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植物病毒卫星核酸是已知的最小的侵染因子之一,其起源、致病性以及复制机制一直都是研究的热点。目前研究认为,植物病毒卫星核酸最有可能来源于寄主植物基因组或辅助病毒基因组,植物病毒卫星核酸、辅助病毒及寄主三者相互作用对辅助病毒的积累量及寄主病症的发展有调节作用。植物病毒卫星核酸不能自我复制,它们依赖于辅助病毒进行复制,然而,由于结构不同它们的复制方式也不完全相同。自发现以来,这类小的亚病毒分子已成为研究植物细胞中大分子间的互作及其辅助病毒复制机制的简单模型。本文主要总结了植物病毒卫星核酸在复制机制、起源、致病性及应用方面取得的研究进展。 相似文献
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芜菁花叶病毒研究进展 总被引：2，自引：1，他引：2
近10余年来,芜菁花叶病毒(TuMV)分子生物学研究取得了显著进展.大量TuMV株系核酸全序列和部分序列的分析,增加了人们在核酸分子水平上对TuMV遗传、变异和进化的认识.TuMV株系核酸序列较大的变异性与病毒广泛寄主范围是一致的,核酸重组加快了TuMV的变异和进化.通过研究油菜、大白菜对TuMV的抗性,发现了株系专化性和广谱性两类抗性,其中一些抗性基因已被定位在遗传图谱上,为其进一步克隆提供了条件.将作物自身抗性和转基因抗性相结合,获得对TuMV广谱而持久性抗性,是研究工作者为之奋斗的目标. 相似文献
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核酸是生物体内的大分子化合物,是遗传信息的载体,“主宰”着生物体内蛋白质的生物合成,从而控制着生物的生长、发育、遗传和变异。笔者对茶叶中核酸的测定方法进行了探索,在此基础上测定了不同等级茶中核酸的含量,现就已定的方法和有关测定结果作一介绍。一、方法的选定核酸测定的方法,一般有定磷法、戊糖比色法以及紫外分光光度法三种,作者选用了紫外分光光度法。试验结果表明,这种方法比前两种方法简易,准确,重复性好,因此选定为测定茶叶中核酸的方法。 1.测试样的前处理 (1)除杂质:称取3.0000克磨碎茶样放入研钵 相似文献
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近年来,随着转基因技术的快速发展和我国转基因产业化应用的不断推进,对我国农业转基因生物安全监管工作提出了更高的要求。为更好地满足监管工作需求,转基因快速检测技术的研究与应用尤为重要。本文从基于核酸水平的快速检测技术、基于蛋白水平的快速检测技术和其它快速检测技术三个方面,介绍了核酸快速提取技术、核酸恒温扩增技术、核酸试纸条技术、免疫层析试纸条技术和生物传感器等重要技术的原理、研究进展、优缺点及应用情况。总结分析了转基因生物成分快速检测技术发展趋势、应用前景以及亟需解决的难点问题,以期促进我国转基因产品快速检测技术发展,为我国农业转基因生物安全监管工作提供有效支撑。 相似文献
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采用α-32P标记的三磷酸核苷酸与病毒粒子共浴的方法及Northwestern分子杂交方法,研究证明了RGDV结构蛋白中,P1蛋白可能是依赖于RNA的RNA聚合酶, P5蛋白可能具有RNA鸟苷酰转移酶功能,P6蛋白可能是核酸结合蛋白,是RGDV复制包装中的关键蛋白。与RGDV结构蛋白具有相同生物功能的RDV的核酸结合蛋白与核酸的结合能力最强,依赖于RNA的RNA聚合酶与核酸的结合能力次之,RNA鸟苷酰转移酶与核酸的结合能力最弱。结果暗示了可以根据与核酸的结合能力,辅助判断RDV或RGDV这3个结构蛋白的生物功能。 相似文献
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"大豆核酸露"是采用先进的生物工程技术"从大豆植物细胞中萃取核酸",并以大豆母液为载体的功能性基因营养饮料.日本生化学家诺贝尔奖金获得者利根川进发出了人类所有的疾病都与基因受损有关,而核酸却具有修复基因的特殊功能.体内核酸缺乏,将导致新陈代谢失常,正常细胞变异,机体早衰和病变. 相似文献
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橡胶树胶乳的核酸调控着腕乳的再生过程，胶乳的产量与其核酸含量呈正相关。死上以的形成与胶乳核酸含量及核酸酶活性的变化具有一定的联系。割胶和乙烯利刺激表现出相似的生理效应，可诱导胶树产丙源乙烯，并对有关基因表达活性的调节，促进胶乳的核酸和蛋白质（酶）的生物合成过程，从而提高胶乳的再生能力及产量。 相似文献
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Ali Debo Thabèt Yangui Abdelhafidh Dhouib Moheiddine Ksantini Sami Sayadi 《Crop Protection》2011,30(12):1529-1534
Olive mill wastewater (OMW) is a problematic by-product in Mediterranean countries. Despite this, it is a raw material that is an unfailing source of bioactive molecules. A hydroxytyrosol-rich preparation (HRP) (49.6% weight:dry weight) was extracted from fresh OMW using a hydrolysis and post-hydrolysis purification process. The field efficacy of HRP as a spray treatment (2500 l ha−1) against olive psyllid, Euphyllura olivina (Hemiptera: Psyllidae), was evaluated in 2008 and 2009 in a drip-irrigated olive orchard.The HRP showed strong insecticidal activity against E. olivina at a concentration of 2 g l−1 hydroxytyrosol. Application of HRP resulted in 41.1 and 72.1% control of nymphs and adults, respectively. However, HRP application did not reduce egg hatch. Neither phytotoxicity nor toxicity to auxiliary-fauna was recorded with concentrations of 1.25 g l−1 or 2 g l−1 HRP. But, the 2.5 g l−1 concentration was slightly phytotoxic, especially at the E and F floral phenological stages of the grapes. HRP offers a natural and effective extract for control of olive psyllid and opens a new opportunity for the reuse of OMW. 相似文献
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水稻SSR不同检测和分析方法的比较研究 总被引：23，自引：0，他引：23
