大豆class III酸性内切几丁质酶基因及其启动子表达方式

利用实时定量PCR方法,检测大豆class III 酸性内切几丁质酶基因在大豆各组织中的表达,结果显示该基因在大豆根、茎、叶中的表达活性低,而花和种子中的相对表达活性极高。利用PCR方法,克隆大豆class III 酸性内切几丁质酶基因5’端上游2000bp序列,命名为CP。在线启动子预测软件分析,结果表明CP序列中含有多种典型的种子特异表达元件和花特异表达的元件,如SEF4 motif、E-box、G-box、(CA)n、AACA、ACGT、CCAA;52-box、ntp303-box、GTGA、TACPyATbox。推测大豆class III 酸性内切几丁质酶基因启动子具有调控下游基因在花和种子中大量表达的特性。       

暗纹东方鲀线粒体COIII克隆及序列分析

克隆并测定了暗纹东方鲀线粒体基因组(m tDNA)含完整的细胞色素氧化酶亚基Ⅲ(CO III)及其下游70 bp的tRNAG ly序列。CO III基因编码框包含786个核苷酸,编码262个氨基酸的蛋白质。鱼类CO III的序列组成对A T核苷酸的偏倚程度比较低。通过暗纹东方鲀与GenBank中8个目12种鱼类的CO III序列同源性比较,显示暗纹东方鲀与这些鱼类的CO III基因具有较高的同源性。根据暗纹东方鲀与鲀目其他5种鱼的CO III基因序列所建立的进化树,与传统的分类地位相吻合。推定的tR-NA的二级结构具有典型的三叶草型结构。根据CO III序列构建的分子进化树分析,认为在采用线粒体基因序列进行分子进化分析时,应综合考虑物种遗传变异的特点。     

桂垦3号油梨贮藏保鲜技术研究

研究了广东油梨栽培品种桂垦3号的贮藏保鲜技术,结果表明:50℃下用0.1%施保功浸泡10 min可有效控制油梨贮藏病害,处理后的油梨果实在3℃下贮藏15 d后明显遭受冷害、果肉褐变且不能正常成熟软化,11℃下贮藏发生缓慢后熟,7℃下的贮藏效果介于3℃和11℃之间;50℃热水处理(5、10、15 min)和38℃热空气处理(12、24、36 h)均能不同程度减轻油梨3℃贮藏冷害.其中以热空气处理24 h对减轻油梨果实低温贮藏冷害症状最有效,贮藏15 d后无冷害症状、果实能正常成熟.     

嗜水气单胞菌Ⅲ型分泌系统ascV全长基因的克隆及其在不同菌株中的分布

根据已发表的嗜水气单胞菌Ⅲ型分泌系统（TTSS）的ascV基因保守区核苷酸序列设计合成1对引物,以国内疫苗菌株J-1的基因组为模板,通过PCR扩增得到331bp保守基因片段,将目的片段进行测序。在此基础上,分4段克隆J-1株的Ⅱscv基因并进一步拼接,全长为2166bp,同时PCR检测ascV基因在66株嗜水气单胞菌中的分布情况。测序分析发现,扩增出的J-1株ascV全长基因与嗜水气单胞菌AH-1、SSU、AH-3的同源性分别为97％、86％、86％,与杀鲑气单胞菌杀鲑亚种A449的同源性为86％,与温和气单胞菌的同源性为87％。PCR检测表明,64株能扩增出n5fV基因的目的片段,包括2株无毒菌株,而在2株有毒菌株中却未能检测到,说明TTSS在嗜水气单胞菌致病机制上的作用值得进一步探讨。     

水稻白叶枯病菌Zur和HrpG平行调控hrcC基因表达

 水稻白叶枯病菌(Xanthomonas oryzae pv. oryzae, Xoo)的III型分泌系统(Type III secretion system, T3SS)由hrp基因簇编码,其决定在寄主水稻上的致病性。hrcC是hrp基因簇中hrpA转录单元仅有的一个基因,推测编码T3SS的核心组分蛋白。在Xoo中,hrcC在致病性中的功能以及受调控的机制仍未明确。本研究构建了hrcC的缺失突变体及其功能互补子,发现hrcC缺失使Xoo丧失了在寄主水稻上的致病性以及在非寄主烟草上激发过敏反应(Hypersensitive response, HR)的能力,功能互补子能够恢复这些表型至野生型水平。启动子GUS活性的定量测定和蛋白免疫杂交试验,证明hrcC的转录表达依赖于主要的hrp调控子HrpG,而不受HrpX调控;HrpG和铁转运家族类调控子(Ferric uptake regulator family)Zur以平行独立的方式正调控hrcC基因的转录表达。异源功能互补、启动子活性和蛋白表达试验发现Xoo和水稻条斑病菌(Xanthomonas oryzae pv. oryzicola, Xoc)的hrcC基因在致病性上的功能具有互置性,以及受HrpG、HrpX和Zur的调控模式也具有相似性。这些研究为进一步解析黄单胞菌的hrp调控网络与全毒性调控网络之间的交叉提供了新的线索。     

