酸性磷酸酶在萌发大豆种子中子叶细胞壁上的分布

本文应用光镜，电镜酸性磷酸酶的细胞化学定位法，对大豆种子萌发过程中酸性磷酸酶在子叶细胞壁上的分布进行了详细的观察与分析。大豆种子吸水膨胀１天时，子叶细胞的胞间层首先表现出酸性磷酸酶的活性；播种１－２天后，除胞间层外，胞间隙也表现了酸性磷酸酶的活性；播种４－６天期间，酸性磷酸酶不仅在胞间层，胞间隙处表现出活性，而且在细胞壁及质膜上也表现出较强的活性。根据本文的观察结果我们推测，萌发的大豆子叶细胞壁上     

淹水胁迫下水稻根尖细胞中Ca^2＋和Ca^2＋—ATP酶的分布

应用电镜细胞化学方法，对淹水胁迫下水稻根尖细胞中Ca^2 和Ca^2 -ATP酶分布的变化进行了观察。正常生长条件下，Ca^2 主要分布于液泡和细胞间隙中，而细胞质基质、细胞核中分布很少；Ca^2 －ATP酶主要分布于质膜上，线粒体膜、内质网膜、核膜上也有酶分布。经过没顶淹水处理后，液泡、细胞间隙中的Ca^2 沉淀颗粒明显减少，而胞质及核基质中的沉淀颗粒明显增多，同时，质膜及其他膜结构上Ca^2 －ATP酶的活性明显降低。淹水造成根尖细胞中Ca^2 －ATP酶活性降低，胞质和核基质中Ca^2 积累，将影响细胞的正常生理代谢活动。     

水稻CMS产量组分的核质互作遗传效应研究

对不育系的遗传构成的剖析表明，不育系一般配合力由不育胞质配合力，不育胞核配合力和核质互作配合构成；不育胞质基因组通过胞质配合力，与不育胞核的互作，与恢复胞核的互作以及与不育胞核和恢复系的二级作四种遗传机制影响杂交稻组合性状的表现，供试三种不育胞质基因组有产量组分配合力上的差异，以Ｋ型胞质产量组分配合力较好，胞质配合力在不育系配合力构成中随性状的不同有０－５１％的相对重要性，进一步提高不育系的配合力     

不同基因型甜菜根际酸性磷酸酶动力学参数研究

采用液培法，对5个基因型甜菜品种（系）根表酸性磷酸酶的动力学特征进行了研究，结果表明：①根表酸性磷酸酶的水解反应基本符合Michaelis-Menten方程，可以用其对酶的水解过程加以描述；②各品种f系）根表酸性磷酸酶的水解动力学特征可以通过Lineweaver-Burk、Hanes和Edie-Hofstee方法对Michaclis-Menten方程进行转换和线性拟合，但方程Edie-Hofstee的拟合更切合实际：③甜菜的根表酸性磷酸酶是由两个酶系统，即酶系统Ⅰ和酶系统Ⅱ共同组成，在底物浓度较低时，水解速率由酶系统Ⅰ控制，而在底物浓度较高时，由酶系统Ⅱ控制；④不同基因型甜菜的根表酸性磷酸酶的动力学参数存在较大差异。     

小麦染色体转入黑麦的研究进展

十多年来，德国的Ｓｃｈｌｅｇｅｌ和Ｍｅｌｚ等人从进行黑麦改麦改良的目的出发，致力于将小麦染色体转入黑麦的工作，已获得具有１０个小麦细胞质的黑麦－小麦附加系，８个具有黑麦胞质的黑麦—小麦附加系。这些附加系在形态上与黑麦基本相似，其生活力因胞质的不同；具有小麦胞质的附加系生活力弱，分蘖少，结实性差；具有黑麦胞质的附加系生活力、分蘖性基本正常，结实性亦较好。在小麦染色体的传递性方面。两种胞质的附加系都表     

植物紫色酸性磷酸酶的研究进展

酸性磷酸酶（APase）是酸性条件下（pH < 7.0）能催化磷酸单酯或酸酐裂解从而释放无机磷酸根离子的水解酶类。紫色酸性磷酸酶（Purple acid phosphatase,PAP）是一类特殊的酸性磷酸酶,其具有鲜明的特征,如：酶的提取液呈紫色或粉色、酶活性不受酒石酸盐抑制、氨基酸序列具有5个保守结构域和双金属离子催化中心等。已有的研究表明,紫色酸性磷酸酶在植物适应低磷胁迫过程中发挥着重要作用。本文综述了紫色酸性磷酸酶的生化特性、亚细胞定位、生物学功能以及最新研究进展。     