用15对水稻微卫星引物,对13个不同类型及来源的水稻基因型材料进行了简单序列重复片段长度的多态性(SSLPs)分析,并与不同的检测和分析方法进行了比较。聚丙烯酰胺凝胶电泳无论是放射性自显影分析还是荧光标记的自动测序仪分析都比高密度的琼脂糖电泳(3% MetaPhor agarose)有效。利用荧光标记自动测序系统的SSLPs分析较之传统的32P标记的聚丙烯酰胺凝胶电泳分析,具有以下优点：(1)借助于荧光染料标记的丰富内标,可以区别几个bp之差的SSLPs ;(2)借助于不同的荧光标记可以在同一样孔里分析多个样品;(3)自动给出SSLPs片段的长度;(4)自动的数据输出和分析;(5)避免了放射性同位素有可能造成的环境污染。因此,该方法具有快速、高效的特点。 相似文献
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用同位素~(14)C 示踪法研究了秋冬季茶树同化产物的积累与分配。结果表明,茶树在秋冬季仍有较大的光合作用能力,其同化产物以向基运贮为主,秋标记~(14)C-同化产物至初春,留存在根、茎部占其总量的83.4%,冬标记占75.5%,茶树光合产物的积累秋标高于冬标,秋标至初春树体内的~(14)C-同化产物保留有54.5%,冬标只保留了38.8%,因此,加强秋冬季茶园管理,增加树体养分积累,是保证来年茶叶高产优质的重要技术措施之一。 相似文献
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Background: Phenylalanine dehydrogenase (PheDH; EC 1.4.1.20) is a NAD+-dependent enzyme that performs the reversible oxidative deamination of L-phenylalanine to phenylpyruvate. It plays an important role in detection and screening of phenylketonuria (PKU) diseases and production of chiral intermediates as well. The main goal of this study was to find a simple and rapid alternative method for purifying PheDH. Methods: The purification of recombinant Bacillus sphaericus PheDH was investigated in polyethylene glycol (PEG) and ammonium sulfate aqueous two-phase systems (ATPS). The influences of system parameters including PEG molecular weight and concentration, pH and (NH4)2SO4 concentration on enzyme partitioning were also studied. The purity of enzyme was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Results: A single extraction process was developed for separation and purification of recombinant PheDH from E. coli BL21 (DE3). The optimized conditions for partitioning and purification of PheDH were 9% (w/w) PEG-6,000 and 16% (w/w) (NH4)2SO4 at pH 8.0. The partition coefficient, recovery, yield, purification factor and specific activity values were achieved 58.7, 135%, 94.42%, 491.93 and 9828.88 U/mg, respectively. Also, the Km values for L-phenylalanine and NAD+ in oxidative deamination were 0.21 and 0.13 mM, respectively. Conclusion: The data presented in this paper demonstrated the potential of ATPS as a versatile and scaleable process for downstream processing of recombinant PheDH. 相似文献
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以受黄曲霉毒素B_1(aflatoxin B_1,AFB_1)污染的米糠为原料,研究微波辅助酶法对米糠中AFB_1脱除效果的影响。初始米糠中AFB_1浓度为102.54μg/kg,以料液比(g∶m L)1∶10、加酶量0.50%、α-淀粉酶和纤维素酶酶解液pH6.0、温度50℃、处理时间2 h的工艺条件制备米糠蛋白。结果表明,米糠中AFB_1残留浓度为56.03μg/kg(脱除率为45.36%),米糠中蛋白质回收率为78.20%;基于该工艺研究,在单位体积微波功率750 W和处理时间10 min的条件下,由酶法提取的米糠蛋白制品中AFB_1残留浓度为4.21μg/kg(脱除率为92.48%),符合国家标准(≤10μg/kg),而蛋白质回收率达到81.36%。本研究采用免疫亲和柱净化结合HPLC-FLD检测法,提高AFB_1的检出限至0.10μg/kg。微波处理不仅对米糠蛋白中AFB_1有明显的脱除效果,且有利于蛋白回收率的提高。该法操作简单,脱除效率高,可应用于受黄曲霉毒素污染的米糠制品中。 相似文献
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An isolation and purification procedure for wheat high molecular weight glutenin subunits (HMW-GS) involving no steps expected to cause deglycosylation of glycoproteins was developed to allow removal of the maximum amount of carbohydrates not covalently linked to HMW-GS. Flour was defatted and then extracted with 50%n-propanol (50%n-PrOH) to remove arabinogalactans and glucose-containing material. HMW-GS were extracted with 50%n-PrOH containing 5% β-mercaptoethanol, precipitated in 60%n-PrOH, alkylated and recovered by precipitation. The partially purified HMW-GS were separated by cation