芜菁花叶病毒不同分离物3'-cDNA片段的克隆及序列分析

 从河北、北京、山东泰安和潍坊等地区的萝卜、大白菜、甘蓝、油菜上得到8个芜菁花叶病毒(Turnip mosaic virus,TuMV)分离物,测定了它们3'-末端cDNA片段的序列。根据衣壳蛋白基因(cp)核苷酸序列可以将这8个分离物与另外2个TuMV分离物分为3组:泰安旧镇大白菜(JZBC)、甘蓝(JZGL)和萝卜(JZLB)分离物为一组;北京(BJILB)、潍坊萝卜分离物(WFLB)与引起萝卜红心病的TuMV分离物(WFLB99)为一组;泰安范镇、河北、潍坊(WFLB04)萝卜和泰安旧镇油菜(JZYC)上的TuMV分离物为一组。农壳蛋白氨基酸序列比较结果与此基本一致,所不同的是分离物WFLB99与所有分离物的差异均较大,形成单独一个分支。有必要对TuMV的变异情况和致病机理进行深入研究。     

2018年我国小麦赤霉病菌对多菌灵抗性检测

以多菌灵为主的苯并咪唑类杀菌剂一直是小麦抽穗扬花期防控赤霉病的主要手段之一。本研究对2018年我国主要麦区采集的1 464株赤霉病菌菌株进行多菌灵抗性分子检测。共检测出多菌灵抗性菌株97株,抗性频率为6.63%,同时发现抗性菌株以F167Y突变频率最高,其次为E198Q和F200Y。通过比较不同省份间多菌灵抗性发生频率发现,长江中下游麦区赤霉病菌群体抗性频率明显高于黄淮麦区群体。本研究相比之前研究中的抗性频率大幅度上升,表明在多菌灵的选择压力下,多菌灵抗性种群发展迅速。为防止抗性群体的进一步发展,致使多菌灵防治赤霉病失效,应采用混配、复配药剂、不同作用机理的杀菌剂交替轮换使用来防治小麦赤霉病。     

Suberoylanilide hydroxamic acid induces apoptosis of HepG2 cells by endoplasmic reticulum stress apoptotic pathway

AIM: To investigate the effect of suberoylanilide hydroxamic acid (SAHA) on the proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells and to explore its possible mechanism. METHODS: HepG2 cells were treated with SAHA at different concentrations for 48 h. The proliferation of HepG2 cells was detected by real-time cellular analysis. The protein levels of acetylated histones H3K9 and H3K27, glucose-regulated protein 78 (GRP78), protein kinase R-like endoplasmic reticulum kinase (PERK) and p-PERK were determined by Western blot. The cell apoptosis was analyzed by flow cytometry. RESULTS: Compared with control group, treatment with SAHA at 0.1 μmol/L and 1 μmol/L for 48 h showed no significant inhibitory effect on the proliferation of HepG2 cells, while SAHA at 6 μmol/L and 12 μmol/L significantly inhibited the proliferation of HepG2 cells (P<0.05). The results of Western blot showed that the protein levels of acH3K9, acH3K27, GRP78 and p-PERK increased significantly after treated with SAHA at diffe-rent concentrations for 48 h, while the protein level of PERK was decreased significantly (P<0.05). The results of flow cytometry analysis showed that the apoptotic rates of the HepG2 cells increased with the increase in SAHA concentration. CONCLUSION: SAHA up-regulates the acetylation of H3K9 and H3K27 in the HepG2 cells and induces apoptosis of HepG2 cells by activating the endoplasmic reticulum stress-related apoptosis pathway.     

SIRT1 promotes autophagy of pancreatic cancer cells induced by hypoxia via regulating FOXO1/RAB7 signaling pathway

AIM: To investigate the effect of SIRT1 on the autophagy of pancreatic cancer cells under hypoxia condition, and to analyze the underlying mechanism of regulating FOXO1/RAB7 signaling pathway. METHODS: Western blot and immunofluorescence methods were used to determine the expression of SIRT1 in the pancreatic cancer cells. The small interfering RNA targeting SIRT1 and SIRT1 over-expression plasmid were transfected into the pancreatic cancer Panc-1 cells. Confocal microscopy was used to detect the LC3 expression. Western blot was used to analyze the protein levels of LC3, p62 and FOXO1/RAB7 signaling pathway-related molecules. Co-immunoprecipitation was used to detected the protein interaction between SIRT1 and FOXO1. RESULTS: The expression level of SIRT1 in the nucleus of Panc-1 cells was increased under hypoxia condition. Compared with negative control under hypoxia condition, knock-down of SIRT1 expression attenuated the autophagy flux in the pancreatic cancer Panc-1 cells (P<0.05). Over-expression of SIRT1 increased the protein levels of FOXO1 and RAB7. On the contrary, knock-down of SIRT1 expression inhibited the protein levels of FOXO1 and RAB7. The protein interaction between SIRT1 and FOXO1 in the pancreatic cancer cells was observed. CONCLUSION: SIRT1 in pancreatic cancer Panc-1 cells under hypoxia condition is over-expressed in the nucleus. Down-regulation of SIRT1 inhibits autophagy and its mechanism may be related to FOXO1/RAB7 signaling pathway.     

