ATAF2正调控拟南芥对橡胶树白粉菌的抗病性

橡胶树白粉菌(Oidium heveae)侵染拟南芥野生型Col-0,激发拟南芥的抗病反应。该抗病反应依赖于EDS1（enhanced disease susceptibility 1）,EDS1在TIR-NB-LRR（Toll-Interleukin1 Receptor-nucleotide binding-leucine-rich repeat）类抗性基因介导的抗病信号通路中发挥非常重要的作用,但目前还不清楚具体的EDS1上、下游作用元件是什么。为了进一步研究橡胶树白粉菌在拟南芥上激发的抗疾信号通路,本实验室对接种橡胶白粉菌oidium heveae HN1106的拟南芥野生型Col-0进行了RNA-Seq数据分析,结果表明,拟南芥Col-0在接种橡胶树白粉菌4 d后,NAC家族 (ATAF1,2 and CUC2, NAM)转录因子ATAF2基因上调表达20倍,并且正调控拟南芥对橡胶树白粉菌的抗病性。另外,笔者通过体外蛋白质pull-down试验和体内原生质体免疫共沉淀试验,发现ATAF2可以直接与EDS1发生相互作用,这为将来进一步阐明EDS1抗病信号通路奠定了很好的基础。     

SGT1正调控橡胶树白粉菌在拟南芥上激活的抗病性

通过在拟南芥野生型Col-0和突变体sgt1b、eds1上接种橡胶树白粉菌Oidium heveae HN1106,分析了白粉菌细胞进入率、叶片发病症状、菌丝生长状态、细胞死亡和活性氧产生等表型。结果表明,与野生型Col-0相比,橡胶树白粉菌在拟南芥sgt1b上激发的早期抗病性、后期抗病性以及抗病反应部分降低,暗示着SGT1在稳定识别橡胶树白粉菌的抗性蛋白方面发挥着非常重要的作用。     

橡胶树白粉菌MAPK级联信号途径全基因组鉴定及途径模型建立

从全基因组水平鉴定橡胶树白粉菌(Oidium heveae)的MAPK级联信号途径基因,并对其进行Blast比对、蛋白质结构域及聚类分析,构建橡胶树白粉菌中的MAPK级联途径简图,为深入研究其MAPK级联途径的功能奠定基础。利用橡胶树白粉菌基因组数据库和小麦白粉菌(Blumeria graminis)的同源序列进行比对,获得25个MAPK信号途径相关基因。在橡胶树白粉菌基因组中发现了2个MAPK基因、2个MAPKK基因和5个MAPKKK基因。多重序列比对与保守位点分析表明,橡胶树白粉菌MAPK信号途径的激酶结构域均高度保守。在橡胶树白粉菌中构建Fus3/Kss1MAPK、Hog1 MAPK、Slt2(Mpk1)MAPK 3条MAPK级联途径,为深入探究植物病原真菌MAPK超家族的功能奠定了基础。     

橡胶白粉菌(Oidium heveae Steinmann)基因组DNA的提取方法

比较了2种菌源、3种方法提取橡胶树白粉病病原真菌橡胶白粉菌(Oidium heveae BA.Steinmann)基因组DNA的效果。结果表明:无论采用单斑分离法收集还是直接收集橡胶白粉菌菌体,无论采用石英砂振荡破壁法、氯化苄法还是尿素法提取,均能获得满足常规分子生物学操作要求的基因组DNA;在基因组DNA的提取产率、完整性方面,各种方式之间略有差异,但无显著差别;2种来源菌体的基因组DNA的ITS序列分析结果一致,说明在无法进行单斑分离的情况下,可以利用直接收集的菌体提取基因组DNA。     

胶树白粉菌收集及DNA和RNA提取方法比较

橡胶树白粉菌（Oidium heveae）是专性寄生的病原真菌,难以获取足量和纯度高的菌体,因而不易提取到足够多和质量高的核酸,阻碍了该菌的分子生物学研究袁目前关于橡胶树白粉菌核酸提取方法少有报道.采用软毛笔刷取和醋酸纤维乙酯撕取两种方法收集白粉病菌遥在尝试使用常规的菌物RNA提取方法基础上袁通过优化操作步骤、方法等,研究出改良的Trizol法,用该法能高效率提取到纯度高的橡胶树白粉菌RNA。比较不同DNA提取方法的效率,推荐使用得率高、纯度好的OMEGAFungalDNA kit提取法,用于提取橡胶树白粉菌的DNA。     

3个基因共同参与拟南芥对橡胶树白粉菌的抗病性

通过在拟南芥野生型Col-0和突变体sag101,eds1及pad4上接种橡胶树白粉菌Oidium heveae HN1106,分析了拟南芥早期抗病性和后期抗病性表型。结果表明:与野生型Col-0相比,橡胶树白粉菌在拟南芥突变体sag101,eds1和pad4上激发的早期抗病性、后期抗病性以及抗病反应都显著降低,突变体eds1感病性最强,pad4次之,sag101最弱,暗示着PAD4与SAG101在橡胶树白粉菌抗性方面存在功能互补,三者共同参与了拟南芥对橡胶树白粉菌的抗病性。     

人IL-1Rα基因的克隆及原核表达的研究

IL-1Ra是第一个被发现的天然存在的细胞因子拮抗剂,结合于IL-1受体后不引起IL-1效应.文章通过RT-PCR从人的胎盘组织中克隆了人IL-1Ra基因,使其在大肠杆菌DH5α中重组表达.结果表明,克隆到了460bp左右的目的基因,并在大肠杆菌中成功表达了18 ku左右的目的蛋白,目的蛋白在大肠杆菌中表达量占总蛋白2...     

