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101.
白背飞虱对水稻抗虫品种N22的适应性研究 总被引:2,自引:1,他引:2
在室内连续用感虫品种TN1和抗虫品种N22单管饲养白背飞虱(Sogatella furcifera)种群,研究它对抗虫水稻品种的适应性及其体内保护酶的变化,结果表明,白背飞虱在感虫品种TN1和抗虫品种N22品种上饲养1至2代,其卵历期、若虫期和全世代历期均无明显差异,从感虫品种TN1转移到抗虫品种N22上饲养1代,白背飞虱的若虫存活率、雌成虫寿命、体重、蜜露量、产卵量和内禀增长率等均低于在抗虫品种上连续饲养2代,而后者又低于在感虫品种上饲养的指标,白背飞虱在抗虫品种上连续饲养2代后,体内保护酶中超氧化物岐化酶(SOD)和过氧化氢酶(CAT)活性逐渐接近于感虫品种上连续饲养的结果,说明白背飞虱从感虫品种转到抗虫品种在开始时并不适应,经过连续繁殖多代后白背飞虱逐渐适应,最后导致抗虫品种的抗性丧失。 相似文献
102.
103.
一个新型耐热普鲁兰酶的结构与功能 总被引:1,自引:0,他引:1
新型普鲁兰酶的研究对于普鲁兰酶制剂的国产化、打破国外垄断具有非常重要的意义。从我国云南腾冲地区轮马热泉的淤泥中分离获得了一株耐热普鲁兰酶产生菌LM 18-11,经16S rDNA序列系统进化树分析,确定该菌为厌氧芽胞杆菌Anoxybacillus属种,并从中克隆获得了耐热普鲁兰酶的编码基因,该酶在55℃-60℃、pH 5.6-6.4的范围内具有最大的反应活性。此外,该酶具有较好的热稳定性,在60℃下处理48 h,仍可保持50%以上的活力;动力学分析该酶的Vmax和Km分别为750 U/mg和1.47 mg/mL,是目前文献报道中比活力最高的耐热普鲁兰酶。同时还对该酶进行了晶体结构分析,结果显示该酶具有?-淀粉酶家族中典型的结构,在N端具有一个特殊的底物结合域,该结构域的缺失导致比活力和底物结合力都有相应降低,Vmax和Km分别为324 U/mg和1.95 mg/mL。同时,将该普鲁兰酶编码基因导入枯草芽胞杆菌中,在P43启动子的控制下,普鲁兰酶基因获得了高效表达,胞外酶活可达42 U/mL,相比初始菌种,表达活力提高40倍以上。研究表明该普鲁兰酶具有很好的应用前景。 相似文献
104.
105.
Xiaohong Yang Dian Teguh Jian-Ping Wu Bo He Thomas Brett Kirk Shengnan Qin Siming Li Honghui Chen Wei Xue Benjamin Ng Shek Man Chim Jennifer Tickner Jiake Xu 《Arthritis research & therapy》2015,17(1)
IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users. 相似文献106.
Enhancement of Astragalus polysaccharide on the immune responses in pigs inoculated with foot-and-mouth disease virus vaccine 总被引:4,自引:0,他引:4
Li J Zhong Y Li H Zhang N Ma W Cheng G Liu F Liu F Xu J 《International journal of biological macromolecules》2011,49(3):362-368
The effects of Astragalus polysaccharides (APS) on the immune response in pigs immunized with foot-and-mouth disease virus (FMDV) vaccine were investigated. Fifteen pigs were randomly divided into five groups. Four groups were vaccinated with a FMDV inactivated vaccine. Pigs in three experimental groups were administered varying doses of APS (APS1, 5 mg/kg; APS2, 10 mg/kg; APS3, 20 mg/kg). The influence of APS on the number of CD3+CD4−CD8+ cytotoxic T cells, CD3+CD4+CD8+ T helper memory cells, and CD3−CD4−CD8+ natural killer cells among peripheral blood lymphocytes (PBL) in the three APS groups were significant compared to the vaccine group. In vitro stimulation of PBL by Con A and LPS in APS groups induced a stronger proliferative response at 2 and 6 weeks post-inoculation (PI). APS markedly increased the titer of FMDV-specific antibody in a dose-dependent manner, and up-regulated mRNA expression of IFN-γ and IL-6. APS could potentially be used as an immunomodulator for a FMDV vaccine and provide better protection against FMDV. 相似文献
107.
