一种基于Xcm Ⅰ酶切的pUC19-T载体的构建（摘要）

[目的]构建以pUC19质粒为基础可利用XcmⅠ内切酶制备的T载体。[方法]化学合成2条含有双XcmI酶切位点的互补寡聚核苷酸链,经过变性、复性后克隆入pUC19质粒的HindⅢ和BamHⅠ位点之间,通过XcmI酶切后得到一个线性化的带有3末端突出一个T碱基的T载体。[结果]经TA克隆验证,制备的pUC19-HB-T载体对PCR产物的克隆率达到95%以上。[结论]所构建的pUC19-HB-T载体可用于PCR产物的克隆、测序及后续分子生物学操作。     

三十烷醇(TA)纳米制剂的制备及对绿豆种苗生长的影响

三十烷醇作为一种新型植物调节剂,目前在我国有着广泛的应用和研究。对三十烷醇（TA）采用纳米技术方法处理,制备三十烷醇纳米制剂,并初步研究了该制剂对绿豆种苗生长的影响。通过比较得出以下结论：通过超声波振荡法制备三十烷醇的纳米制剂,三十烷醇颗粒粒径可达到50~200nm。在三十烷醇（TA）使用浓度范围为0~2mg/L的条件下,三十烷醇（TA）纳米制剂浓度为0.5mg/L时绿豆种苗长势最好。     

Physico-chemical properties and antioxidant capacity of different jujube (Ziziphus jujuba Mill.) cultivars grown in loess plateau of China

The physico-chemical properties and antioxidant capacity of the five main jujube varieties: Junzao, Lingbaozao, Jinzao, Zanhuangzao and Lizao collected from loess plateau of China were determined. The analyzed components included fruit yield, moisture content, total mass per fruit, pH, titratable acidity (TA), reducing sugars, total sugars, total soluble solids (TSS), ascorbic acid, total phenolics content, total flavonoids content and several pure phenolic compounds. The output of the analyses showed higher amounts of ascorbic acid and phenolics in these jujube varieties than in some common fruits. The antioxidative capacity of the jujube extracts, evaluated with the reducing power, the β-carotene bleaching, the 2,2-diphenyl-1-picrylhydracyl (DPPH•), and the 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonicacid) (ABTS•⁺) scavenging methods, showed that the antioxidant activity of the extracts of Lingbaozao was excellent for free radical scavenging and a potent natural antioxidant of commercial value. Statistically significant differences were observed between jujube cultivars investigated with regards to the measured parameters except rutin content of fruit. These results demonstrated that the cultivar was the main factor which influences the physico-chemical properties and antioxidant activity of jujubes.     

柔嫩艾美耳球虫BJ株TA4基因的表达及电泳分析

 球虫子孢子表面抗原TA4(25kD)是通过二硫键连接8和17kD 2条多肤形成的,在孢子化后期合成。E.tenella BJ株的TA4基因同国外株的同源性为99％。本试验进行了TA4基因的原核融合表达,并对表达蛋白的SDS-PAGE电泳特性进行探究。试验发现,以pGEX-KG为载体,用IPTG可诱导TA4基因在E.coli BL21(DE3)中的表达。SDS-PAGE表明,融合蛋白大小约43 kD,而非推测的51 kD,诱导6 h的蛋白表达量即可达到较高水平,表达量约为31％。采用抗GST抗体进行Weste     

Untersuchungen über flüchtige Aromastoffe der Kartoffel. I. Isolation und Anreicherung flüchtiger Aromastoffe mit der Dynamischen Headspace Technik

Zusammenfassung Aromastoffe sind als wertgebende Inhaltsstoffe wesentlicher Bestandteil der Qualit?t pflanzlicher Lebensmittel. Sie liegen als komplexe Vielstoffgemische in unserer Nahrung vor und sind nur schwer analytisch fa?bar. Den Verfahren zur Abtrennung und Anreicherung von Aromastoffen kommt daher eine besondere Bedeutung zu. Mit der ‘Dynamischen Headspace Technik’ lassen sich die flüchtigen Stoffe des nativen Kartoffelaromas unter schonenden Bedingungen isolieren. Das Aromaspektrum der rohen Kartoffel setzt sich vorwiegend aus unges?ttigten Aldehyden, Alkoholen und einem Furanderivat zusammen. Für die isolierten Verbindungen lassen sich Variationskoeffizienten zwischen 3 und 20% ermitteln. Hinsichtlich des sensorischen Eindruckes zeigen die Aromakonzentrate ein typisches Kartoffelaroma.     

Characterization of transgenic male sterility in alfalfa

Dependable male sterility would help to make hybrid cultivar development a reality in alfalfa once higher levels of heterosis are attained. Alfalfa plants obtained by genetic transformation with a construct containing the Barnase gene under the control of a tobacco anther tapetum specific promoter were studied. Vacuolization and degeneration of the tapetal cell cytoplasm at a premeiotic stage of development were observed in all five transformed plants (T₀)examined, but the severity of the abnormalities varied greatly among pollen sacs of a genotype. During the meiotic stage, some pollen sacs showed reduction in size, and the tapetum generally appeared thinner when compared to those of the non transgenic plants; tapetal cells showed abnormal vacuolization and signs of cytoplasm degeneration. Despite this, some microspores were formed and some pollen grains were shed in all the T₀ plants, but these were highly variable in size and had very low in vitro germinability. Self-fertility was negligible. The T₀ plants were crossed with one or two unrelated non transgenic male-fertile plants. Mendelian segregation was observed with two exceptions. Instability of the trait in F₁ progenies was noticed, varying for different T₀ parents. F₁ plants exhibiting higher sterility than the primary transformants were observed, indicating that it should be possible to obtain good male sterile plants by backcrossing this trait into different genetic backgrounds. The possible use of this transgenic male sterility in alfalfa breeding is briefly discussed. This revised version was published online in July 2006 with corrections to the Cover Date.