甘蓝型油菜不育细胞质遗传效应的研究

Ｐｏ１ＣＭＳ、Ｓ２Ａ和ＭＩＣＭＳ三种不育细胞质遗传效应的研究结果表明，油菜不育胞质对杂种一代主要农艺性状表现负效应趋势．但不同来源的胞质在不同性状上的遗传效应有明显的组合特异性，其遗传效应不仅与不育胞质的类型有关．还和保持系、恢复系的核基因及其互作有关。在所研究的核背景下，Ｐｏ１ＣＭＳ不育胞质的遗传效应明显优于Ｓ２Ａ和ＭＩＣＭＳ。通过选用优良不育胞质和合理选配组合，可以把不育胞质的负效应降到最小限度。     

小麦染色体转入黑麦的研究进展

十多年来，德国的Ｓｃｈｌｅｙｅｌ和Ｍｅｌｚ等人从进行黑麦改良的目的出发，致力于将小麦染色体转入黑麦的工作，已获得具有１０个小麦胞质的黑麦－小麦附加系，８个具有黑麦胞质的黑麦－小麦附加系。这些附加系在形态上与黑麦基本相似，其生活力因胞质的不同：具有小麦胞质的附加系生活力弱，分蘖少，结实性差；具有黑麦胞质的附加系生活力、分蘖性基本正常，结实性亦较好。在小麦染色体的传递性方面，两种胞质的附加系都表现低频率。利用获得的附加系，定位了３个小麦基因：控制叶茎部紫色性状的基因Ｒａ２和Ｒａ３分别位于４Ｂ和６Ｂ上；控制过氧化氢酶的Ｃａｔｌ位点位于４ＢＬ上；对Ｐｈ１基因在黑麦传递背景下的表达进行了研究，Ｐｈ１对黑麦染色体的配对具有抑制作用。另外，采用辐射手段进行了染色体的易位研究，将６ＢＬ易位到黑麦染色体组上，此项工作是在二倍体水平上进行染色体工程操作的一个新探索。     

甜菜根际磷酸酶分泌特性的研究

甜莱根际磷酸酶的分泌特性是其根际土壤中有机磷有效性的决定性因子。采用液体培养和改进的Kuchenbuch微型盒土培法。对甜莱根际磷酸酶的分泌情况进行了较详细的研究。结果表明：(1)甜莱对有机磷的吸收是以有机磷的分解转化为前提，不同基因型的甜莱根际产生磷酶的种类、分布范围及分泌总量存在明显差异。并表现在对有机磷胁迫的抗耐能力方面的差别。某些基因型对有机磷表现出极强的分解、吸收和适应能力；(2)甜莱根系可分泌出多种磷酸酶。其中绝大多数品种以酸性磷酸酶为主。其次是中性磷酸酶．而碱性磷酸酶几乎没有；(3)甜莱各品种(系)根际磷酸酶的分布均表现出从根表向根际以外逐渐由高到低的特点。当达到一定点趋于一个恒定的值，符合方程y=yo ae^(-bx)的分布规律。     

棉属九个种同核异质系的培育与研究

50年代以后,异源胞质遗传研究广泛开展。但最早的研究大多是通过正反交差异比较来确认异源胞质的遗传效应,尽管在一定程度上排斥了核基因组差异的影响,但这种差异并不一定是真实的胞质效应,它还可能包括母体效应、持久性饰变及供质种胞质和     

孕穗期施氮对小麦蛋白质组分积累和蛋白质体发育的影响

为了揭示氮素对小麦蛋白质品质的调节效应,以扬麦9号为材料,研究了孕穗期施氮对小麦籽粒蛋白质组分积累及胚乳细胞蛋白质体发育的影响.结果表明:(1)随花后天数的增加,小麦籽粒清蛋白含量呈现由高到低的变化,球蛋白含量先下降,后期又升高;而醇溶蛋白和麦谷蛋白含量基本呈现由低到高的变化;(2)孕穗期施氮能显著提高醇溶蛋白和麦谷蛋白含量,而对清蛋白和球蛋白含量影响较小;(3)小麦胚乳细胞中蛋白质体约在花后12 d出现,花后16 d蛋白质体开始大量合成,其数目迅速增多,体积变大.成熟后期,蛋白质体因胚乳细胞中大小淀粉体的充实被挤成片层结构而填充在淀粉体缝隙中.胚乳边缘细胞中蛋白质体大而多,中部细胞蛋白质体小而少;(4)孕穗期施氮可促进蛋白质体的形成,使其数目增多.     

