兰州百合连作土壤水浸液自毒作用研究

【目的】探讨兰州百合(Lilium davidii var.unicolor salisb)连作土壤水浸液对自身幼苗生长的障碍因素及其作用机制。【方法】设置蒸馏水(CK)及正茬、连作2年、连作4年兰州百合根际土壤水浸液各50,100,200,300 mg/mL,共13个处理,以兰州百合种球为受试对象,测定不同条件下兰州百合幼苗生长、抗氧化酶活性、渗透调节物质及细胞膜透性的变化,并利用GC-MS技术分析各处理土壤中存在的主要自毒物质。【结果】正茬、连作2年及连作4年兰州百合根际土壤水浸液对兰州百合幼苗的生长均存在"低促高抑"现象,且抑制作用随连作年限的延长而增强。随水浸液质量浓度的增加,兰州百合幼苗CAT和SOD活性逐渐升高,POD活性先上升后下降,MDA含量、相对电导率、脯氨酸及可溶性糖含量的变化呈不断上升趋势,当水浸液质量浓度上升至300 mg/mL时,3个处理中各指标的上升或下降程度与对照相比均达显著差异水平(P0.05)。兰州百合正茬、连作2年及连作4年根际土壤中分别鉴定出9,15和17种化合物,主要包括2,3-丁二醇、1,2,3-三甲苯、邻苯二甲酸二丁酯、对苯二甲酸二辛酯、抗氧剂2246等化合物,其中大部分为自毒物质。【结论】兰州百合正茬、连作2年及连作4年根际土壤水浸液质量浓度达到300 mg/mL时,对其幼苗的生长会产生显著抑制作用。连作土壤中存在的自毒物质可以改变兰州百合植株体内的抗氧化酶活性,破坏细胞膜结构和功能,抑制兰州百合植株的生长,是导致兰州百合连作障碍发生的重要原因之一。     

朱顶红幼嫩花梗胚性愈伤组织诱导和高效植株再生

为建立高效的朱顶红植株再生和种苗繁育技术体系，以幼嫩花梗为外植体开展胚性愈伤组织诱导和植株再生研究。对2,4-D和噻苯隆（TDZ）浓度、外植体发育时期及大小进行了筛选，结果表明：将切片厚度为1 mm的幼嫩花梗外植体置于添加0.5 mg ? L-1 TDZ 和2.0 mg ? L-1 2,4-D的MS固体培养基上培养8周，胚性愈伤组织诱导率最高，达85.3%。将胚性愈伤组织转移至相同的培养基上，每月继代1次，平均每月增殖10.6倍。在不含任何生长调节剂的MS培养基上，胚性愈伤组织的植株再生率达98.0%，平均每块愈伤组织可再生出12.3个小植株。经过36次（3年）继代培养后，胚性愈伤组织的增殖和植株再生效率没有显著变化。幼苗移栽至温室驯化，成活率达97.5%。再生植株移栽到田间，没有发现明显的表型变异。对随机选择的再生植株和母株进行简单序列重复区间（ISSR）扩增分析，证实再生植株没有发生DNA水平变异。     

内生菌与雷公藤细胞悬浮共培养的生理生化特性

将2株雷公藤内生真菌Fusarium oxysporum NS33与Penicillium steckii NS6、2株内生细菌Enterobacter cloacae sub sp LG3与Serratia marcescens LY1及其组合分别与雷公藤细胞悬浮共培养,对不同培养体系内雷公藤细胞的生长及其生理生化特征进行研究。结果显示,在共培养前期,与对照相比,接种单一内生菌株提高了细胞的干重,其中菌株NS6的促生效果最明显;而在共培养后期,无论是单一内生菌还是混合内生菌均对细胞生长具有抑制作用。内生真菌和菌株组合处理的培养液p H值有明显的升高,而内生细菌LY1则明显降低了培养液的p H值,其具有产酸性。另外,当雷公藤细胞同混合菌株共培养时,培养基中总糖消耗量是最大的,而接种单独菌株时则对细胞可溶性蛋白含量具有一定的提高作用。接种内生菌会影响雷公藤细胞的POD、CAT及SOD活性,与对照相比,接种单独菌株会更加提升POD与CAT的活性,而细胞MDA含量则明显下降。     

