态,Northern印迹杂交法研究基因表达情况.结果表明,该基因全长1580 bp,含一个1 140 bp的开放阅读框架,编码380个氨基酸,与其它植物谷胱甘肽还原酶氨基酸序列的同源性在77%-92%之间;Southern杂交表明该基因有一个拷贝;Northern杂交表明在逆境胁迫下GR基因表达加强.

Polymorphisms of the oxidant enzymes glutathione S-transferase and glutathione reductase and their association with resistance of Plasmodium falciparum isolates to antimalarial drugs

Objective:To investigate the association between amplification of the two regulatory genes controlling glutathione(GSH) levels,glutathione reductase(PfGR) and glutathione S-transferase (PfGST) genes and sensitivity of Plasmodium falciparum(P.falciparum) isolates collected from different malaria endemic areas of Thailand to standard antimalarial drugs.Methods:A total of 70 P.falciparum isolates were collected from endemic areas of multi-drug resistance (Tak,Chantaburi and Ranong Provinces) during the year 2008-2009.The in vitro assessment of antimalarial activity of P.falciparum clones(K1- and Dd2 chloroquine resistant and 3D7- chloroquine sensitive) and isolates to chloroquine,quinine,mefloquine and arteusnate was performed based on SYBR Green modified assay.Results:68(97.14%),11(15.71%) and 28(40%) isolates respectively were classified as chloroquine-,quinine- and mefloquine-resistant isolates. With this limited number of P.falciparum isolates included in the analysis,no significant association between amplification of PfGST gene and sensitivity of the parasite to chloroquine, quinine,mefloquine and quinine was found.Based on PCR analysis,Dd2,Kl and 3D7 clones all contained only one copy of the PfGST gene.All isolates(70) also carried only one copy number of PfGST gene.There appears to be an association between amplification of PfGR gene and chloroquine resistance.The 3D7 and Dd2 clones were found to carry only one PfGR gene copy, whereas the K1 clone carried two gene copies.Conclusions:Chloroquine resistance is likely to be a consequence of multi-factors and enzymes in the GSH system may be partly involved. Larger number of parasite isolates are required to increase power of the hypothesis testing in order to confirm the involvement of both genes as well as other genes implicated in glutathione metabolism in conferring chloroquine resistance.

Artesunate Effect on Schistosome Thioredoxin Glutathione Reductase and Cytochrome c Peroxidase as New Molecular Targets in Schistosoma mansoni-infected Mice

Objective To investigate the possible effect of artesunate （ART） on schistosome thioredoxin glutathione reductase （TGR） and cytochrome c peroxidase （CcP） in Schistosoma mansoni-infected mice. Methods A total of 200 laboratory bred male Swiss albino mice were divided into 4 groups （50 mice in each group）. Group I： infected untreated group （Control group） received a vehicle of 1% sodium carbonyl methylcellulose （CMC-Na）; Group II： infected then treated with artesunate; Group III infected then treated with praziquantel, and group IV： infected then treated with artesunate then praziquantel. Adult S. mansoni worms were collected by Animal Perfusion Method, tissue egg counted, TGR, and CcP mRNA Expression were estimated of in $. mansoni adult worms by semi-quantitative rt-PCR. Results Semi-quantitative rt-PCR values revealed that treatment with artesunate caused significant decrease in expression of schistosome TGR and CcP in comparison to the untreated group. In contrast, the treatment with praziquantel did not cause significant change in expression of these genes. The results showed more reduction in total worm and female worm count in combined ART-PZQ treated group than in monotherapy treated groups by either ART or PZO, Moreover, complete disappearance （100%） of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9% and 68.4% in ART- and PZQ-treated groups. Conclusion The current study elucidated for the first time that anti-schistosomal mechanisms of artesunate is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, addition of artesunate to praziquantel could achieve complete cure outcome in treatment of schistosomiasis.