肉兔部分血浆蛋白多态性与生产性能关系的研究

以 8个品种 (杂交组合 )的肉兔为试材 ,利用 PAGE对血浆运铁蛋白 (Tf)、铜蓝蛋白 (Cp)、酯酶 -1 (Es-1 )和淀粉酶(Amy) 4个位点的蛋白多态性进行测定 ,并与其生产性能进行比较。结果表明 :Cp、Es-1、Amy 3个位点具有蛋白多态性。蛋白多态性与生产性能有密切的关系 ,Cp的 3种基因型对 1 0 0日龄体重、日增重均呈 AA相似文献   

橡胶树白粉病菌在疏水介质表面的侵染特征和RNA提取

将白粉菌孢子接种到石蜡膜(parafilm)介质表面,观察不同温度条件下橡胶树白粉菌(Oidium heveae B.A.Steinmann)菌株孢子在疏水介质上的侵染过程,确定0~24 hpi孢子侵染结构发育特征,提取侵染发育过程白粉菌的总RNA,采用RT-PCK扩增分析18S保守基因并评价其质量。结果表明:橡胶树白粉菌孢子在15~34℃温度条件下接种于parafilm介质表面能萌发并形成附着胞,萌发和附着胞形成的适温范围22~28℃,最适离体诱导温度22℃。孢子在parafilm介质表面0~24 hpi(hour Post moculation)侵染发育过程可分为未萌发(0hpi)、萌发(4 hpi)、附着胞形成(6,8 hpi)和次生附着胞形成(16,24 hpi)等4个阶段;采用改良Trizol方法提取白粉菌孢子侵染发育过程4个阶段总RNA,可满足转录组文库要求,并扩增18S序列,进化分析显示其与白粉菌科物种为同一分支。结果表明,病原菌孢子在22~28℃温度条件下能够在介质表面形成侵染结构,0,4,6,8,16,24 hpi侵染发育阶段总RNA可用于转录组测序分析研究。     

转Bt基因作物毒素在土壤中降解特性的研究进展

总结了国内外转Bt基因作物在土壤中降解特性的研究结果,讨论了土壤有机、无机组分与毒素蛋白的关系,阐明了转基因毒素蛋白在土壤中的降解与影响因素,揭示了转Bt基因作物在土壤中降解的生态环境效应,并提出了今后应深入研究的问题和方向.     

橡胶树白粉菌诱导寄主及非寄主植物产生活性氧积累的研究

采用DAB染色法观察了橡胶树、马占相思、芒果树和假败酱等植物叶片在接种橡胶树白粉菌后不同时间点的活性氧的积累和白粉病菌的侵入情况.结果表明,橡胶树叶片在接菌后24 h才能检测到微弱活性氧的积累,接菌后48 h活性氧的积累量略有增强,接菌后72 h达到最大强度,之后减弱,接菌后120 h白粉病菌产生分生孢子并且成功侵入叶片组织.马占相思叶片接菌后白粉菌与植物叶片互作的整个过程中活性氧变化规律与橡胶树观察结果相同,接菌后24 h出现活性氧积累,此后随时间的变化活性氧积累先增强后减弱,120 h白粉菌可以产生分生孢子并顺利侵入叶片组织.芒果树叶片接菌后12h即可检测到大量的活性氧产生,整个互作过程中,活性氧积累量大,接菌后120 h时白粉菌虽然可以产生分生孢子,但未能导致芒果叶片发病.假败酱叶片接种白粉菌后,接菌后12h可观察到强烈的活性氧积累,随时间的变化染色程度不断加深,染色斑范围扩大,接菌后72 h观察到白粉菌无法继续扩展,最终无法成功侵入叶片组织.观察结果揭示了活性氧,尤其是浸染早期活性氧的积累在植物抵抗白粉病侵染中发挥的重要作用.     

Independently evolved virulence effectors converge onto hubs in a plant immune system network

Plants generate effective responses to infection by recognizing both conserved and variable pathogen-encoded molecules. Pathogens deploy virulence effector proteins into host cells, where they interact physically with host proteins to modulate defense. We generated an interaction network of plant-pathogen effectors from two pathogens spanning the eukaryote-eubacteria divergence, three classes of Arabidopsis immune system proteins, and ~8000 other Arabidopsis proteins. We noted convergence of effectors onto highly interconnected host proteins and indirect, rather than direct, connections between effectors and plant immune receptors. We demonstrated plant immune system functions for 15 of 17 tested host proteins that interact with effectors from both pathogens. Thus, pathogens from different kingdoms deploy independently evolved virulence proteins that interact with a limited set of highly connected cellular hubs to facilitate their diverse life-cycle strategies.     