Effect of dietary GroBiotic®‐A supplementation as a prebiotic on the intestinal microflora,growth performance,haemato‐serological parameters,survival rate and body composition in juvenile beluga (Huso huso Linnaeus, 1754)

The objectives of the present study were to investigate of GroBiotic^®‐A (GBA) on growth, autochthonous intestinal microbiota and haemato‐serological parameters of beluga juvenile. A total of 180 fish (40.82 ± 5.81 g) were fed diets containing graded levels of GBA (0, 5, 10 and 20 g kg^?1 diet) for 8 weeks. No significantly differences in body composition, total viable aerobic bacteria, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, neutrophils, eosinophils, monocytes, albumin, glucose, triglyceride, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase were detected between treatment groups. The fish fed on 10 and 20 g kg^?1 GBA significantly showed higher lactic acid bacteria, final weight, body weight increases, weight gain and lower feed conversion ratio compared with the control and 5 g kg^?1 groups. The group fed 20 g kg^?1 GBA showed a highly significant difference in condition factor, survival rate, final length, total red and white blood cells, lymphocytes, haematocrit, haemoglobin, total protein, total immunoglobulin and lysozyme activity. The specific growth rate of the treatment groups was significantly elevated compared with the control groups. These results indicated that GBA at level 20 g kg^?1 improved growth, welfare and survival of beluga juvenile.     

磷酸钠对粉红单端孢的离体抑菌作用研究

以引起果蔬采后病害的重要病原物粉红单端孢(Trichothecium roseum)为研究对象,探究离体条件下不同浓度磷酸钠对T. roseum菌丝生长和孢子萌发的抑制作用及其初步机理。结果表明,不同浓度磷酸钠处理均可抑制T. roseum菌丝生长和孢子萌发,且随着处理浓度的增加,抑制效果增强。此外,2.0 mg/mL磷酸钠处理降低了T. roseum胞外相对电导率,提高了胞外丙二醛和可溶性蛋白含量,降低了胞外可溶性糖含量。扫描电镜结果显示,2.0 mg/mL磷酸钠处理的孢子表面粗糙且发生皱缩。因此,离体条件下磷酸钠能够抑制T. roseum生长,其抑菌机理与细胞膜结构的破坏有关。     

马链球菌兽疫亚种烯醇化酶对小鼠肺泡巨噬细胞吞噬功能的影响

旨在研究马链球菌兽疫亚种（Streptococcus equi ssp.zooepidemicus，SEZ）烯醇化酶（enolase，Eno）对小鼠肺泡巨噬细胞（RAW264.7）吞噬能力的影响。通过构建原核表达质粒获得重组烯醇化酶（rEno），采用台盼蓝活细胞计数法，判定在不同处理浓度和时间下rEno蛋白对RAW264.7细胞的细胞毒性。将rEno蛋白与RAW264.7细胞共孵育后，用SEZ作用于细胞并检测细胞吞菌数量，判断RAW264.7细胞对SEZ的吞噬活性。进一步通过活细胞稳定同位素标记技术（SILAC）和蛋白质谱分析技术（LC-MS/MS），筛选到RAW264.7细胞中可能与SEZ Eno存在相互作用的候选蛋白。结果发现，10 μg·mL^-1 rEno蛋白处理对RAW264.7细胞有明显的细胞毒性，且10 μg·mL^-1 rEno蛋白处理RAW264.7细胞2和4 h可显著抑制其对SEZ的吞噬作用（P<0.01、P<0.05）。初步筛选到RAW264.7细胞中动力蛋白激活蛋白亚单位蛋白（dynactin subunit protein 2，Dctn）、整合素α-M蛋白（integrin alpha-M）等17种可能与Eno发生互作的蛋白。本研究获得了rEno重组表达蛋白，发现rEno可减少RAW264.7细胞对SEZ的吞噬，互作蛋白的初步筛选也为进一步揭示Eno在SEZ抗吞噬中的作用机制奠定了基础。     