Glutathione Reductase, Liver Transaminases and Atypical Lymphocytes Count as Early Predictive Biomarkers in Diagnosis of Thrombocytopenia in Dengue Viral Infection

Objective: The aim of the study is to identify whether Atypical Lymphocyte (AL), liver transaminases, and Glutathione Reductase (GR) can be used as potential biomarkers in the assessment of severity and thrombocytopenia in dengue. Methods: A cross-sectional analytical study was carried out on diagnosed dengue patients admitted to Nawaloka Hospital, Sri Lanka. Blood samples were taken from patients (n = 50) on the day of admission, 3rd and 5th day from admission for analysis of GR, aspartate transaminase, alanine transaminase, platelets, white blood cells, and Atypical Lymphocytes (AL). Results: GR level of all three measured stages had a higher area under the curve (>88%), high sensitivity and specificity compared to liver transaminases. A significant regression model represents on admission GR and AL levels as predictive variables to platelet levels in day 03 from admission (Day 3 Platelet level = 127155.3 - 383 * GR - 0.431 * AL). Conclusion: Liver transaminases, GR, and AL% can be considered as a profile of predictive biomarkers in early diagnosis of severity of dengue infection. The degree of thrombocytopenia can be predicted using on admission GR and AL% level in acute dengue viral infection.

Glutathione Enzymes and Liver Injury in Acute Dengue Viral Infection

Identification of redox markers may be of clinical significance in the management of dengue patients. This study is to identify the association between antioxidant enzymes, hematological parameters and liver transaminases in patients with acute dengue infection. Blood samples were taken from patients on the day of admission, day 05 and 07 from admission for analysis of glutathione peroxidase (GPX), glutathione reductase (GR), aspartate transaminase (AST), alanine transaminase (ALT) and hematological parameters. AST and ALT levels were significantly elevated (p < 0.05) on day 05 in dengue patients. In contrast, GPX and GR showed significantly low levels on day 05 compared to on the day of admission and day 07. Although there was a decline in the trend of platelets towards day 05, values were not significantly different. Dengue associated with liver injury appears to peak around day 05 when the GPX and GR enzymes levels in patients were the lowest suggesting that increased viral load in the acute phase of dengue infection has initiated an antioxidant imbalance. Thus, timely investigation of antioxidant enzymes (GR and GPX) and liver transaminases around day 05 of admission may be of value in the management of patients with dengue infection similar to as seen in platelet counts.

Influence of temperature on glutathione level and glutathione-related enzyme activities of Antarctic ice microalgae Chlamydomonas sp.ICE-L

GSH system plays a role in the control of the redox balance state, anti-oxidation and protecting life from injury of ROS （ reactive oxygen species）. In present paper, the possible GSH system of Chlamydomonas sp. ICE-L has been investigated by evaluating GSH and GSH-related enzymatic responses at different temperatures using spectrophotometer methods. The results showed that the GSH system is correlated positively to low temperature, and other factors but GR are correlated negatively to high temperature. So GSH and GSH-related enzymes play an important role in the adaptation of Antarctic ice microalgae to low temperature.

The effect of high fat food on erythrocyte phospholipids, fatty acids composition and glutathione redox-system of rats with alimentary dyslipidemia

To evaluate the effects of high fat food consisted of tallow (19% of total diets) and cholesterol (2%) on modification of erythrocyte phospholipids, fatty acids composition and glutathione redox- system of male Wistar rats with alimentary dysli- pidemia. The results demonstrated that after 30 and 180 days of high-fat feed erythrocyte phos- phatidylinositol and phosphatidylcholine levels were reduced, phosphatidylserine were in-creased. Only on the 90 days of the experiment phosphatidylinositol level increased. In all grow- ups the erythrocyte 18:0 saturated fatty acids and 20:4n6, 22:4n6 polyunsaturated fatty acids (PUFA) were increased. Deficit of n3 PUFA- 20:5n3 and 22:6n3 after 90 and 180 days high fat feed promoted compensatory synthesis from 18:1n9 on 20:3n9. Erythrocyte maleic dialde-hyde increased, glutathione level decreased in all groups of rats after fed with high-fat feed. Glutathione reductase and glutathione peroxi-dase activity decreased in erythrocytes after 30 and 180 days of high-fat feed. In conclusion: high-fat diet during 30-90 days started adaptive answer in lipids of membrane and glutathione redox-system. Important mechanism of adapta-tion of a cellular membrane to high-fat diet is increase major, structuring a membrane phos-phatidylethanolamine and minor, most meta-bolic significant fractions phospholipids (phos- phatidylinositol), keeps homeostasis of 18:2n6 and 22:6n3, 20:3n9 compensatory synthesis, decrease in activity of processes lipid peroxi-dation, activation of enzymes of redox-system glutathione. But prolonging the high-fat feeding (180 days and more) formed failure compensa-tory processes (dysadaptation). It is a risk factor of developmening atherosclerosis, diabetes, steatogepatitis and other diseases.