Transition from vitreous to floury endosperm in maize (Zea mays L.) kernels is related to protein and starch gradients

Relationships between kernel vitreousness and proteins and starch partitioning to the floury and vitreous regions of the endosperm were monitored in a set of 13 maize inbred lines. Decrease of protein contents from the vitreous to the floury endosperms were mainly assigned to α-zeins. Using Raman microspectroscopy, we observed a protein gradient from the periphery to the center of endosperms that well fitted with the inverse relationships between vitreousness and protein content of the vitreous and floury regions. In addition, Raman microspectroscopy highlighted an increase of starch crystallinity from the periphery to the center of the maize endosperms. This agrees with the higher amylose and associated lipid contents within starches of vitreous than in those of floury endosperms. Finally, starch granules from vitreous regions displayed more channels than the floury ones. These channels contain proteins that might favor adhesion of proteins to starch granules or granule–granule contacts to form the close packing of the vitreous endosperm. Therefore transition from vitreous to floury endosperm is at least the result of both protein and starch gradients. These gradients are probably associated with metabolic gradients that have been observed during endosperm development.     

In vitro pullulanase activity of wheat (Triticum aestivum L.) limit-dextrinase type starch debranching enzyme is modulated by redox conditions

Expression of a limit-dextrinase (LD) type starch debranching enzyme (EC 3.2.1.41) was observed in developing wheat (Triticum aestivum L.) endosperm and germinating grains, indicating a role for the enzyme in both biosynthesis and degradation of starch. A full-length cDNA, TaLD1, encoding LD in wheat developing kernels was isolated and predicted to encode a 98.6 kDa mature protein active in amyloplasts. Isolated cDNA was expressed in Escherichia coli to produce a recombinant His-tagged LD, which mainly accumulated in inclusion bodies as an inactive enzyme. Extraction of His-tagged LD from the inclusion bodies followed by dialysis under thiol/disulphide redox conditions allowed partial refolding of the protein and detection of pullulanase specific activities by zymogram analysis and enzyme assays. Several active conformations were demonstrated by the recombinant TaLD1 and pullulanase activity could be modulated by redox conditions in vitro. The results suggest that cellular redox conditions may regulate the level of LD activity in wheat tissues.     

Ultrastructure of Consecutively Extracted and Flocculated Gliadins and Glutenins

Gliadin and glutenin are characterized by specific ultrastructures, which depend on variety and separation conditions. Gliadins, extracted with 80% ethanol, of Israeli spring wheat ‘Ariel’ appeared as spherical bodies within an amorphous perforated matrix. The gliadins of a commercial sample of U.S. hard red winter wheat were deposited in bundles of bodies of concentric membrane-like units during water dialysis and they tended to separate while heating at 120 °C. Acetic-acid-extracted glutenins heated at 120 °C appeared as amorphous compact agglomerated particles beside dispersed aggregates, fibril-like patterns and oil-like bodies. The extracted glutenins, which were dialysed vs water, appeared as dispersed or aggregated particles beside oil-like bodies embedded in and/or encapsulated by coagulated protein. Differences were found in high-performance capillary electrophoresis patterns of both gliadins and glutenins between the Israeli spring wheat ‘Ariel’ and the good baking quality U.S. hard red winter wheat ‘Karl 92’; indicating that the structural differences are a result of different proteins and differences in the physicochemical properties of the proteins.     

