大豆吡哆醇生物合成蛋白基因(PDX)的电子克隆和进化分析

电子克隆(In silicocloning)是随着基因组计划和EST计划实施而发展起来的利用生物信息学手段进行基因克隆的新方法。根据物种间同源基因相对保守的特点,以拟南芥(Arabidopsis thaliana)吡哆醇生物合成蛋白cDNA序列为信息探针,对大豆(Glycine max)EST数据库进行同源搜索和序列拼接,获得了1 280 bp长的大豆吡哆醇生物合成蛋白的基因序列(GenBank登陆号为DQ139265)。经过RT-PCR扩增、基因组PCR扩增、分子克隆和序列分析验证,结果表明与电子克隆序列完全一致。该基因具有完整的开放阅读框架(ORF,20~955 bp),编码311个氨基酸。通过与水稻、日本百脉根、烟草、截形苜蓿等物种的吡哆醇生物合成蛋白序列比对,发现该基因具有高度的保守性。表明根据物种间同源基因序列,对跨物种间EST数据库进行同源检索、筛选、拼接,是克隆基因的有效途径。     

U-box蛋白质的结构及其功能研究进展

泛素系统是选择性降解细胞内蛋白质的重要系统之一,U-box蛋白质是此系统中决定底物特异性识别的一种新型E3蛋白质,部分U-box蛋白质属于泛素链聚集因子-E4。U-box结构域大约由70个氨基酸残基构成,在酵母、植物和动物等真核生物中保守存在,但植物中的数目远多于动物中。该蛋白质在细胞内异常蛋白质的降解及质量控制方面具有重要的作用,了解U-box蛋白质的功能对疾病的发生控制机理有重要意义。     

荞麦种子蛋白质组分分析

研究了不同品种荞麦种子中蛋白质组分情况，结果表明：养麦种子蛋白质主要由清蛋白、球蛋白、谷蛋白和醇溶蛋白构成。而不同类型蛋白质在总蛋白质中所占比例有明显差异，清蛋白是荞麦种子中的主要蛋白质，占总蛋白质含量的71．4％左右，其中以平荞最高。醇溶蛋白在荞麦种子总蛋白中所占比例较小，平均约为7．4％，榆养2号最高。球蛋白和谷蛋白所占比例非常接近，其中球蛋白平均约占9．1％，最高为日本大粒养。谷蛋白大约占总蛋白的12．1％，以京养1号最高。     

陆地棉一个丝氨酸/苏氨酸激酶蛋白基因的克隆与表达分析

通过RT-PCR获得一个编码棉花丝氨酸/苏氨酸激酶类似蛋白全长的cDNA片段,其编码的氨基酸序列与拟南芥ATPK3的相似度达到82%,这个基因暂被命名为GhPK1。基因全编码区包括1038个核苷酸,编码346个氨基酸的蛋白。GhPK1的编码产物在265~270个氨基酸处有一个跨膜区并可能结合在内质网膜上。GhPK1在种子和纤维中的表达水平较其它组织高。另外,GhPK1的表达量在受到盐胁迫后上升,说明GhPK1可能参与了盐胁迫反应。     

Genotypic variability in vegetable amaranth (Amaranthus tricolor L for foliage yield and its contributing traits over successive cuttings and years

Summary Twenty nine strains of vegetable amaranth (Amaranthus tricolor were grown for two successive seasons to study different selection parameters for foliage yield and its nine contributing morphological and quality traits. The strains AV-38 (5.06 kg/plot) and AV-31 (5.04 kg/plot) recorded highest foliage yield, followed by AV-30 (4.78 kg/plot) and AV-23 (4.70 kg/plot). The protein and carotenoid content averaged 1.24 ± 0.03 mg/100 mg and 0.83 ± 0.02 mg/g respectively. The leaves of A. tricolor also have considerable quantities of ascorbic acid (112.33 ± 5.00 mg/100 g) and fibre (8.39 ± 0.10%). The mean of individual cuttings for plant height, leaf size, stem diameter, foliage yield, protein, ascorbic acid and fibre content increased with successive cuttings till third cutting and thereafter showed a decline. Genotypic coefficient of variation (GCV) values ranged from 6.80 to 28.25%. However, the fibre content, branches/plant, leaves/plant, plant height and stem diameter showed lowest values of GCV. The values of heritability estimates were high for all the traits in all the cuttings as well as on pooled basis and ranged from 0.89 for branches/plant to 0.98 for foliage yield. Highest expected genetic advance was noticed for ascorbic acid (57.48%), followed by foliage yield (48.30%) and leaf size (29.51%).     