联合检测GR、NO、IL-6对儿童病毒性心肌炎的评价

目的联合几项免疫介导的血清学指标来提高对儿童儿童病毒性心肌炎(VMC)的诊断效率,为临床提供早期的诊断价值,避免漏检对患儿引起的不良结局。方法收集泗洪医院2018年1月至2022年6月在儿科住院就诊符合条件的45例VMC病例纳入VMC组,45例单纯病毒感染患儿纳入NVMC组以及体检的50名正常儿童纳入对照组。收集研究对象一般资料,包括白细胞介素6(IL-6)、谷胱甘肽还原酶(GR)、一氧化氮(NO)以及心肌酶谱、肌钙蛋白结果。用受试者工作特征(ROC)曲线各单项指标对VMC的价值分析,并采用Logistic回归模型构建模型来预判VMC。结果VMC组的肌酸激酶同工酶(CK-MB)、天门冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)、肌钙蛋白I(cTnI)、NO、IL-6含量明显高于NVMC组和对照组,而GR含量则明显低于后两组;用各单项指标来对VMC进行ROC曲线分析,结果显示特异性最高的是cTnI的0.907,敏感性最高的是IL-6的0.912,AUC面积最大的是NO,为0.883;由cTnI、CK-MB、GR、NO、IL-6等5项指标联合建立的回归模型,当诊断界值定为0.55时,模型对VMC的AUC为0.976,敏感性为0.977,特异性为0.982,此时约登指数最大为0.959。结论用NO、GR、IL-6联合cTnI、CK-MB构建的回归模型对VMC的诊断特异性以及敏感性明显高于其他的单一指标。能够为临床医生及早的诊断儿童VMC提供有力的依据和辅助。

慢性乙型肝炎患者血清GR、FGF-21、DNMT1水平对肝纤维化程度的评估价值

目的探讨慢性乙型肝炎(CHB)患者血清谷胱甘肽还原酶(GR)、成纤维细胞生长因子21(FGF-21)、DNA甲基化转移酶1(DNMT1)水平对肝纤维化程度的评估价值。方法选取2021年5月至2023年5月于永煤集团总医院诊治的80例CHB患者为研究组,另选取同期健康体检者80例作为对照组。比较两组血清GR、FGF-21、DNMT1水平与HBV-DNA载量。依据肝纤维化程度将研究组患者分为无纤维化17例、轻度纤维化20例、中度纤维化25例、重度纤维化18例。分析血清GR、FGF-21、DNMT1水平与HBV-DNA载量、肝纤维化程度、Child-Pugh分级、炎症分级相关性。采用受试者工作特征曲线(ROC)分析血清GR、FGF-21、DNMT1对肝纤维化程度的评估价值。结果研究组血清GR、DNMT1水平高于对照组,FGF-21水平低于对照组(P<0.05);GR、DNMT1与HBV-DNA载量、肝纤维化程度、Child-Pugh分级、炎症分级呈正相关,而FGF-21与HBV-DNA载量、肝纤维化程度、Child-Pugh分级、炎症分级呈负相关(P<0.05);GR、FGF-21、DNMT1联合检测评估肝纤维化程度的AUC大于单项指标评估(P<0.05)。结论CHB患者血清GR、DNMT1水平升高,FGF-21水平降低,联合检测其水平对肝纤维化程度具有一定评估价值。

