茉莉酸甲酯诱导巨桉对桉树枝瘿姬小蜂的抗性

为探讨茉莉酸甲酯( MeJA)诱导巨桉幼苗防御反应的生化机制及其对桉树枝瘿姬小蜂的抗性效应,在室内采用喷施不同浓度MeJA处理,测定并分析了MeJA对桉叶苯丙氨酸解氨酶( PAL)、超氧化物歧化酶( SOD)、过氧化物酶( POD)和多酚氧化酶(PPO)4种防御酶活性,以及胰蛋白酶抑制剂(TI)和胰凝乳蛋白酶抑制剂(CI)2种植物蛋白酶抑制剂活性的影响。结果表明,喷施MeJA处理24-148 h后,巨桉幼苗叶片PAL、 SOD、 POD和PPO 四种防御酶和TI、 CI两种蛋白酶抑制剂活性均有不同程度的变化;用1.00 mmol·L-1 MeJA处理后桉树枝瘿姬小蜂种群趋势指数为24.13,防治效果达70.98%。 MeJA处理可诱导巨桉幼苗产生明显的防御反应,相关防御酶活性的变化与MeJA浓度和处理时间有关; MeJA可诱导巨桉幼苗产生抗虫性,对桉树枝瘿姬小蜂繁殖力和种群趋势指数产生影响,具有明显的防治效果。     

臭椿多倍体诱变的初步研究

用改良琼脂法,即0.2%秋水仙碱加1.0%琼脂溶胶对臭椿[Ailanthus altissima（Mill.）swingle.]进行24 h,48 h,72 h多倍体诱变,诱变率分别是61.90%,62.07%,46.88%.依据多倍体幼苗形态特征发现多倍体后代臭椿的生物学特征与对照相比有显著差异。     

接种生防菌和病原菌对香蕉抗枯萎病的诱导

使用2株生防枯草芽孢杆菌A5-6,C10-1和香蕉枯萎病病原菌（Foc4）,以不同的接种方式对4～5叶香蕉组培苗进行根部接种,以苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）这3种与植物抗病性密切相关的酶活性变化为指标,研究植物产生抗性的时间和强度的变化趋势。结果表明,经过生防菌A5-6和C10-1诱导处理的叶片PAL,POD,PPO的活性均高于对照（CK）,生防菌和病原菌混合接种处理的POD和PPO酶活峰值高于生防菌和病原菌单独接种的处理。     

Clinical outcome in 94 cases of dermal haemangiosarcoma in dogs treated with surgical excision: 1993-2007*

Canine dermal haemangiosarcoma (HSA) is believed to have a better prognosis compared to HSA in other organs, but outcome has only been reported in a small number of dogs. The purpose of this study was to assess outcome and prognostic factors in a larger cohort of dogs with dermal HSA. Clinical data was collected retrospectively for 94 dogs and histopathology was reviewed in 53 dogs. Median overall survival time was 987 days. Dogs of predisposed breed with ventral location and histologic solar changes had longer survivals. Loco-regional recurrence occurred in 72/94 (77%) dogs. Predisposed breeds with ventral location and multiple masses were more likely to develop recurrence. Non-predisposed breeds with invasive tumours were more likely to develop metastasis. Results suggest that dogs with solar-induced dermal HSA may have high recurrence rates, but prolonged survivals. Dogs with non-solar tumours may be at increased risk for metastasis and shorter survival.     

植物诱发突变技术育种研究现状与发展前景

自1928年以来,诱发突变技术应用于农作物新材料创制和优良新品种培育已经在解决世界粮食安全与营养供给中发挥显著作用。据不完全统计,截至2009年9月,世界上60多个国家在170多种植物上利用诱发突变技术育成和推广了3088个突变品种,其中中国在45种植物上育成了802个突变品种,占目前国际诱变育成品种数据库中总数的四分之一而位居世界第一。中国育成的突变品种年最大种植面积900万hm2,每年为国家增产粮、棉、油10~15亿kg,社会经济效益超过20亿元。近年来,加速器离子束辐照、空间环境诱变等新型诱变手段,以及传统核辐射诱变技术的有效利用等在我国农作物诱变改良与新基因挖掘中的应用日趋活跃。植物基因组学和高通量DNA技术（如TILLING等）的发展将把传统诱变育种推向分子突变育种新时代,并将在支撑我国及世界粮食安全领域发挥更大作用。     