Growth and Yield Response of Facultative Wheat to Winter Sowing, Freezing Sowing and Spring Sowing at Different Seeding Rates

Growth and yield of wheat are affected by environmental conditions and can be regulated by sowing time and seeding rate. In this study, three sowing times [winter sowing (first week of September), freezing sowing (last week of October) and spring sowing (last week of April)] at seven seeding rates (325, 375, 425, 475, 525, 575 and 625 seeds m^?2) were investigated during the 2002–03 and 2003–04 seasons, in Erzurum (Turkey) dryland conditions, using Kirik facultative wheat. A split‐plot design was used, with sowing times as main plots and seeding rates randomized as subplots. There was a significant year × sowing time interaction for grain yield and kernels per spike. Winter‐sown wheat produced a significantly higher leaf area index, leaf area duration, spikes per square metre, kernel weight and grain yield than freezing‐ and spring‐sown wheat. The optimum time of sowing was winter for the facultative cv. Kirik. Grain yields at freezing and spring sowing were low, which was largely the result of hastened crop development and high temperatures during and after anthesis. Increasing seeding rate up to 525 seeds m^?2 increased the spikes per square metre at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as sowing time in maximizing grain yield. Changes in spikes per square metre were the major contributors to the grain‐yield differences observed among sowing times and seeding rates. Yield increases from higher seeding rates were greater at freezing and spring sowing. We recommended that a seeding rate of 525 seeds m^?2 be chosen for winter sowing, and 575 seeds m^?2 for freezing and spring sowing.     

Caco-2细胞模型及其在食品营养物质吸收研究中的新进展

概述了Caco-2细胞系的特点、模型的建立与验证,及其在营养物质吸收及机制研究中的新进展。并评价了将Caco-2细胞用于营养物质吸收转运中的优点与局限性。     

桑叶叶蛋白提取工艺的研究

探讨桑叶叶蛋白提取的工艺条件。结果表明,桑叶叶蛋白提取的最佳工艺条件为:在温度60℃下,以质量分数0.7%的NaOH溶液为浸提剂,浸提时间20min,料液比为1∶4,絮凝温度75℃,叶蛋白提取率为4.42g/100g。     

Prediction of grain protein in spring malting barley grown in northern Europe

The ability to predict grain protein concentration at harvest (CP) in Swedish malting barley (Hordeum distichum) from observations of soil conditions, sowing day, fertilisation rate, remote sensing at early stem elongation and the temperature sum during grain filling, was tested for two cultivars; Astoria (Secobra, France) and Wikingett (Svalöf-Weibulls, Sweden) in 16 fertilisation trials in southern Sweden, encompassing 3 years (2001–2003). Fertilisation was applied either as a single dose at sowing, or as both a starting application and an application at early stem elongation. The highest total application rate was 160 kg N ha⁻¹ y⁻¹. The soil was analysed for phosphorus, potassium, magnesium and calcium in the layer 0–0.3 m, and mineral N down to 0.6 m. Canopy reflectance observations at BBCH 32 was used to calculate a vegetation index (TCARI(32)) to reflect the canopy (leaf and straw) chlorophyll concentration. Harvested grain CP correlated only marginally with the observed soil variables. It was, however, for a specific cultivar, possible to make a prediction of grain CP based on day of sowing and TCARI(32) with . Part of the sowing day effect might be due to thermal stress during grain filling, as the risk for high temperatures during this phase was higher when sowing was late. This might also explain why the introduction of accumulated temperature during grain filling, into a model already including sowing day and TCARI(32) as independent variables, did not improve the predictability of grain CP.     

FMDV OA/58病毒株VP1蛋白结构构建与B细胞抗原表位的预测

以口蹄疫病毒株OA/58 RNA为模板,反转录并扩增目的cDNA,然后与pGEM-T easy载体连接并转化JM109菌株,提取的重组质粒用凝胶电泳、PCR和EcoR Ⅰ酶切法鉴定.运用同源模建得到OA/58 VP1蛋白3D结构,并结合理化性质、亲水性、可塑性和免疫原性进行分析,预测OA/58 VP1的抗原表位.结果 OA/58 VP1存在多个潜在的抗原表位位点,可能的蛋白质抗原表位区域:2～11,15～35,38～50,77～88,90～107,121～125,131～135,140～149,154～163,169～175,178～189,197～213.应用同源模建得到的OA/58 VP1蛋白3D模型来预测其B细胞表位,为进一步研究OA/58 VP1功能,构建突变体和选择表达新型OA/58 VP1蛋白分子提供有参考价值的信息.