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排序方式: 共有211条查询结果,搜索用时 218 毫秒
1.
The role of multiple ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporter genes from the plant pathogenic fungus Botrytis cinerea in protection against natural fungitoxic compounds was studied by expression analysis and phenotyping of gene-replacement mutants. The expression of 11 ABC (BcatrA–BcatrK) and three MFS genes (Bcmfs1, Bcmfs2 and Bcmfs4) was studied. All genes showed a low basal level of expression, but were differentially induced by treatment with cycloheximide and the plant defence compounds camptothecin, eugenol, psoralen, resveratrol and rishitin. The latter compounds induced expression of BcatrB at a high level. Eugenol was more toxic to BcatrB gene-replacement mutants than to the control isolates. Eugenol also caused an instantaneous increase in mycelial accumulation of the fungicide fludioxonil, a known substrate of BcatrB. However, there was no difference in virulence between the wild-type and BcatrB gene-replacement mutants on Ocimum basilicum, a plant known to contain eugenol. The results indicate that BcatrB is a transporter of lipophilic compounds, such as eugenol, but its role in virulence remains uncertain.  相似文献   
2.
伊氏锥虫多种克隆群体的采集及血清学检测   总被引:1,自引:1,他引:1  
针对伊氏锥虫抗原变异,国内外学者对抗原变异规律进行了研究,对其抗原变异程序、变异数量、变异频率等有了一定的了解,在此基础上进行免疫学研究进而寻求防治锥虫病的免疫学手段。但多局限于某种动物个体感染锥虫后的一小段有限的时间进行,所获得的抗原变异型数量较少,因而很难澄清如:一个虫株究竟能有多少变异机会,是以怎样的程序变异的等问题。  相似文献   
3.
We hypothesized that maternal nutrition during the first 50 d of gestation would influence the abundance of hexose transporters, SLC2A1, SLC2A3, and SLC2A5, and cationic amino acid transporters, SLC7A1 and SLC7A2, in heifer uteroplacental tissues. Angus-cross heifers (n = 43) were estrus synchronized, bred via artificial insemination, and assigned at breeding to 1 of 2 dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d of BW gain or RES = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d) in a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross-sections were collected from the horn ipsilateral to the corpus luteum, fixed in 10% neutral buffered formalin, sectioned at 5 µm, and stained via immunofluorescence for transporters. For each image, areas of fetal membrane (FM; chorioallantois), luminal epithelium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted for days 34 and 50. No transporters in target areas were influenced by a day × treatment interaction (P ≥ 0.06). In ENDO, all transporters were differentially abundant from days 16 to 50 of gestation (P ≤ 0.04), and SLC7A2 was greater (P = 0.05) for RES vs. CON. In SG, SLC7A1 and SLC7A2 were greater (P ≤ 0.04) at day 34 vs. day 16. In DG, SLC2A3 and SLC7A1 were greater (P ≤ 0.05) for CON vs. RES heifers; furthermore, SLC7A1 was greater (P < 0.01) at day 50 vs. days 16 and 34 of gestation. In MYO, SLC7A1 was greater (P < 0.01) for CON vs. RES and was greater (P = 0.02) at days 34 and 50 vs. day 16. There were no differences in FM (P ≥ 0.06). Analysis of all uterine tissues at day 16 determined that SLC2A1, SLC2A3, and SLC7A2 were all differentially abundant across uterine tissue type (P < 0.01), and SLC7A1 was greater (P = 0.02) for CON vs. RES. Analysis of all uteroplacental tissues at days 34 and 50 demonstrated that all transporters differed (P < 0.01) across uteroplacental tissues, and SLC7A1 was greater (P < 0.01) for CON vs. RES. These data are interpreted to imply that transporters are differentially affected by day of gestation, and that hexose and cationic amino acid transporters are differentially abundant across utero-placental tissue types, and that SLC7A1 is responsive to maternal nutritional treatment.  相似文献   
4.
枝干病害葡萄溃疡病近年来严重限制了葡萄产业发展。研究表明葡萄蔗糖转运蛋白参与寄主植物和病原菌的互作过程。为解析蔗糖转运蛋白VvSUC12在葡萄免疫反应过程中的功能,本研究克隆了VvSUC12基因翻译起始位点上游1 500 bp的启动子区,通过生物信息学分析发现该区域包含4个Dof转录因子结合序列(A/TAAAG)及多种激素调节与防御相关的顺式元件。实时荧光定量分析显示,接种可可毛色二孢菌显著诱导VvSUC12和VvDof19基因的表达。通过酵母单杂交实验筛选得到与VvSUC12启动子互作的转录因子VvDof19。酵母双杂交实验证实VvDof19具有自激活活性;进一步通过烟草瞬时表达发现Dof19-GFP的相对GUS活性约为对照GFP的9倍,表明转录因子VvDof19能够激活VvSUC12基因的表达。研究结果为深入研究蔗糖转运蛋白在葡萄免疫反应中的功能奠定基础。  相似文献   
5.
6.