茶树谷胱甘肽还原酶基因CsGRs的克隆与表达分析

【目的】克隆谷胱甘肽还原酶基因CsGRs,研究CsGRs在茶树抵御不同逆境胁迫中的作用。【方法】在茶树转录组数据库中搜索茶树CsGRs,根据获得的基因片段,设计反转录PCR(RT-PCR)引物和RACE-PCR特异引物,从茶树中克隆CsGRs的cDNA全长序列,并利用在线生物信息学软件对其进行分析。采用实时荧光定量PCR(qRT-PCR)分析CsGRs在茶树不同组织间的表达差异及其在低温、干旱、高盐胁迫和ABA处理下的表达模式,利用分光光度计测定低温胁迫和干旱胁迫下叶片中还原型谷胱甘肽(GSH)的含量变化。【结果】RT-PCR克隆获得CsGR1的cDNA全长,其长度为1 827 bp,包含1 482 bp开放阅读框(ORF),编码493个氨基酸;RACE扩增获得712 bp和1 624 bp的5′和3′末端序列,拼接并进行RT-PCR验证后得到CsGR2序列,全长2 282 bp,包含1 698 bp ORF,编码565个氨基酸;CsGR1和CsGR2的GenBank登录号分别为KF906411和KF418080。CsGR1和CsGR2编码的蛋白质分子量分别为53.9 kD和61.0 kD,无信号肽位点,均为非分泌性蛋白。亚细胞定位预测CsGR1主要定位在细胞质等亚细胞中,无叶绿体锚定信号肽位点;CsGR2中N-端的71个氨基酸残基具有叶绿体转运信号功能,主要定位在叶绿体上。序列相似性比较显示,CsGR1与其他植物中胞质GR的相似性均在80%以上,而与叶绿体GR的相似性低于60%;CsGR2与其他叶绿体GR的相似性70%以上,与胞质GR的相似性在50%左右。二者在核酸序列和氨基酸序列水平上分别有63.4%和49.9%的相似性,且蛋白质二级结构也具有较高的相似性。系统发育树显示,CsGR1与胞质GR聚为一类,而CsGR2与叶绿体GR聚在一起,且都与葡萄的亲缘关系最近。二者均含有氧化还原二硫键活性位点、谷胱甘肽结合位点以及NADPH结合的Arg保守位点等结构域。CsGR1为胞质GR,CsGR2为双向定位在叶绿体和线粒体上的叶绿体GR。CsGR1在花和根中表达量较高,在叶片和茎中表达量低;CsGR2在叶片和茎中的表达量比在根和花中的表达量高。在短时胁迫处理24 h过程中,成熟叶片在100μmol·L-1 ABA处理后,CsGR1和CsGR2的表达均被抑制,且CsGR2的抑制作用较显著;在4℃低温胁迫下,CsGR1的表达被抑制,而CsGR2的表达随处理时间延长逐渐被诱导;250 mmol·L-1 NaCl盐胁迫抑制CsGRs的表达,但胁迫24 h时CsGR2的表达被诱导。10%(w/v)PEG胁迫处理茶树8 h,叶片中的CsGRs均被诱导表达,且在复水48 h后CsGR1的表达被显著上调;根中CsGRs的表达在处理和复水48 h过程中均被抑制。随低温胁迫时间延长,茶树叶片中的GSH含量逐渐升高;干旱胁迫也能促进GSH在叶片中的积累,在复水48 h后又恢复到处理前的水平。【结论】克隆了2个茶树CsGRs,2个基因对4℃低温、NaCl盐、10%PEG和ABA处理均具有响应。推测CsGRs在茶树抵御逆境胁迫中起作用。

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.

硒性白内障大鼠模型晶状体中GR和GSH-Px的表达

为探讨硒性白内障大鼠晶状体中谷胱甘肽过氧化物酶 (GSH Px)和谷胱甘肽还原酶 (GR)的活性调节在硒性白内障形成中的作用及调节方式 ,采用半定量RT PCR方法 ,比较正常晶状体、核中心混浊晶状体 (核白 )和完全混浊晶状体 (全白 )中GSH Px和GR的mRNA水平及酶活性的变化 .研究发现 ,核白晶状体中 2种酶的活性和mRNA水平均升高 ,其中酶活性的升高幅度小于mRNA水平 .随着白内障的发展 ,2种酶的活性和mRNA水平均逐渐下降 .至晶状体全白时 ,2种酶的活性均显著低于正常 ;全白时GR的mRNA水平降至正常 ,GSH Px的mRNA水平则仍高于正常 .结果表明 ,硒性白内障形成与细胞内GSH Px和GR的活性调节密切相关 ,GSH