马铃薯内生细菌的分离及环腐病拮抗菌的筛选鉴定

 本研究从大同、太原和内蒙古等地采集马铃薯块茎,分离到240株内生细菌,通过离体抑菌作用测定,共得到55株对环腐病菌有拮抗作用的菌株,占菌株总数的22.9%,抑菌圈半径最大的可达13 mm。按抑菌圈半径大小将拮抗菌分为强、中、弱三类。从中筛选出9个对环腐病等病菌具有较强拮抗作用的内生菌株进行了细菌学鉴定,结果表明:118为荧光假单胞生物型V (Pseudomonas fluorescens biovar V);110为短小芽孢杆菌(Bacillus pumilus);085为嗜热脂肪芽孢杆菌(Bacillus stearothermophilus);069为草生欧文氏菌(Erwinia herbicola);043为草莓黄单胞菌(Xanthomonas fragariae);A-10'、T3为芽孢杆菌属(Bacillus);H1-6为荧光假单胞菌(Pseudomonas fluorescens);116为短小杆菌属(Curtobacterium)。     

北京地区无土栽培越冬茬番茄品种筛选

为了筛选出适宜北京地区无土栽培的越冬茬番茄品种,对从国外引进的"丰收560""迪安娜""玛丽娅""粉妮娜"4个番茄品种进行了品种比较试验,以综合比较各品种的生长指标、果实性状和果实营养品质。结果表明:"迪安娜"综合表现较好,更适于北京地区无土栽培越冬茬生产。     

芽孢杆菌绿色荧光蛋白标记及其在小麦体表定殖的初探

 将来自质粒pAD4412的启动子和绿色荧光蛋白基因gfpmut3a插入大肠杆菌-枯草芽孢杆菌穿梭载体pBE2,构建成芽孢杆菌表达载体pGF P4412,用其转化野生型生防芽孢杆菌83-6和A-47等8个菌株,均得到良好的发光表型。质粒稳定性实验表明重组质粒pG FP4412稳定性为92%。借助荧光显微镜对gfp标记的菌株A-47-gfp在小麦体表的定殖进行初步的研究。结果表明:A-47-gfp能够在小麦根际及小麦体表定殖(包括根表和茎叶表面);相对于在茎叶表面定殖的A-47-gf p在根表定殖的菌体与根的结合更为牢固;从根基到根尖A-47-gfp的定殖量有明显的减少趋势。     

畜牧推广学教学体系改革探讨

畜牧推广学是是西北农林科技大学动物科学专业新开设的重要专业选修课之一。针对目前该门课程教学中存在的教材针对性不强、课时少、内容繁杂、学生对畜牧生产过程了解甚少而学习兴趣不高等问题。为了在有限的教学时间内帮助和引导学生更好地掌握畜牧推广学的相关知识和技能,提高教学效果,在总结笔者多年从事该门课程教学经验的基础上,文章从创新教材体系、优化教学内容、改进教学手段、改革教学方法、改革考试形式和考核方式等五个方面,对畜牧推广学教学体系改革的方向和措施进行了简要论述。     

热应激绍兴鸭不同组织HSP70基因mRNA表达研究

研究蛋鸭热应激条件下不同组织中热休克蛋白70(HSP70)基因mRNA表达规律,为揭示蛋鸭热应激反应机理提供参考。60只绍兴蛋鸭25℃饲养20d,其中30只进行40℃热应激处理1h,采取荧光定量PCR方法分别测定不同组织中HSP70mRNA的表达水平。试验组与对照组相比,肝脏、脾脏和胰腺组织HSP70mRNA表达差异不显著,其他6种组织HSP70基因表达量均有不同程度的增加,试验组心脏、腿肌、垂体、下丘脑、胸肌、肾脏中HSP70基因表达量分别高于对照组3.6倍、2.8倍、2.7倍、2.4倍、2.2倍和1.57倍。     

鸡软骨细胞体外分离培养鉴定以及过表达miR-15a对软骨细胞的影响

为分析miR-15a在肉鸡不同组织中的表达情况,并探究过表达miR-15a对体外培养鸡软骨细胞的影响。本研究首先通过倒置显微镜观察、PCR、凝胶电泳和甲苯胺蓝染色对体外分离培养的软骨细胞进行鉴定。通过实时荧光定量PCR检测miR-15a在肢体内外翻畸形(valgus-varus deformity, VVD)组和健康组肉鸡中(各3只)各组织的表达量。之后通过CCK8和EDU方法分析软骨细胞过表达miR-15a后细胞增殖情况。软骨细胞转染miR-15a mimics后,通过qPCR检测软骨细胞的标志基因Collagen-2、Aggrecan、Collagen-10,成熟分化基因Runx2、Sox9、VEGF、MMP9,炎性因子IL-1β、IL-6、IL-8、IL-10、TNF-α、TGF-β3以及凋亡基因Fas、FasL、Bcl-2的表达量。并构建FKBP5 3'UTR的野生型载体和突变型载体,通过双荧光素酶检测报告检测miR-15a与FKBP5的靶向关系。结果表明,本研究所用的胰蛋白酶、Ⅱ型胶原酶和透明质酸酶联合消化法成功分离得到状态良好的软骨细胞。荧光定量结果显示,miR-15a在各组织中均有表达,与健康组相比,miR-15a在VVD组的肝(P < 0.01)、脾(P < 0.05)、胸腺(P < 0.01)中的表达量显著升高,在心和胸肌组织中的表达量显著降低(P < 0.01)。CCK8与EDU分析结果显示,与NC组相比,过表达miR-15a组软骨细胞增殖速度显著降低(P < 0.01),增殖细胞数量显著减少(P < 0.01)。qPCR结果显示,与mimics NC组相比,miR-15a mimics组的软骨细胞标志基因Aggrecan、成熟分化基因Sox9、Runx2表达量显著降低(P < 0.05),Fas基因表达量极显著上升(P < 0.01),FasL基因和抗凋亡基因Bcl-2极显著下降(P < 0.01)。成功构建了FKBP5 3'UTR野生型和突变型载体,双荧光素酶检测报告结果显示预测的靶基因FKBP5与miR-15a没有靶向关系。本研究成功分离并鉴定了鸡软骨细胞,过表达miR-15a抑制鸡软骨细胞增殖、成熟和分化并促进细胞凋亡。