栽培大豆Rubisco小亚基基因（rbcS）全长cDNA的克隆及原核表达

根据NCBI中发表的大豆Rubisco小亚基基因（rbcS）序列（AF303939-1）设计特异引物,以吉农13大豆为实验材料,采用Trizol法提取叶片总RNA,通过RT-PCR克隆大豆rbcS的cDNA。将该基因与原核表达载体pET-30a（+）连接,转化大肠杆菌E.coli BL21感受态细胞,双酶切鉴定后筛选阳性克隆,测序结果显示：rbcS全长 696bp,其中开放阅读框为537bp,编码178个氨基酸;选择含大豆rbcS cDNA阳性克隆菌液IPTG诱导,经SDS-PAGE分析,诱导表达出分子量为29.1kDa的融合蛋白,表达产物大小与预计理论值相符。诱导7h蛋白表达量最高,为64.15%。     

甜菜无融合生殖系AFLP指纹图谱试验体系的建立

通过利用单酶切和单接头连接体系,在T4连接酶作用下进行连接,以连接产物为模板,在选择引物和ExTaq聚合酶作用下进行PCR特异扩增,扩增产物用琼脂糖凝胶检测分析。通过对甜菜叶片基因组DNA的分析,确立了适合于甜菜无融合生殖系的最适宜的AFLP试验体系。该方法操作简单、费用低,有利于该项技术的推广和应用。     

An expression of an insect membrane-bound cytochrome P450 CYP6AA3 in the Escherichia coli in relation to insecticide resistance in a malarial vector

This laboratory investigation was carried out at the Faculty of Sciences, Mahidol University, Thailand during October 2007 to May 2009. The objectives of this study include: the search for heterologous expression of the cytochrome P450 CYP6AA3 enzyme of the Anopheles minimus mosquitoes in relation to Malaria disease and to provide some information on molecular mechanism of insects' pyrethroid resistance. The polymerase chain reaction aided by the Pfu DNA polymerase and some specific generated primers were used to modify the CYP6AA3 gene. The PCR product was ligated with a predigested pET-3a at the NdeI and BamHI restriction sites. The modified CYP6AA3 enzyme was expressed in the Escherichia coli BL21 (DE3) pLysS in order to achieve a high amount of soluble form of its expression. The results showed that the use of the isopropyl-beta-D-thiogalactopyranoside (IPTG) and incubation together with ferric chloride and delta-aminolevulinic acid did not increase any soluble form of the CYP6AA3 enzyme. A significant amount of soluble enzyme was produced upon the replacement of the 30 N-terminal residues with a short peptide where it gave Ldelta30CYP6AA3 protein and after purification process was taken place, it yielded up to 10.64 mg 10 L(-1) or approximately 1 mg L(-1) of the homogenous Ldelta30CYP6AA3. When this purified Ldelta30CYP6AA3 protein was used in a metabolizing process with the cypermethrin, deltamethrin and permethrin substrates, it gave their apparent Km values for cypermethrin and deltamethrin of 12.5 and 23.5 microM, respectively. The heterologous expression carried out with the use of the E. coli gave a high amount of soluble CYP6AA3 enzyme of the An. minimus mosquitoes hence the modified technique being used was successfully achieved.     

Ultrastructure of potato tubers infected with potato virus X

The ultrastructure of Katahdin tubers infected with potato virus X (PVX) is compared with PVX-free tubers by electron microscopy. Electron-dense globules surrounding the inner periphery of the tonoplast were observed in PVX-infected tubers, while PVX-free tubers did not show such bodies. Other organelles were comparable in PVX-infected and PVX-free tubers     

Biochemical characterization of QTLs associated with endosperm modification in quality protein maize

Genetic analysis using quality protein maize (QPM) recombinant inbred lines derived from K0326Y QPM and W64Ao2 identified three quantitative trait loci (QTL) in bins 1.06, 7.02 and 9.03 associated with opaque2 endosperm modification. We evaluated the effects of these QTLs on protein accumulation and starch physicochemical properties. The QTL in bin 1.06 is close to α-zein genes, and vitreous individuals with this QTL had increased accumulation of 19-kDa α-zein, 27-kDa γ-zein and legumin-1. The QTL in bin 7.02 corresponds to the γ-zein locus, and greater accumulation of this protein was found in vitreous individuals. The QTL in bin 9.03 is close to starch biosynthetic genes; greater accumulation of granule-bound starch synthase and amylose was observed in vitreous kernel samples with this locus and that in bin 1.06, as well as less gelatinization enthalpy and crystallinity. Vitreous kernels contained angular-shaped/compact starch granules and more short-intermediate length chains of amylopectin. These results support that endosperm modification in QPM is associated with increased accumulation of γ-zein and other storage proteins, but also show that synthesis of less crystalline starch with more amorphous regions at the periphery of granules, which favor their packing and association with endosperm proteins, may also be an important factor.