粳型杂交水稻新组合Ⅲ优98的亲本特性及制种技术研究

根据Ⅲ优98亲本的特征特性,经过多年的深入研究和制种实践,总结出了该组合的优质高产制种技术。     

黔糖3号果蔗病害调查与病原菌鉴定初报

近年来,贵州黔糖3号果蔗生产年年发生病害,严重感病蔗田已出现绝收现象。为探讨其防治技术,项目组对黔糖3号果蔗病害进行了调查和病原菌鉴定,主要通过蔗田多处布点跟踪观察了解和感病植株病叶取样以常规植病研究法消毒后的病组织置于(PDA)培养、病原菌分离、镜检鉴定等综合分析,结果有6种病害,其中以虎斑病、褐条病、黄斑(点)病三种危害较重,并详细介绍了6种病害在植株上的田间表现症状、病原菌特征及发生特点,同时结合生产实际提出了五条相应的防治对策。     

Characterization of Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease in southern Thailand

Vibrio parahaemolyticus was isolated from shrimp of five farms located in the Pattani and Songkhla provinces of southern Thailand. Using a PCR method targeted to the unique DNA sequences derived from the plasmid (AP2 primers) and the toxin gene (AP3 primers) of V. parahaemolyticus that caused acute hepatopancreatic necrosis disease (AHPND), a total of 33 of 108 isolates were positive. In contrast, all 63 and 66 isolates of clinical and environmental V. parahaemolyticus, respectively, obtained previously from 2008 to 2014 from the same area were negative. This implied that these strains were likely to be the cause of the outbreak of AHPND in this area. Intestinal samples proved to be a better source for the isolation of V. parahaemolyticus AHPND than the hepatopancreas. All isolates were investigated for haemolytic activity, virulence genes, serotypes, genotypes and antibiotic susceptibility. All the AHPND isolates had a unique O antigen, but small variations of the K antigens were detected from different farms. In addition, the DNA profiles of V. parahaemolyticus AHPND isolates were similar, but distinct from those clinical and environmental isolates. It is postulated that the causative agent of AHPND might have originated from one clone and then slightly different serotypes subsequently developed.     

Insecticidal 2-hydroxy-3-alkyl-1,4-naphthoquinones: correlation of inhibition of ubiquinol cytochrome c oxidoreductase (complex III) with insecticidal activity

The insecticidal and in vitro activities of four homologous series of 2-hydroxy and acetoxy-3-substituted-1,4-naphthoquinones have been measured and correlated with their (Log) octanol/water partition coefficients (Log Ko/w). In vitro activity against mitochondrial complex III was only exhibited by 2-hydroxy-3-alkyl-1,4-naphthoquinones, indicating that the 2-acetoxy compounds act as proinsecticides. Good correlation was observed between in vivo activity against the two-spotted spider mite, Tetranychus urticae and inhibition of complex III isolated from blowfly flight muscle. Both hydroxy and acetoxy analogues of individual compounds exhibited similar levels of in vivo activity with optimum activity for analogues with Log Ko/w values of 7-8. In contrast, the acetoxy derivatives showed superior in vivo activity against the tobacco whitefly, Bemisia tabaci. Complex III isolated from whitefly was optimally inhibited by hydroxy analogues with lower Log Ko/w values (6.0-6.5) and was also more sensitive than the blowfly enzyme to all the compounds tested.     

闹羊花素-III对菜青虫神经系统的影响

以闹羊花素 - III处理 5龄菜青虫幼虫 ,试虫乙酰胆碱酯酶 (ACh E)的活体活性和离体活性均与对照无明显差异 ,乙酰胆碱 (ACh)含量显著降低 ;对 Na - K - ATP酶、Ca2 -Mg2 - ATP酶比活力有可逆性激活作用 ,处理后 2 4 h比活力提高 ,尤以低剂量 1μg·虫 -1处理的比活力显著提高 ;处理后 6 0 h,以 1～ 3μg·虫 -1处理的比活力恢复正常 ,以 5～ 10μg·虫 -1处理的比活力显著低于对照。