呋喃丹降解菌CDS-1的双标记菌株的构建

用Sau3AI消化呋喃丹降解菌Sphingomonassp.CDS-1的基因组DNA,将所得DNA片段与BamHⅠ酶切的启动子探针载体pRobe-GFP酶连后转化E.coliDH5α感受态细胞,在选择性平板上培养,从大约1×104个菌落中筛选到50个含启动子片段的阳性克隆。挑选其中一个发光强度最强的阳性克隆F7,将它的重组质粒pF7用EcoRⅠ和HindⅢ双酶切后得到包含Sphingomonassp.CDS-1启动子和gfp基因的DNA片段,将该片段克隆到广宿主载体pPZP201上,得到pPZP201-gfp质粒。将pPZP201-gfp通过三亲接合转移至Sphingomonassp.CDS-1中得到GFP标记菌株CDS-gfp,经荧光显微镜观察,gfp基因在CDS-gfp中表达量很高。对标记菌株进行连续传代10次(48h/次),发现pPZP201-gfp依然存在,而且发光明显。通过NotⅠ酶切位点把linA基因连接到pUT/mini-Tn5上构建新的转座子载体pUT/mini-Tn5-linA。以pRK600为辅助质粒将pUT/mini-Tn5-linA引入到CDS-1中,linA基因通过转座作用,插入到CDS-gfp的染色体中,得到双标记菌株CDS-GFP-LinA。该菌株是一株能同时降解γ-六六六和呋喃丹的基因工程菌,本研究的结果为研究Sphingomonassp.CDS-1的生态学行为奠定了基础。     

影响非洲菊愈伤组织诱导和增殖的因素

以非洲菊(Gerbera jamesonii Bolus)7个品种的叶片和带叶叶柄为外植体,接种到附加0.5、1.5和2.0 mg L-1 2,4-D的MS培养基上培养,各品种均能诱导出愈伤组织并增殖。愈伤组织的诱导和增殖状况均是叶片好于叶柄,但各品种之间存在显著差异。将品种F30和Ⅱ的叶片和带叶叶柄接种到含不同浓度单一细胞分裂素(6-BA、TDZ、KT)的MS培养基上培养,均未能诱导出愈伤组织,而在含2.0 mg L-1 6-BA 0.5 mg L-1 NAA的培养基上可以诱导出愈伤组织,且由品种Ⅱ叶柄诱导产生的愈伤组织可再分化出芽,品种F30诱导的愈伤组织却不能分化,但在其叶柄基部可直接出芽。以上结果说明,生长素是非洲菊愈伤组织诱导和增殖所必须的,非洲菊愈伤组织诱导、增殖和芽再生方式受品种及外植体类型的影响。     

Role of Diverse Non-Systemic Fungal Endophytes in Plant Performance and Response to Stress: Progress and Approaches

Plant–fungal symbiotic associations are ubiquitously distributed in natural plant communities. Besides the well-studied mycorrhizal symbiosis and grass systemic clavicipitaceous endophytes, recently, nonsystemic and horizontally transmitted fungal endophytes serving as plant symbionts have been increasingly recognized. Pure culture isolation and culture-independent molecular methods indicate that all parts of healthy plant tissues potentially harbor diverse and previously unknown fungal lineages. Limited evidence also supports a hypothesis that endophytic mycobiota dynamics may have a role in evolution of plants. High variability or “balanced antagonism” can be generally characterized with host–endophyte interactions, which implies that the outcome of symbiotic interactions can fall within a continuum ranging from mutualism to commensalism, and ultimately pathogenicity. Despite this complicated system, admittedly, fungal endophytes really endow the host with an extended phenotype. Accumulating facts illustrate that plant nutrition acquisition, metabolism, and stress tolerance may be strengthened or modulated via fungal symbionts. Piriformospora indica, a member of the order Sebacinales, simultaneously confers host resistance to biotic and abiotic stress. The ecological relevance of other fungal groups, including foliar endophytes, root dark septate endophytes (DSEs), some opportunistic and avirulent microsymbionts (for example, Trichoderma and Fusarium), and even uncultured fungi structurally and physiologically integrated with host tissues, are also being deeply exploited. Production of bioactive metabolites by fungi, overexpression of stress-related enzymes, and induced resistance in hosts upon fungal colonization are responsible for direct or indirect beneficial effects to hosts. More knowledge of endophyte-mediated enhancement of host performance and fitness will offer alternatively valuable strategies for plant cultivation and breeding. Meanwhile, with unprecedented loss of biodiversity, discovery of indigenously novel symbiotic endophytes from natural habitats is urgently needed. In addition, we present some approaches and suggestions for studying host–endophyte interactions.     