茶尺蠖信息素结合蛋白PBP2的基因克隆、原核表达及其结合功能

【目的】茶尺蠖(Ectropis obliqua)是中国茶区主要的鳞翅目害虫,其幼虫暴食性常给茶园带来巨大损失。鳞翅目昆虫雌雄个体间普遍存在着性信息素通讯环节,而茶尺蠖性信息素识别途径一直鲜有报道。论文旨在通过对茶尺蠖性信息素识别过程中的结合蛋白基因进行鉴定和功能研究,为茶尺蠖性信息素化学通讯和嗅觉信息识别传递机制提供理论依据。【方法】利用RT-PCR技术对从雄虫触角转录组数据中首次鉴定和发现的一个茶尺蠖信息素结合蛋白基因(pheromone-binding protein,PBP)2(EoblPBP2)进行全长cDNA序列克隆(Gen Bank登录号为KX421383)后,将该基因与pET32a载体连接构建表达载体。随后向导入pET32a/EoblPBP2表达质粒的大肠杆菌BL21(DE3)中对其表达载体加入终浓度1 mmol·L~(-1)的IPTG进行蛋白的诱导表达,进一步利用镍NTA琼脂糖凝胶柱和含有咪唑的上清缓冲液分离目的蛋白,以PBS缓冲液作为透析液纯化得到高浓度重组蛋白。最后通过荧光竞争法,利用N-苯基-1-萘胺(N-phenyl-1-naphthylamine,1-NPN)作为荧光报告子以放大荧光信号,随后向重组蛋白与1-NPN混合体系中分别加入(Z,Z,Z)-3,6,9-十八碳三烯以及10种测试气味后经过分子荧光光度计扫描得到相对荧光值,计算各配基的解离常数KD,研究重组蛋白与茶尺蠖性信息素和茶树挥发物的生理功能。【结果】EoblPBP2全长为492 bp,编码了163个氨基酸,蛋白相对分子质量为15.9kD,等电点为4.983,具有保守的6个半胱氨酸,根据分子进化树分析其应归属于昆虫PBPs家族。结合功能结果显示,10种测试气味均能将1-NPN与茶尺蠖EoblPBP2重组蛋白的混合体系于420 nm处的相对荧光值降至50%以下。其中β-紫罗兰酮、邻苯二甲酸二丁酯、苯乙醛、癸醛和反-2-癸烯醛等5种茶树挥发物质与EoblPBP2重组蛋白的结合能力较强,解离常数KD分别为7.923、14.830、30.368、28.068和27.597μmol·L~(-1)。而性信息素成分之一的(Z,Z,Z)-3,6,9-十八碳三烯与EoblPBP2的解离常数KD仅为172.591μmol·L~(-1),仅小于苯甲醇的解离常数KD 230.880μmol·L~(-1),而远远大于上述5种气味物质。表明EoblPBP2重组蛋白具有茶尺蠖性信息素成分((Z,Z,Z)-3,6,9-十八碳三烯)和植物挥发物质广谱结合能力,而其与性信息素的亲和力弱于大部分测试植物挥发物。【结论】EoblPBP2能与包括性信息素成分在内的多种植物挥发物结合,可能是一种具备特殊复合功能的信息素结合蛋白,可用之进一步研究茶尺蠖的性信息素识别和传递途径。     

Direct and host‐mediated interactions between Fusarium pathogens and herbivorous arthropods in cereals

Fusarium head blight and fusarium ear rot diseases of cereal crops are significant global problems, causing yield and grain quality losses and accumulation of harmful mycotoxins. Safety limits have been set by the European Commission for several Fusarium‐produced mycotoxins; mitigating the risk of breaching these limits is of great importance to crop producers as part of an integrated approach to disease management. This review examines current knowledge regarding the role of arthropods in disease epidemiology. In the field, diseased host plants are likely to interact with arthropods that may substantially impact the disease by influencing spread or condition of the shared host. For example, disease progress by Fusarium graminearum can be doubled if wheat plants are aphid‐infested. Arthropods have been implicated in disease epidemiology in several cases and the evidence ranges from observed correlations between arthropod infestation and increased disease severity and mycotoxin accumulation, to experimental evidence for arthropod infestation causing heightened pathogen prevalence in hosts. Fusarium pathogens differ in spore production and impact on host volatile chemistry, which influences their suitability for arthropod dispersal. Herbivores may allow secondary fungal infection after wounding a plant or they may alter host susceptibility by inducing changes in plant defence pathways. Post‐harvest, during storage, arthropods may also interact with Fusarium pathogens, with instances of fungivory and altered behaviour by arthropods towards volatile chemicals from infected grain. Host‐mediated indirect pathogen–arthropod interactions are discussed alongside a comprehensive review of evidence for direct interactions where arthropods act as vectors for inoculum.     