exchange chromatography and resulting fractions purified by RP–HPLC. The purified HMW-GS contained only 0·1% of glucose (corresponding to 51–59 monosaccharide residues per 100 HMW-GS molecules) and no other amino or neutral sugars. The HMW-GS gave a positive reaction in a periodate–digoxigenin glycan detection assay when labelled in solution (with or without periodate oxidation) but not when labelled directly on-the-blot. HMW-GS expressed inEscherichia coli, a micro-organism without glycosylation capabilities, reacted in an identical way. Possible reasons are given for the difference in results obtained after labelling in solution or on-the-blot. No positive reaction between the purified HMW-GS and mannose-specificGalanthus nivalisagglutinin was observed. The presence of N-acetylglucosamine in HMW-GS has been previously reported20. Since neither mannose nor N-acetylgalactosamine were found in the HMW-GS, and these proteins lack the sequon necessary for N-glycosylation, only O-linked GlcNAc moieties are possible. This modification could not be detected using a galactosyltransferase labelling assay. Taken together these results suggest that HMW-GS are not glycosylated. 相似文献
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以碳酸锰、脲、柠檬酸、双氧水为原料,采用微波加热法合成具有纳米模拟酶催化活性的锰掺杂碳点(Mn-CDs)。Mn-CDs可催化3,3’,5,5’-四甲基联苯胺(TMB)产生蓝色的ox-TMB。乙酰胆碱酯酶(AChE)催化底物乙酰硫代胆碱(ATCh)生成的硫代胆碱(TCh),还原所生成的ox-TMB使溶液蓝色褪去。有机磷类农药能有效抑制AChE的活性,使TCh的生成量减少,溶液的蓝色变深。根据吸光度的变化可以定量检测有机磷农药含量,由溶液颜色的深浅可以构建毒死蜱的可视化半定量检测方法。本研究表征了Mn-CDs的表面结构及微观形貌,以有机磷类农药主要品种毒死蜱作为分析模型,初步探讨了比色法检测毒死蜱的原理;考察了毒死蜱检测的最优条件,检测的线性范围是0~3.5μg/mL,检测限为0.013μg/mL。将该检测方法用于苹果实际样品中毒死蜱的测定,回收率为95.2%~102.8%,表明该方法有望应用于实际样品中有机磷的高灵敏测定。 相似文献
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To image inflammation sites, we developed a novel nanoparticle, hydroxylamine-containing nanoparticle (HANP), which emits an intense electron spin resonance (ESR)-signal triggered by enzymatic oxidation reaction and pH-sensitive self-disintegration. The nanoparticle was prepared from an amphiphilic block copolymer, poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-hydroxyl)aminomethylstyrene] (PEG-b-PMNT-H), which spontaneously forms a core-shell type polymeric micelle (particle diameter = ca. 50 nm) in aqueous media. Because the PMNT-H segment in the block copolymer possesses amino groups in each repeating unit, the particle can be disintegrated by protonation of the amino groups in an acidic pH environment such as inflammation sites, which is confined to the hydrophobic core of HANP. Mixing HANP with horseradish peroxidase (HRP)/H(2)O(2) mixture resulted in enzymatic oxidization of the hydroxylamines in the PEG-b-PMNT-H and converted the hydroxylamine to the stable nitroxide radical form in PEG-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)aminomethylstyrene] (PEG-b-PMNT), which shows an intense ESR signal. It is interesting to note that the ESR signal increased at a greater rate under acidic conditions (pH 5.6) than that under neutral conditions (pH 7.4), although the enzymatic activity of HRP under neutral conditions is known to be much higher than that under acidic conditions. This indicates that enzymatic oxidation reaction was accelerated by synchronizing the disintegration of HANP under acidic conditions. On the basis of these results, HANP can be used as a high-performance ESR probe for imaging of inflammation sites. 相似文献