Peroxidase activity in avocado fruit stored at chilling temperatures

No increase in peroxidase activity was observed in ‘Fuerte’ avocado fruits which showed chilling injury symptoms as a result of storage at 0 or 2°C. Peroxidase activity in the fruit declined along with fruit softening during the ripening process. It is suggested that peroxidase acitivity in avocado fruit mesocarp has no role in the development of the chilling injury disorder appearing as dark patches on the skin of the fruit.     

Enzyme-linked immunoassay in the diagnosis of leptospirosis in domestic animals using peroxidase-conjugated protein-A

The ELISA test for detection of antibodies to Leptospirosis in domestic animals was performed using Staphylococcal protein-A coupled to peroxidase in place of antisera to IgG. Genus- and type-specific antigens were extracted with SDS technique from four pathogenic serotypes and two non-pathogenic ones, and they were identified with the aid of ELISA using specific rabbit antisera. Micro-agglutination (MA) and ELISA were compared using a total of 48 positive swine sera and a 100% agreement was obtained, since with sera from 16 dogs clinically suspected of Leptospirosis the ELISA resulted highly more sensitive and precocious than MA in detecting specific antibodies.     

光周期对大豆叶片过氧化物酶活力和同工酶谱的影响

通过研究光周期对大豆品种丹豆５号不同发育时期叶片过氧化物酶活力和同工酶谱的影响，比较了大豆初花前后光周期反应的异同．结果表明，不论在出苗至第１三出复叶展开前，第１三出复叶展开至初花期（ＲＩ）还是初花（ＲＩ）以后，短日照均加速大豆开花和（或）结实进程，并使叶片过氧化物酶活力上升．过氧化物同工酶谱因不同光周期处理而变化．作者提出，光周期对大豆初花前后发育进程的调控有相似的生长基础．供试品种从出苗至成熟阶段均对光周期敏感，而无真正的童期（ｊｕｖｅｎｉｌｅｐｈａｓｅ）．     

PEG胁迫对六倍体小黑麦幼苗SOD POD活性及MDA含量的影响

为了解水分胁迫对小黑麦叶片保护酶活性及膜脂过氧化作用的影响,以10个抗旱性不同的六倍体小黑麦为材料,用20%PEG-6000模拟干旱胁迫,研究了不同抗旱性小黑麦品种SOD,POD活性及MDA含量对水分胁迫的反应.结果表明,各品种SOD,POD活性及MDA含量均显著高于对照,但是不同品种增加幅度明显不同.其中,SOD活性胁迫系数依次为Prego>Fidelio>Prado>Szd154>Presto>Tornado>Lamberto>Moreno>Pronto>Tewo,最大是品种Prego为7.48;POD活性胁迫系数依次为Fidelio>Tornado>Presto>Prego>Szd154>Prado>Pronto>Lamberto>Moreno>Tewo,最大是Fidelio为3.19:而MDA含量胁迫系数依次为Tewo>Lamberto>Moreno>Pronto>Szd154>Fidelio>Prado>Presto>Tomado>Prego,最大是Tewo为4.71,推断在所有品种中,Prego的抗旱性最强,而Tewo抗旱性则较弱.     

山羊草谷胱甘肽S-转移酶基因家族鉴定及表达分析

谷胱甘肽S-转移酶是一种多功能蛋白酶,在植物体内参与干旱、盐、低温、重金属等多种非生物胁迫的调节;山羊草是普通小麦D染色体组的供体物种,深入挖掘山羊草中GST基因,对进一步分析六倍体小麦GST基因的功能具有重要意义。本研究利用信息生物学手段,在山羊草中共发现114条GST基因序列,分属于6个亚族;基因复制分析发现共4对基因发生了基因复制,且均为纯化选择;采用荧光定量PCR对部分GST基因在非生物胁迫下的表达分析发现,8个GST基因在响应干旱和盐胁迫时,主要在根部显著上调表达,3个GST基因在响应低温胁迫时,在根和叶中均显著上调表达,说明山羊草中的GST基因在应答非生物胁迫时,在不同组织中的表达存在着差异。     

亚硒酸钠诱导麦苗GSH-Px生物合成机理的探讨

试验表明:1.0mg·L-1的Na2SeO3可以提高麦苗地上部GSH Px的活性。试验选用抑制效果相似的转录抑制剂AMD和翻译抑制剂CHI,分别或共同与1.0mg·L-1的Na2SeO3配合处理麦苗,都能抑制由Na2SeO3诱导的GSH Px的活性,72h后其抑制效果相似,差异不显著;而不和Na2SeO3配合的处理,差异却十分显著。试验表明:Na2SeO3对GSH Px的合成的诱导除在转录或翻译水平上外,还存在其他途径。     

高灵敏电流型免疫传感器对流行性乙脑疫苗的测定

利用电沉积和多层组装技术, 将流行性乙脑疫苗抗体固定在多层聚邻苯二胺/纳米金及普鲁士蓝修饰的铂电极表面, 再用辣根过氧化物酶(HRP)代替牛血清白蛋白(BSA)封闭电极上的非特异性吸附位点, 并同时起到放大电流信号的作用, 从而制得高灵敏、高稳定电流型用于检测流行性乙脑疫苗的免疫传感器. 该传感器对乙脑疫苗检测的线性范围为6.1×10-9～8.6×10-7 lgpfu/mL. 实验结果表明, 该方法提高了抗体的固定量, 增强了传感器的灵敏度和稳定性, 且该传感器响应迅速、选择性好, 血清中常见抗原不干扰测定.     

干旱与盐胁迫下不同栽培基质碧玉兰POD活性的变化

选取树皮、泥炭、水苔、陶粒4种材料,净化处理后按8种不同配比分别对碧玉兰进行干旱胁迫和盐胁迫处理。结果表明,干旱胁迫和盐胁迫对碧玉兰体内过氧化物酶（POD）活性的影响存在差异。碧玉兰POD活性在干旱胁迫后35d保持比较平稳的上升趋势,42d时出现大幅度上升;盐胁迫后呈先上升后下降的趋势。干旱胁迫下,3／4树皮＋1／4泥炭所栽培碧玉兰POD活性上升较为稳定;盐胁迫下,1／2树皮＋1／4泥炭＋1／4陶粒所栽培碧玉兰POD活性变化相对其他栽培基质更缓和。     

香椿过氧化物酶同工酶分析

采用聚丙烯酰胺凝胶电泳法,对12个香椿品种进行过氧化物酶同工酶分析。结果表明:香椿过氧化物酶同工酶谱迁移率为0.4425～0.9038之间,有5～7条酶谱带,依染色深浅分强、中、弱三种类型;利用主成分分析和聚类分析,探讨了各品种间的亲缘关系,为香椿的品种分类提供一定的依据。     

Study on Insecticidal Activities and Effect on Three Kinds of Enzymes by 5-Aminolevulinic Acid on Oxya chinensis

Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.