水稻蛋白酶抑制剂基因OsLTPL164和OsLTPL151的组成型及诱导型表达模式

【目的】蛋白酶抑制剂（protease inhibitor, PI）是一类广泛存在于植物中的蛋白质,具有抵御植食性昆虫取食危害的功能。然而,水稻（Oryza sativa）PI基因在二化螟（Chilo suppressalis）取食过程中的表达模式尚不清楚。本研究旨在分析水稻蛋白酶抑制剂基因OsLTPL164和OsLTPL151在二化螟取食及机械损伤下的表达模式,为明确OsLTPL164和OsLTPL151在水稻防御二化螟中的作用及今后利用这两个基因构建转基因水稻株系打下基础。【方法】以东北地区常规种植的3个水稻品系辽盐2号（1654）、辽星17号（1665）和长白17号（1688）为研究对象,在二化螟危害关键时期（分蘖期）通过机械损伤和接虫处理,在处理后不同时间（0、3、6、12、24、48、72 h）分别对根、茎、叶3个组织进行取样,利用实时荧光定量PCR（RT-qPCR）检测3个水稻品系中OsLTPL164和OsLTPL151的表达模式。【结果】OsLTPL164在3个品系中的组织表达模式一致,在叶片和茎中的表达量均高于根部;OsLTPL151在3个品系中的组织表达模式不一致,在1654品系中茎和叶片中的表达量显著高于根部,但在1688和1665品系中根部的表达量显著高于茎和叶片;此外,这两个基因在3个品系间的相同组织中都有不同的表达模式,OsLTPL164在根、茎、叶中均呈现在1665品系中表达量最高、在1688品系中表达量次之、在1654品系中表达量最低的表达模式,但OsLTPL151在不同组织中的表达模式与OsLTPL164不同：在根中,OsLTPL151在1665品系中的表达量明显高于1688和1654品系;在茎中,OsLTPL151在1654和1665品系中的表达量明显高于1688品系;在叶中,OsLTPL151在1654品系中的表达量明显高于1665和1688品系。二化螟取食诱导OsLTPL164和OsLTPL151在3个品系的叶片中表达上调幅度高于茎和根,且在1665品系中上调的幅度较1688和1654品系中大。在二化螟取食和机械损伤处理不同时间后,两个基因均呈现表达水平先上升后下降再上升的趋势;OsLTPL164和OsLTPL151在机械损伤6 h后才被显著诱导表达,而二化螟取食3 h后便可诱导OsLTPL164和OsLTPL151上调表达。【结论】OsLTPL164和OsLTPL151在3个水稻品系中二化螟取食以及机械损伤均能诱导其表达,推测这两个基因可能与水稻抗二化螟有关,但这两个基因在不同水稻品系中其他具体的功能可能有所不同。     

RNAi as an emerging approach to control Fusarium head blight disease and mycotoxin contamination in cereals

Fusarium graminearum is a major fungal pathogen of cereals worldwide, causing seedling, stem base and floral diseases, including Fusarium head blight (FHB). In addition to yield and quality losses, FHB contaminates cereal grain with mycotoxins, including deoxynivalenol, which are harmful to human, animal and ecosystem health. Currently, FHB control is only partially effective due to several intractable problems. RNA interference (RNAi) is a natural mechanism that regulates gene expression. RNAi has been exploited in the development of new genomic tools that allow the targeted silencing of genes of interest in many eukaryotes. Host‐induced gene silencing (HIGS) is a transgenic technology used to silence fungal genes in planta during attempted infection and thereby reduces disease levels. HIGS relies on the host plant's ability to produce mobile small interfering RNA molecules, generated from long double‐stranded RNA, which are complementary to targeted fungal genes. These molecules are transferred from the plant to invading fungi via an uncharacterised mechanism, to cause gene silencing. Here, we describe recent advances in RNAi‐mediated control of plant pathogenic fungi, highlighting the key advantages and disadvantages. We then discuss the developments and implications of combining HIGS with other methods of disease control. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

多元混菌培养对棉花黄萎菌拮抗效果的研究

特基拉芽胞杆菌C-9和鞘氨醇杆菌A1是分离得到的2株对棉花黄萎菌具有较好生防效果的菌株,平板对峙试验测定菌株C-9与A1的抑菌率分别为77.8%和83.3%,根据脂肽类抗生素相关合成基因序列进行PCR扩增,2株生防菌都能检测到surfactin、fengycin和mycosubtilins相关基因片段。通过单因素试验对液体混菌培养体系进行初步筛选,得到对棉花黄萎菌具有较好防效的最佳混菌比例A1：C-9=1：9,在此比例下的混菌培养物对棉花黄萎菌的抑制能力较单菌株A1和C-9提高了131%和36.7%。镜检发现混菌培养物抑制可致黄萎菌菌丝发生膨大畸形。盆栽试验表明,混菌培养物对棉花黄萎病的防治效果可达66.7%,混菌培养物处理的棉花在挑战接种棉花黄萎菌后,棉花体内防御酶系CAT酶活快速响应,在达到峰值时比同时期的CK组增加了135.3%。POD和SOD的基础酶活较CK分别提高22.5%和39.8%,且MDA含量始终低于CK。综合分析表明,混菌发酵可提高菌株对黄萎菌的抑制效果,可通过直接抑制黄萎菌生长和诱导植物产生防御反应来提高对棉花黄萎菌的抗性。