拟南芥At3g28220基因抗寒功能初步分析

采用RT-PCR分析、基因克隆、转化等方法对At3g28220基因功能进行了研究.结果发现At3g28220基因在拟南芥受到低温及盐胁迫时才会在拟南芥中表达,且在不同生长期不同器官中的表达量无明显差异.通过构建35s:At3g28220基因正反向表达载体转化拟南芥,T1植株经卡那霉素抗性筛选,RT-PCR检测,结果表明At3g28220基因已经整合到拟南芥基因组中,并在转录水平表达.正常生长条件下,转基因拟南芥与野生型拟南芥的生长未见明显区别,而经过低温胁迫研究发现,正向表达转基因拟南芥的冷冻耐受能力明显高于野生型植株.说明拟南芥hos10-1冷驯化能力的丧失是与At3g28220基因的表达下调有直接的关系.     

A bacterial virulence protein suppresses host innate immunity to cause plant disease

Plants have evolved a powerful immune system to defend against infection by most microbial organisms. However, successful pathogens, such as Pseudomonas syringae, have developed countermeasures and inject virulence proteins into the host plant cell to suppress immunity and cause devastating diseases. Despite intensive research efforts, the molecular targets of bacterial virulence proteins that are important for plant disease development have remained obscure. Here, we show that a conserved P. syringae virulence protein, HopM1, targets an immunity-associated protein, AtMIN7, in Arabidopsis thaliana. HopM1 mediates the destruction of AtMIN7 via the host proteasome. Our results illustrate a strategy by which a bacterial pathogen exploits the host proteasome to subvert host immunity and causes infection in plants.     

山西省小麦白粉病菌毒性结构初步分析

利用４３个山西省的小麦白粉菌株对３６个已知抗白粉病基因品种（系）和推广品种（系）进行毒力频率测定，结果表明对Ｐｍｌ，Ｐｍ３ａ，Ｐｍ５，Ｐｍ７，Ｐｍ８的毒力频率较高，不宜单独应用，对Ｐｍ４ａ，Ｐｍ４ｂ，Ｐｍ２ｘ，Ｐｍ２＋６及肯贵阿１号的毒力频率较低，是高抗基因，Ｐｍ２，Ｐｍ６介于以上两种类型之间，有一定的利用价值。对许多推广品种（系）毒力频率较高，说明目前存在着大面积感病寄主，生产上应做好防治准备。此外，菌源中存有极复杂的生理转化现象，其中对鉴别寄主低毒性的小种占优势。     

The Physiological and Molecular Responses of Arabidopsis thaliana to the Stress of Oxalic Acid

Many fungal phytopathogens can secrete oxalic acid （OA）, which is the crucial pathogenic determinant and plays important roles in pathogenicity and virulence of pathogen during infection process. However, how plants respond to OA stress still needs further characterization. In this study, we observed the physiological and molecular responses of Arabidopsis thaliana to OA stress. The leaves of 6-wk-old A. thaliana were sprayed with OA and distilled water respectively, and 0, 2, 4, 8, 12, and 24 h later, the leaves were collected and the contents of MDA, H2O2, and GSH, and the activities of CAT, SOD, and POD were determined and the expressions of PR1 and PDF1.2 were also studied. Under the stress of 30 mmol L-1 OA, SOD activity was first enhanced to reduce the accumulation of O2.-. But immediately, POD, CAT, and GSH all decreased extremely resulting in the accumulation of H2O2, and the MDA content increased 24 h later. GSH activity was enhanced significantly at 24 h after OA used. However, H2O2 wasn＇t eliminated at the same time, suggesting that the activity inhibitions of POD and CAT might be the reasons that caused Arabidopsis cells＇ impairment under OA stress. RT-PCR results indicated that PDF1.2, a marker gene of the JA/ET signaling was significantly induced; PR1, an indicator gene in SA signaling, was slighlty induced from 8 to 12 h after OA stress. In conclusion, Arabidopsis may recruit metabolism of reactive oxygen, both JA/ET and SA signaling pathways to respond to OA stress. These results will facilitate our further understanding the mechanisms of plant response to OA and OA-dependent fungal infection.     

石斑鱼生长激素基因的合成及其在拟南芥中的表达

为了使石斑鱼生长激素基因适合在植物中表达,重新合成了石斑鱼生长激素基因,对其密码子进行了优化,把合成的基因构建于植物表达载体pBI121上并转化模式植物拟南芥,获得了30个转基因抗性植株。对24株PCR阳性苗进行Northernblotting分析,结果表明,鱼类生长激素基因可以在转基因植物中表达,其表达在不同的转基因植株中存在明显差异,表达最强的植株与最弱的植株相比,二者表达量差异达到43倍。