玉米大斑病菌Stga-2及其启动子的克隆与基因表达分析

【目的】克隆玉米大斑病菌(Setosphaeria turcica)Gα亚基(Heterotrimeric Gproteinalpha subunit)基因及其启动子,并对其进行异源表达,为深入研究Gα基因的表达规律、基因功能和编码蛋白的特性奠定基础。【方法】首先通过简并引物PCR法获得Gα基因的同源片段,再利用Genome walking技术克隆片段的5′端和3′端侧翼序列,最后采用RT-PCR法扩增基因全长,并对基因结构和上游调控元件进行生物信息学分析。同时,利用pET原核表达系统获得基因的编码产物。【结果】获得1个玉米大斑病菌Gα基因—Stga-2的全长序列及其上游部分启动子区,并利用pET原核表达系统对Stga-2成功进行了异源表达。生物信息学分析表明,Stga-2全长1318bp,由4个内含子和5个外显子组成,编码产物包含356个氨基酸残基。在347bp的上游侧翼序列中未发现典型的TATA-box及CAAT-box,但在起始密码子上游30bp处发现了转录起始子特征序列及位于其上游能够起始真菌基因转录的C+T丰富区域,同时还有转录因子Sp1的识别位点、CCA基序(CCAmotif)及CCG重复基序(CCG repeats)等顺式作用元件。【结论】玉米大斑病菌Stga-2及其启动子的成功克隆与表达进一步丰富了植物病原真菌的生物信息学资源,为深入了解植物病原真菌信号转导途径奠定了基础。     

好气和淹水处理间苏南水稻土有机碳矿化量差异的变化特征#br#

 【目的】探讨好气与淹水处理间水稻土有机碳矿化量差异的变化特征。【方法】采集江苏省常熟市全市范围的代表性水稻土样品并布置室内好气与淹水处理的恒温培育试验,观测土壤有机碳矿化的动态过程及矿化量变化,比较分析不同水分状况处理的土壤有机碳矿化量差异及形成机制。【结果】培养过程中不同水分状况处理下土壤有机碳日均矿化量变化趋势有显著差异,好气处理下培养前期迅速下降,而淹水处理下则迅速升高,并均在培养10 d后趋于稳定;好气与淹水处理间有机碳日均矿化量差异主要表现在培养前期,随培养时间延长而不断减小,以致培养后期差异不明显。好气处理下土壤的基础呼吸强度、有机碳日均矿化量和累计矿化量分别是淹水处理的2.26—19.11、0.96—2.41、0.96—2.41倍。统计分析表明,土壤中微生物生物量碳、氮含量越高则好气与淹水处理间呼吸强度差异越大,而若土壤中微生物生物量氮、水溶性有机碳含量越高则好气与淹水处理间土壤有机碳日均矿化量差异越大。【结论】淹水处理造成土壤微生物活性降低是导致土壤呼吸强度下降的主要原因,而在整个培养过程中土壤有机碳矿化量的变化还与水溶性有机碳含量有关。     

添加纳米碳缓释肥料对超级杂交稻产量和氮肥利用率的影响

在大田条件下,研究了添加纳米碳的缓释肥料对超级杂交中稻Y两优1号的产量、氮肥利用率及田面水总氮含量的影响.结果表明,与不添加纳米碳处理相比,添加纳米碳的金正大缓释尿素和添加纳米碳的史丹利缓释复合肥均能促进水稻分蘖的形成,增加孕穗期叶绿素含量,增加干物质累积量、有效穗、每穗实粒数,从而增加稻谷产量,提高氮肥利用率,并能降低田面水中总氮含量,减少氮肥造成的水环境污染.     

新疆甜菜组织培养及植株再生研究

[目的]以新疆的两个甜菜品系为研究对象,对培养基激素及浓度配比、外植体的选择及两个基因型的再生能力进行了初步的比较分析,以期建立起适合新疆甜菜品种(系)的组织培养体系.[方法]对不同的灭菌方式、培养基激素组合、不同外植体再生能力、不同基因型甜菜再生能力进行比较.[结果]分别对影响甜菜组织培养及植株再生体系的各个因素进行比较后建立了适合新疆甜菜的组织培养及植株再生体系.[结论]确定采用破除甜菜种壳进行灭菌处理的方法灭菌效果最明显.通过筛选,确定了甜菜叶柄再生的最适培养基激素配比,为MS+6-BA 1.0 mg/L,IAA 0.3 mg/L.对不同外植体再生能力的比较分析发现,叶柄的再生能力高于其他外植体,是较为理想的外植体来源.新甜486与413两种基因型的再生能力无明显差异.     

体外产气法评定青海省豌豆的营养价值

试验选用3头安装永久性瘤胃瘘管的4岁大通牦牛为瘤胃液固定供给动物,在相同饲养管理条件下,应用人工瘤胃(体外产气法) 技术评定了熟化后豌豆和生豌豆的营养价值 ,研究了青海当地精饲料在牦牛瘤胃中的动态发酵情况,为充分利用青海省当地精饲料,制定高寒地区放牧家畜的补饲措施提供参考.     