稻米垩白形成的气象生态基础研究 总被引:13,自引:0,他引:13
在全国13个点、19个品种多播期试验基础上,对稻米垩自形成的气象生态基础进行了分析。结果表明,水稻齐穗后15天的日均温是影响稻米垩白大小的主要气象因子。经对稻米垩白与齐穗后15天内均温关系的动态分析可知,稻米垩白随该时段温度提高而增大的拐点温度约为29℃(品种间略有差异),接近或超过该点温度,稻米垩白会突发性地增加。 相似文献
108.
因子分析和聚类分析在玉米品种资源分类上的应用 总被引:5,自引:0,他引:5
本研究对201份湖北省玉米品种资源的28个性状进行了因子分析,结果前7个公因子对变异的累计方差贡献率达79.4%,前7个独立的公因子真实地反了所控制的28个性状及其相互关系.以前7个公因子为综合指标进行系统聚类,201份玉米品种聚成12类,其中A,B,H,K类综合性状较好. 相似文献
109.
Metallothioneins MTT1 and MTT2 from Tetrahymena thermophila have been characterized. The MTT1 contains mainly characteristic Cys-Cys-Cys and Cys-Cys clusters, but MTT2 contains mainly Cys-X-Cys cluster. Cd16-MTT1 mainly consists of α-helix and β-turns, in contrast, Cd11-MTT2 mainly consists of random coils. Reaction of Cd16-MTT1 and Cd11-MTT2 with nitric oxide leads to intramolecular disulfide bond formation, respectively. Binding stabilities of Cd2+, Hg2+ and Zn2+ to MTT1 are stronger than those to MTT2. Cu2+ can not replace Cd2+ from Cd16-MTT1 complex, but can replace Cd2+ from Cd11-MTT2 complex. The analysis of qRT-PCR revealed MTT2 mRNA levels were 31-fold higher than those of MTT1 under basal conditions. These results further suggest MTT1 possibly play a role in the detoxification of heavy metal ions, and MTT2 may be involved in the homeostasis of copper ions. 相似文献
110.
Feiyu Jia Chongxi Liu Xiangjing Wang Junwei Zhao Qianfeng Liu Ji Zhang Ruixia Gao Wensheng Xiang 《Antonie van Leeuwenhoek》2013,103(2):399-408
A novel endophytic actinomycete, designated strain NEAU-J3T, was isolated from soybean root (Glycine max (L.) Merr) and characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain NEAU-J3T fell within the family Micromonosporaceae. The strain was observed to form an extensively branched substrate mycelium, which carried non-motile oval spores with a smooth surface. The cell walls of strain NEAU-J3T were determined to contain meso-diaminopimelic acid and galactose, ribose and glucose were detected as whole-cell sugars. The major menaquinones were determined to be MK-9(H4) and MK-9(H6). The phospholipids detected were phosphatidylcholine and phosphatidylethanolamine. The major cellular fatty acids were determined to be C16:0, C18:1 ω9c, C18:0, C17:0, C17:1 ω7c, anteiso-C17:0, C16:1 ω7c and C15:0. The DNA G + C content was 62.5 mol%. On the basis of the morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-J3T is considered to represent a novel species of a new genus within the family Micromonosporaceae, for which the name Wangella harbinensis gen. nov., sp. nov. is proposed. The type strain of Wangella harbinensis is strain NEAU-J3T (=CGMCC 4.7039T = DSM 45747T). 相似文献