Expression and function of circular RNA_0000231 in non-small-cell lung cancer

AIM: To investigate the expression and function of circular RNA_0000231 (circ_0000231) in non-small-cell lung cancer (NSCLC). METHODS: RT-qPCR was used to detect the expression of circ_0000231 in the NSCLC tissues and cell lines. circ_0000231 small interfering RNA (si-circ_0000231) or negative control siRNA of circ_0000231 (NC) was transfected into the NSCLC cells. The proliferation and apoptosis of the NSCLC cells were detected by CCK-8 assay, colony formation assay and flow cytometry, respectively. The expression of cyclin D1 (CCND1) and anti-apoptotic protein Bcl-2 were determined by RT-qPCR and Western blot. RESULTS: The expression of circ_0000231 in the NSCLC tissues and cell lines was significantly up-regulated compared with precancerous tissues and lung epithelial cells BEAS-2B (P<0.05). After transfection of NSCLC cells with si-circ_0000231, the cell viability, colony formation numbers were significantly decreased, and the apoptotic rate in si-circ_0000231 group was significantly increased as compared with NC group (P<0.01). In addition, the results of RT-qPCR and Western blot showed that transfection of si-circ_0000231 inhibited the expression of CCND1 and Bcl-2 (P<0.01). CONCLUSION: The expression of circ_0000231 is significantly increased in the NSCLC tissues and cells. Knock-down of circ_0000231 expression significantly inhibits the proliferation of NSCLC cells.     

猪lncRNA TCONS_00791383对骨骼肌卫星细胞增殖分化的影响

为了探究lncRNA TCONS_00791383对猪骨骼肌卫星细胞增殖和分化的影响。本研究利用qRT-PCR技术检测出生7 d内大白仔猪6种组织（心、脾、肺、肾、背肌和腿肌）以及猪骨骼肌卫星细胞增殖分化前后TCONS_00791383的表达水平；通过设计反义核苷酸（antisense oligonucleotides，ASO）片段在猪骨骼肌卫星细胞中对TCONS_00791383进行敲低，检测敲低TCONS_00791383之后增殖分化标志基因的表达量变化；通过trans （co-expression）对TCONS_00791383进行靶基因预测，使用DAVID对其进行GO富集和KEGG通路分析。结果显示，TCONS_00791383在猪心脏中表达量最高，在脾和肾组织中不表达。在骨骼肌卫星细胞从增殖到分化的过程中，TCONS_00791383的表达量逐渐上升，且在分化后30 h表达量达到最高。在使用ASO片段敲低TCONS_00791383之后，与对照组相比，在分化24 h，增殖标志基因Pax3、Pax7表达量显著或极显著降低（P<0.05，P<0.01），分化标志基因MyoG表达量极显著降低（P<0.01），在分化48 h，增殖标志基因Pax3表达量极显著降低（P<0.01），Pax7表达量显著降低（P<0.05），分化标志基因MyHC表达量显著降低（P<0.05）。预测得到的相关靶基因富集到AMPK、ATP等多个与骨骼肌卫星细胞增殖和分化过程相关的重要信号通路。本研究表明，lncRNA TCONS_00791383可能促进猪骨骼肌卫星细胞的增殖和分化。     

A New Bioassay Platform Design for the Discovery of Small Molecules with Anticancer Immunotherapeutic Activity

Immunotherapy takes advantage of the immune system to prevent, control, and eliminate neoplastic cells. The research in the field has already led to major breakthroughs to treat cancer. In this work, we describe a platform that integrates in vitro bioassays to test the immune response and direct antitumor effects for the preclinical discovery of anticancer candidates. The platform relies on the use of dendritic cells that are professional antigen-presenting cells (APC) able to activate T cells and trigger a primary adaptive immune response. The experimental procedure is based on two phenotypic assays for the selection of chemical leads by both a panel of nine tumor cell lines and growth factor-dependent immature mouse dendritic cells (D1). The positive hits are then validated by a secondary test on human monocyte-derived dendritic cells (MoDCs). The aim of this approach is the selection of potential immunotherapeutic small molecules from natural extracts or chemical libraries.