小花假泽兰的抑菌活性成分研究

为研究小花假泽兰的抑菌活性成分,采用活性跟踪法对小花假泽兰的全株乙醇提取物进行分离,并利用现代波谱技术(IR、1H-NMR和13C-NMR)对已分离的化合物进行结构鉴定.结果表明:从小花假泽兰中分离出4种具有抑菌活性的化合物,分别为豆甾醇、去氧薇甘菊内酯、二氢薇甘菊内酯和β-谷甾醇.采用生长速率法和孢子萌发法测定其中2种化合物(去氧薇甘菊内酯和二氢薇甘菊内酯)对8种重要植物病原菌的抑制作用.结果表明:这2种化合物对小麦纹枯病菌、辣椒疫霉病菌和棉花立枯病菌的菌丝生长抑制作用较强,100mg·L-1剂量下抑制率均在90%以上;对小麦纹枯病菌的有效抑制中浓度(EC50)分别为5.61和18.24mg·L-1;对辣椒疫霉病菌的EC50分别为13.88和12.84mg·L-1;对番茄灰霉病菌孢子萌发的EC50分别为10.49和34.68mg·L-1;对玉米大斑病菌孢子萌发的EC50分别为48.79和75.47mg·L-1.这2种化合物对农业植物病原菌的抑菌活性均为首次报道.     

Effects of Cinnamon Acid on Respiratory Rate and Its Related Enzymes Activity in Roots of Seedlings of Malus hupehensis Rehd

This paper studied the effects of cinnamon acid treatments on the respiratory rate and related enzymes activity in the seedling roots of Malus hupehensis Rehd.It would provide information for understanding the mechanisms of inhibition damage caused by continuous cultivation of apple tree.20 mL of solution containing different concentrations of cinnamon acid was added into container with the tested seedlings.After treatment,the samples were taken periodically and the respiratory rates were measured by OXY-LAB oxygen electrodes under 25°C stable temperature and then the activities of related enzymes were measured.The rates of total respiration and other 2 pathways [tricarboxylic acid cycle （TCA） and pentose phosphate pathway （PPP）] appeared initially an increasing treads and late （on the 3rd d） began to decline.However,they again appeared an increase trend at the end period,on the contrast,the respiratory rate of embden-meyer- hot-parnas （EMP） pathway appeared a stead decline tread but it had a recover on the last day.The respiratory rate of total and 3 pathways were decreased under 125 mg kg-1 （soil）.The dynamic trends of the enzymes activities of pyrophosphate-dependent phosphofructokinase （PFK）,glucose-6-phosphate dehydrogenase （G-6-PDH） and malate dehydrogenase （MDH） showed similarly.In conclusion,treatments of certain concentration of cinnamon acid would inhibit the respiratory rate and related enzymes activity of roots of M.hupehensis Rehd.And the inhibition degrees were positively related with concentration of cinnamon acid treatments.     

Effects of Microtubule Polymerization Inhibitor on the Hypersensitive Response of Wheat Induced by the Non-Host Pathogen Sphaerotheca fuliginea

The plant cytoskeleton is a highly dynamic and versatile intracellular scaffold composed of microtubules and microfilaments, serving a multiplicity of functions in plant cells. To reveal the relationship between the cytoskeleton in wheat （Triticum aestivum L.） cv. Suwon 11 attacked by the non-host pathogen Sphaerotheca fuliginea and the initiation of the hypersensitive response, the microtubule inhibitor oryzalin was injected into the wheat leaves immediately prior to inoculation. The incidence of hypersensitive cell death was significantly lower than that in water-treated control. In addition, the occurrence of hypersensitive cell death was also delayed and S. fuliginea was able to penetrate and form haustoria in epidermal tissues of wheat. All the results above indicated that hypersensitive cell death was associated with depolymerisation of microtubules, suggesting that microtubules might play an important role in the expression of non-host resistance of wheat.     

降温方法对鸭梨采后种子转色及膜透性的影响

为了了解鸭梨采后种子生理及转色与鸭梨果实褐变的关系,研究了降温方法对不同采收成熟度鸭梨种子转色和细胞膜透性的影响。结果表明:随着采收成熟度的提高和贮藏期的延长,鸭梨种子颜色逐渐加深,转色指数增加;采后早采鸭梨种子PPO活性和细胞膜渗透性最高,中采果次之,晚采果最低,较高的PPO活性导致早采果种子颜色变化最大;缓慢降温较好地抑制了鸭梨种子转色指数、PPO活性和细胞膜渗透率的升高,而且对早采果种子的影响更为明显。     

核桃仁种皮中多酚的提取工艺研究

核桃仁种皮中含有抗氧化性的多酚类物质,为探讨乙醇浓度、料液比、提取时间、提取温度对核桃仁种皮中多酚提取效果的影响,试验运用正交设计对核桃仁种皮中多酚的提取条件进行了优化。确定最佳工艺条件为:60%的乙醇,料液比为1∶8,提取时间30 min,提取温度55℃,核桃仁种皮的多酚粗提得率为5.71 mg.g-1。