为了解胶州湾海域鱼类群落粒径结构特征,本研究根据2016-2017年4次底拖网调查数据构建了胶州湾鱼类生物量粒径谱,比较分析了各季节鱼类生物量粒径谱特征参数的异质性。结果显示,胶州湾Sheldon型鱼类生物量粒径谱呈现单峰模式,鱼类粒径范围为-3~10粒径级,粒径分布相对均匀,且峰值位于5~6粒径级,主要由大泷六线鱼和褐菖鲉等小型鱼类构成。各季节鱼类标准化生物量粒径谱曲率和曲度差异显著,其中春季曲率最大且曲线较平缓,夏季曲率最小且曲线相对陡峭。谱线曲度和曲率的季节变化主要与粒径小的细纹狮子鱼、大泷六线鱼、玉筋鱼及长丝虾虎鱼等地方常栖性种类和赤鼻棱鳀、白姑鱼等季节洄游性种类的出现有关。Abundance-biomass comparison(ABC)曲线表明,春季处于未干扰状态,冬季处于中度干扰状态,夏秋季处于严重干扰状态。研究表明,胶州湾鱼类群落总体处于严重干扰状态,鱼类生物量谱呈现单峰型,粒径结构以小型粒径鱼类为主,且地方常栖性和季节洄游性鱼类等补充群体的数量和粒径大小影响鱼类生物量粒径谱的峰型和曲率。  相似文献   
7.
过氧化物酶体膜蛋白PMP是ABC转运蛋白ABCD亚家族蛋白之一,存在于过氧化物酶体膜上。研究表明,拟南芥中的ABCD亚家族ABC转运蛋白AtABCD1主要通过参与部分物质运输进入过氧化物酶体,其中包括茉莉酸合成的前体 OPDA。本研究通过RACE技术克隆了一个ABCD亚家族ABC转运蛋白基因HbPMP1,并进行表达分析。结果表明:HbPMP1全长4 011 bp,编码1 337个氨基酸残基,其表达产物与拟南芥AtABCD1有较高的相似性(氨基酸一致性为78%);该基因在伤害及外源茉莉酸诱导下  相似文献   
8.
针对目前农用运输车钢板弹簧选用不合理及用经验公式进行手工计算的低效率设计问题,分析了常用钢板弹簧的结构性能特点和适用范围。以多片等截面式和少片变截面式钢板弹簧为例,介绍了用计算机辅助设计方法进行钢板弹簧参数设计的步骤。最后用作者开发的计算机程序,对某1.0t级农用运输车的前悬架多片等截面钢板弹簧进行了参数设计,结果表明,用计算机辅助设计手段可大大提高钢板弹簧的设计效率。  相似文献   
9.
Systemicity of agrochemicals is an advantageous property for controlling phloem sucking insects, as well as pathogens and pests not accessible to contact products. After the penetration of the cuticle, the plasma membrane constitutes the main barrier to the entry of an agrochemical into the sap flow. The current strategy for developing systemic agrochemicals is to optimize the physicochemical properties of the molecules so that they can cross the plasma membrane by simple diffusion or ion trapping mechanisms. The main problem with current systemic compounds is that they move everywhere within the plant, and this non‐controlled mobility results in the contamination of the plant parts consumed by vertebrates and pollinators. To achieve the site‐targeted distribution of agrochemicals, a carrier‐mediated propesticide strategy is proposed in this review. After conjugating a non‐systemic agrochemical with a nutrient (α‐amino acids or sugars), the resulting conjugate may be actively transported across the plasma membrane by nutrient‐specific carriers. By applying this strategy, non‐systemic active ingredients are expected to be delivered into the target organs of young plants, thus avoiding or minimizing subsequent undesirable redistribution. The development of this innovative strategy presents many challenges, but opens up a wide range of exciting possibilities. © 2018 Society of Chemical Industry  相似文献   
10.
AIM: To study the expression of zinc transporter ZRT/IRT-like protein 14 (ZIP14) in the hepatocellular carcinoma (HCC) tissues, and to investigate the effects of ZIP14 over-expression on the biological behaviors of HCC cells. METHODS: The expression of ZIP14 at mRNA and protein levels in the HCC tissues and adjacent non-tumor tissues were detected by real-time PCR and immunohistochemical staining, respectively. The lentivirus expression system containing GV365-ZIP14 was constructed, and was used to infect the HCC cell line BEL-7404, which had relatively poor expression of ZIP14. The expression of ZIP14 at mRNA and protein levels in the transfected cells were detected by real-time PCR and Western blot, respectively. Under the conditions of zinc sulfate stimulation at different concentrations, the cell viability, the cell cycle, and the cell migration and invasion abilities were detected by MTT assay, DNA ploid detection, and Transwell assay, respectively. RESULTS: The mRNA expression level and the strong-positive rate of protein expression of ZIP14 in the HCC tissues were significantly lower than those in the adjacent non-tumor liver tissues (P<0.01). The expression of ZIP14 at mRNA and protein levels in the BEL7404 cells was significantly enhanced by infection of GV365-ZIP14 expression lentivirus. Compared with negative control group (transfected with negative control lentivirus), the cell viability, migration and invasion in ZIP14 over-expression group (transfected with GV365-ZIP14 expression lentivirus) were significantly reduced, and the percentage of the cells in G2/M phase was significantly increased, all of which were more obvious with the elevation of zinc concentration in the culture medium. CONCLUSION: ZIP14 is low expressed in the HCC tissues. The ZIP14 over-expression has inhibitory effects on the viability, migration and invasion of HCC cells, and blocks the cell cycle in G2/M phase, which might be closely related to the elevation of zinc concentration in cytoplasma of HCC cells due to enchanced zinc transport by ZIP14.  相似文献   
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