冷锻炼对水稻和黄瓜幼苗SOD、GR活性及GSH、AsA含量的影响

水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）和黄瓜（Ｃｕｃｕｍ ｉｓｍ ｅｌｏ Ｌ．）幼苗在昼夜温度为１５ ℃／１０ ℃、白天光照１２ ｈ，光强为２５０ μｍ ｏｌ·ｍ － ２·ｓ－ １的条件下锻炼３ ｄ，明显地提高幼苗叶片中膜保护酶——超氧物歧化酶（ＳＯＤ）、谷胱甘肽还原酶（ＧＲ）活性和内源抗氧化剂——还原型谷胱甘肽（ＧＳＨ）、抗坏血酸（ＡｓＡ）的含量。经冷锻炼和未锻炼的幼苗移置４ ℃、光强为２５０ μｍ ｏｌ·ｍ － ２·ｓ－ １下胁迫处理２ ｄ，未锻炼苗叶片中ＳＯＤ、ＧＲ 活性和ＧＳＨ、ＡｓＡ 含量明显下降，而经冷锻炼的苗则相对比较稳定。从脂质过氧化产物——丙二醛（ＭＤＡ）含量及幼苗的存活率亦看出：冷锻炼苗具有较低的脂质过氧化水平和较高的幼苗存活率。由此认为：冷锻炼能提高水稻和黄瓜幼苗细胞膜的稳定性。

成年糖尿病大鼠重要器官组织GSH-Px、GSH和GR水平变化

目的 :探讨糖尿病对大鼠重要器官组织抗氧化水平的影响。方法 :90日龄 Wistar大鼠 2 4只 ,随机分为正常对照组 (C)、胰岛素治疗糖尿病组 (ID)和糖尿病组 (D) ,每组 8只 ,取大鼠器官组织用比色法测定 GSH-Px、GSH和 GR水平变化。结果 :D组与 C组比较大鼠心、肾、胰腺组织 GSH- Px水平升高 (P<0 .0 5或 P<0 .0 1 ) ,D组与 ID组比较肝组织 GSH- Px水平升高 ,但差异无显著性 ,脾组织 GSH- Px水平无变化 ;而大鼠心、肝、肾、胰、脾组织 GSH、 GR水平均降低 (P<0 .0 5或 P<0 .0 1 ) ;经胰岛素治疗后 ,5个器官组织中 GSH- Px、GSH和GR水平均有改善。结论 :经胰岛素治疗后 。

谷胱甘肽提高月季切花失水胁迫耐性与GR活性的关系

本研究确定了切花月季‘Sam antha’预处理采用的谷胱甘肽(GSH)及其生物合成抑制剂丁胱亚磺酰胺〔L-buth ione(S,R)su lfoxim ine,BSO〕适宜浓度,探讨了GSH和BSO预处理对花朵水势、花瓣中MDA含量、GSH含量以及GR活性等的影响。结果表明:与失水胁迫对照处理相比较,2 mmol/L GSH预处理明显提高了月季切花瓶插期间花朵水势,显著降低了花瓣中MDA含量,有效提高了花瓣中GSH含量和GR活性。2 mmol/L BSO预处理获得了理想的反证结果。结果说明,GSH对切花月季‘Sam antha’失水胁迫耐性的改善与花瓣中GR活性的提高相联系。

发状念珠藻干旱胁迫响应基因NfGR的克隆与鉴定

该研究采用PCR技术,从发状念珠藻细胞中克隆了谷胱甘肽还原酶(glutathione reductase,GR)基因,命名为NfGR,其开放阅读框长1 374bp,编码458个氨基酸,蛋白相对分子量为49.42kD,理论等电点为5.49。氨基酸序列分析表明,NfGR蛋白具有NADPH结合位点超家族(NADB-Rossmann superfamily)和吡啶氧化还原酶二聚体超家族(Pyr_redox_dim superfamily)2个结构域,与点形念珠藻(Nostoc punctiforme)的相似性达93%。系统进化树分析表明,NfGR与点形念珠藻处在同一进化枝上,亲缘关系较近。qRT-PCR表达分析表明,在不同浓度PEG-6000处理下,NfGR基因均保持上调表达,其中,PEG-6000浓度为8%时,NfGR基因的相对表达量达到峰值(32.69)。研究推测,谷胱甘肽还原酶可能参与了发状念珠藻对干旱胁迫过程的响应。

