马立克氏病毒1.8-kb mRNA对其上游双向启动子活性的影响

构建了针对1.8-kb mRNA基因簇潜在阅读框的RNA干扰质粒pP(1.8-kb-RNAi).将该质粒与包含其上游双向启动子的质粒pP(pp38)-CAT和pP(1.8-kb)-CAT共转染鸡胚成纤维细胞(CEF)和MDV rMd5感染的CEF(rMd5-CEF),48 h后,通过测定转染细胞裂解液中氟霉素乙酰转移酶(CAT)的活性确定1.8-kb mRNA被干扰后对双向启动子活性的影响.结果显示,利用pP(1.8-kb-RNAi)质粒干扰1.8-kb mRNA,可以使其上游双向启动子两个方向的活性均显著下降(P<0.01),其中1.8-kb mRNA方向下跌29.5%,pp38方向下跌25.0%.本研究结果证明了1.8-kb mRNA对其上游双向启动子活性有增强作用.     

Effects of Hypergravity on Salt Tolerance of Wheat Seedlings

[Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [Method] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under hypergravity of 600×g or 1 000×g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase (CAT) activity and malondialdehyde (MDA) content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group (no hypergravity or salt stress),the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group (hypergravity and salt stress) increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group,meanwhile the MDA showed an opposite result. [Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range,and hypergravity of 600×g for 4 h performed better than that of 1 000×g for 4 h.     

常山胡柚果实采后贮藏期间的生理生化变化

对常山胡柚果实贮藏期间超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、质膜相对透性的变化进行测定.结果表明,贮藏初期,果皮组织中SOD、POD、CAT活性缓慢上升,其中SOD活性在贮藏45 d时开始下降,至75 d时达最低值,然后急剧上升, POD和CAT活性在贮藏75 d时达最高,之后持续下降.果肉组织中SOD活性变化不大,总体上呈上升趋势,POD活性很低,且变化无规律,CAT活性一直呈下降趋势.果皮的质膜相对透性明显高于果肉,而且随着贮藏时间的延长而增高.     

耐冬山茶花粉储藏条件及其活力的动态变化

以山东青岛耐冬山茶花粉为试验材料,采用离体培养基法研究了花粉的萌发特性,并探讨了不同贮藏温度与贮藏时间对花粉萌发率和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响.结果表明:耐冬山茶花粉萌发的最适宜培养基为:150 g·L-1蔗糖+0.05 g·L-1硼酸+100 mg·L-1GA3+ 900 g·L-1Ca(NO3)2;花粉最佳贮藏温度为-80℃;-80℃贮藏360 d后,花粉萌发率仍达到原来的58.19％,3种保护酶活性较高,花粉抗氧化、衰老能力较强;贮藏过程中,3种保护酶活性出现最高峰值前后花粉萌发率出现大幅度下降;不同贮藏温度下,3种保护酶的作用不同,室温下POD、CAT为敏感性保护酶,4℃下SOD为敏感性保护酶,-20℃、-80℃下CAT为敏感性保护酶;3种保护酶活性对花粉萌发率的影响依次为:SOD＞ POD＞ CAT.     

离子注入对小麦三叶期3种保护酶活性的影响

以鉴54、豫农118及豫麦18号为材料,研究了不同剂量率、剂量离子注入对小麦三叶期过氧化物酶(POD)、过氧化氢酶(CAT)及超氧化物歧化酶(SOD)活性的影响.结果发现:离子注入后小麦三叶期的幼苗叶片中CAT和POD的酶活性一直高于对照,而SOD在低剂量条件下酶活高于对照,在剂量大于5.6×1017 N /cm2时酶活性低于对照.随着剂量的增加,酶活性变化趋势为先升后降,且有一定的波动性.不同剂量率间酶活有一定差异,品种间有辐射敏感性差异.     

不同温度条件下PEG引发梭梭种子对其幼苗生理生化的影响

以梭梭(H.persicum)种子为研究材料,用不同浓度的聚乙二醇(PEG)浸种处理,促其在常温(20~25℃)及低温(10~15℃)下发芽,通过对发芽率及过氧化物酶(POD)和过氧化氢酶(CAT)的活性测定。结果显示,常温25%PEG引发下,其种子萌发效果最为明显;梭梭幼苗CAT和POD在不同处理下其酶活性存在着显著的差异,说明不同处理的梭梭幼苗在抗逆性上的程度是不同的。     

不同短季棉品种衰老过程生化机理的研究

本文对中棉所16等5个短季棉品种大田栽培条件下的第10叶片和盆栽子叶附体或离体状态下某些生化变化作了研究。结果表明，中棉所16及姊妹系中427的叶绿素和可溶性蛋白质降解慢、幅度小。超氧物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性强。中棉所10的叶绿素和可溶性蛋白质降解快、幅度大。SOD、POD、CAT活性小     

茭白肉质茎膨大过程中3种保护酶的活性变化

以双季茭白浙茭3号、浙茭5号为试验材料,选择不同生长阶段的肉质茎,分别测定多酚氧化酶(PPO)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性。试验结果表明,在茭白肉质茎的膨大过程中,PPO、CAT的活性呈膨大前期下降,后期上升的趋势。PPO的活性在生长后期有明显的上升。POD的活性总体呈下降趋势,生长后期活性趋于稳定。浙茭3号、浙茭5号3种保护酶的变化趋势一致,但品种间不同酶的活性有差异。     

不同接种时间对低能N+处理水稻幼苗抗氧化物的影响

以低能N+注入处理过的水稻种子为试验材料,对其在N6培养基上不同时间接种条件下幼苗抗氧化物酶类过氧化氢酶(CAT)、过氧化物酶(POD)的活性和还原型谷胱甘肽(GSH)的含量进行了测定.结果表明,经低能N+注入处理后的水稻种子在第1天接种时,其幼苗的CAT活性最高,第5天接种时,其活性最低,与对照组均呈显著差异;而其POD活性在第1天和第5天接种时的表现正好与CAT相反;同时,GSH含量在第3天接种时与对照无显著差异,而其余处理均显著低于对照.由此说明,不同的接种时间能够对低能N+辐照过的水稻幼苗期的生理特性产生明显的生物学效应.     

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.