Coflex植入术与Quadrant通道下TLIF结合经皮Sextant椎弓根螺钉治疗退行性腰椎管狭窄症的疗效对比

目的:对比棘突间动态稳定装置Coflex系统植入与Quadrant通道结合经皮Sextant椎弓根螺钉内固定术治疗退行性腰椎管狭窄症的短期疗效.方法:抽取兰州军区兰州总医院骨科中心脊柱外科及第四军医大学唐都骨科医院脊柱外科的30例住院治疗退行性腰椎管狭窄症的患者,随机化分为2组,每组15例,分别行Coflex系统植入和Quadrant通道结合经皮Sextant椎弓根螺钉内固定术,观察比较两组的手术时间、出血量、术后住院时间、术前和术后6个月Oswestry功能障碍指数(Oswestry disability index,简称ODI)及视觉模拟评分法(Visual Analogue Scale/Score,简称VAS).结果:两组术前、术后6个月ODI及VAS评分对比差异有统计学意义,而在手术时间、术中出血量及术后住院天数方面Coflex组优于Quadrant+Sextant组,两组在术后6个月ODI评分方面差异无统计学意义,在术后6个月VAS评分方面Quadrant+Sextant组优于Coflex组,随访期间两组无并发症发生.结论:Coflex植入术及Quadrant通道结合经皮Sextant椎弓根螺钉内固定术均为治疗退行性腰椎管狭窄症的有效手段,但其各有特点,在临床工作中,应当严格掌握手术适应症,选择适当的手术方案,从而在最小的创伤和侵扰的同时获得最佳的疗效.     

野生碧玉兰组培快繁技术

以云南野生碧玉兰（Cymbidium lowianum）种子无菌萌发的试管苗为试验材料,进行其丛生芽诱导增殖、生根的组培快繁技术体系研究。结果表明：适宜的增殖培养基配方为1/2MS＋6-BA 2.0 mg/L＋KT 0.5 mg/L＋NAA 0.2 mg/L,增殖率可达300%;生根培养基的配方为1/2MS＋NAA 1.5 mg/L＋6-BA 0.3 mg/L,其根数多,健壮。     

奸狡长蠹属Apate六种识别

研究了奸狡长蠹属Apate 6个种:钻孔奸狡长蠹Apate terebrans(Pallas)、杂奸狡长蠢Apate degener Murray、射影奸狡长蠹Apate reflexa Lesne、咖啡黑长蠹Apate monachus Fabricius、毛额奸狡长蠹Apate femoralis F&hraeus和毛跗奸狡长蠹Apate indistincta Murray,其中咖啡黑长蠹是我国进境植物检疫性害虫.提供了上述6种奸狡长蠹的鉴定检索表,并分别描述了主要形态特征、寄主、分析和经济重要性.     

非洲菊试管苗叶柄愈伤组织的诱导与分化研究

以非洲菊(Gerbera janesonii Bolus)品种‘Sunanda'试管苗幼叶的带叶叶柄为材料,研究了培养基、外植体类型和继代次数等因素对愈伤组织诱导及分化的影响.结果表明:培养基上附加不同植物生长调节剂所诱导出的愈伤组织在形态和分化能力上存在显著差异,叶柄基部诱导愈伤组织的最适培养基是MS+TDZ 0.3 mg L-1+NAA0.1 mg L-1.外植体以叶片长度＞0.5 cm,叶片已舒展,颜色嫩绿的幼叶最佳,继代培养基以MS+KT 1.0 mg L-1较适宜,愈伤组织在分化培养基MS+6-BA 2.0 mg L-1+NAA 0.1 mg L-1上分化出芽的同时还会增殖,分化率达87.4%,继代培养2次的愈伤组织分化率可提高至95%.不定芽在生根培养基1/2MS+IBA0.6 mg L-1上的生根率达100%,试管苗移栽45 d后,成活率达97%以上.     

玉米SSR引物在芒属植物遗传多样性分析的应用研究

目的:本文为了探索芒属植物的遗传多样性,方法:运用SSR分子标记的方法,用30对玉米SSR引物对15份中国湖南省的野生芒属材料进行扩增.结果:结果表明:30对引物共扩增出159条带,其中多态性条带121个,占76.10%.平均Nei's基因多样度为0.1992,平均Shannon信息指数为0.3139.UPGMA聚类分析显示,15份材料在遗传相似系数(GS)为0.75水平上,聚成三大类.第一大类由芒组成,第二大类由五节芒组成,第三大类由南获组成.这与形态学上的分类吻合.结论:玉米的SSR引物对于芒属植物遗传多样性分析仍具有很好的可行性.     

Hypomethylated and hypermethylated profiles of H19DMR are associated with the aberrant imprinting of IGF2 and H19 in human hepatocellular carcinoma

In this study, 39 human hepatocellular carcinoma (HCC) tissues and 7 normal adult liver tissues were screened for heterozygous polymorphisms in IGF2, H19, and the differentially methylated region of H19 (H19DMR) using PCR-RFLP and PCR sequencing. The imprinting of IGF2 and H19 was examined by RT-PCR-RFLP, while the methylation profile of H19DMR was detected by bisulfite sequencing from every informative sample. Of the informative HCC samples 47.06% (8 of 17) demonstrated a gain of imprinting of IGF2, and 21.74% (5 of 23) of the informative HCC samples demonstrated a loss of imprinting of H19. Interestingly, we found three methylation profiles for H19DMR in the informative HCC samples: hyper-, medium-, and hypomethylated profiles. Furthermore, the hypomethylated and hypermethylated profiles were immediately associated with aberrant imprinting of IGF2 and H19.