灌浆期高温对小麦旗叶中SOD和GR活性及相关基因表达量的影响

以山农23和济麦20为试验材料,研究灌浆期（花后10-20 d）高温对小麦旗叶中超氧化物歧化酶（SOD）和谷胱甘肽还原酶（GR）活性及相关基因表达量的影响。结果表明,在高温胁迫条件下,山农23的SOD活性一直显著高于对照,而济麦20的SOD活性变化呈先升高后降低的趋势。山农23中Fe-SOD和Mn-SOD表达量的变化与SOD活性的变化趋势相似,但Cu/Zn-SOD表达量的变化与SOD活性的变化趋势不同。济麦20中3个SOD基因表达量的变化均与SOD活性的变化基本一致。高温胁迫条件下两个小麦品种的GR活性均呈现先升高后降低的趋势,山农23中GR表达量的变化与GR活性的变化趋势基本一致,济麦20中GR表达量的变化早于GR活性的变化。总体来看,高温胁迫条件下山农23具有较强的抗氧化能力,Fe-SOD和Mn-SOD基因对SOD活性起主要作用,抗氧化酶相关基因对灌浆期高温胁迫的响应比酶活性更敏感。

巨尾桉EuGR1基因的克隆及其低温胁迫下的表达特性分析

本研究通过反转录PCR方法克隆了巨尾桉谷胱甘肽还原酶(Glutathione reductase,简称GR)基因,该基因定位于巨尾桉细胞质、长度为1485 bp,在NCBI申请基因注册(GenBank Accession Number KU904639)。构建了pET-EuGR1原核表达载体,酶活检测表明转化菌株GR活性较高。利用实时定量PCR分析巨尾桉EuGR1的时空表达特性,结果表明:EuGR1的表达量随着巨尾桉叶片的成熟而降低,在幼叶中表达量最大,近根部的叶片表达量最低;在巨尾桉组培苗中,EuGR1在茎中表达量最大,叶中表达量较低,根中表达量最低。通过转基因抗寒巨尾桉温室苗研究EuGR1基因在低温胁迫下的表达模式,发现常温和低温胁迫下耐寒性强的株系其EuGR1的表达量较高(如P40、P41、P52),耐寒性弱的株系其EuGR1的表达量较低(如P36、F44、F76),说明巨尾桉EuGR1的表达量与植株的抗寒能力具有相关性。随着低温胁迫时间的延长,EuGR1的表达量在36 h后出现降低趋势,表明EuGR1在桉树耐低温胁迫的前期发挥作用较大。

不结球白菜谷胱甘肽还原酶基因NhccGR1的克隆与表达分析

利用cDNA-AFLP技术,从芜菁花叶病毒(TuMV)侵染的不结球白菜(Brassica campestris ssp.chinensis Makino)幼叶中分离到1条编码谷胱甘肽还原酶的基因片段,通过电子克隆得到其cDNA全长为1 503 bp,编码501个氨基酸,命名为Nhc-cGR1。对该基因进行生物信息学分析,并利用实时定量PCR研究其在TuMV侵染和水杨酸(SA)、茉莉酸(JA)、乙烯(ET)诱导下的表达情况。结果表明:该基因作为病原相关基因参与了TuMV病害响应,并通过增加自身表达量来激活细胞内的信号转导途径,诱导各种防卫反应相关基因的表达;同时,SA和JA抑制该基因的表达,外施ET能诱导其正向表达。

柠条锦鸡儿抗坏血酸过氧化物酶基因(CkAPX)和谷胱甘肽还原酶基因(CkGR) cDNA片段的克隆及表达分析

抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)是植物体内抗坏血酸-谷胱甘肽循环系统的重要组成部分,是植物清除活性氧(ROS)的主要酶。根据前期对不同干旱地区柠条锦鸡儿叶片的转录组测序结果,克隆了2个与清除过氧化氢相关的基因:抗坏血酸过氧化物酶基因(CkAPX)和谷胱甘肽还原酶基因(CkGR)片段,长度分别为509bp和519bp。序列分析表明APX蛋白和GR蛋白在不同物种中相对保守,在已克隆APX和GR基因的物种中,柠条APX蛋白与豆科植物蒺藜苜蓿(Medicago truncatula)的亲缘关系最近,GR蛋白与豆科植物鹰嘴豆(Cicer arietinum)的亲缘关系最近。对安塞、神木和东胜的柠条叶片中的CkAPX和CkGR的表达量和酶活性分析表明,随着降雨量的减少干旱叶片中柠条CkAPX和CkGR的表达量和活性均呈上升趋势,说明此2基因在增强柠条锦鸡儿的抗旱性方面起重要作用。