蜡梅金属硫蛋白基因的克隆与原核表达

金属硫蛋白(metallothionein,MT)是一类富含Cys,能够结合重金属的低分子量蛋白质,广泛分布于生物界。在构建好的蜡梅花cDNA文库并进行EST分析的基础上,通过随机克隆测序得到了1个蜡梅金属硫蛋白的cDNA,命名为CpMetallothionein(CpMT)。CpMTcDNA全长为1083bp,基因内部含有一长度为240bp的开放阅读框,可编码79个氨基酸残基。将CpMT插入原核表达载体pET-32a,并转化Origami2感受态细胞。诱导表达产物经SDS-PAGE结果显示,目的蛋白约为30kD。表达的融合蛋白以包涵体和可溶性蛋白2种形式存在,用His-Bind蛋白纯化回收试剂盒对其进行纯化回收,得到了高纯度蛋白,为今后研究奠定基础。     

浙江凤阳山－百山祖自然保护区综合考察报告

１９８０年以来，对浙江凤阳山－百山祖自然保护区先后３次考察，揭示了这一自然保护区生物资源一些特点，即生物群落地带的特殊性、生物区系成分的古老性、生物物种的多样性、珍稀动植物种类的丰富、森林植被垂直分布系列的完整，本区又是一些植物的分化和变异中心，是一处十分难得的森林生态和生物多样性自然保护区，同时又介绍了保护区建立前后所开展的一些科研活动。     

菜青虫[Artogeia rapae(L.)]抗药性研究 Ⅲ、混配制剂的增效作用

在室内测定了溴氰菊酯(deltamethrin)、氯氰菊酯(cyperme-thrin)、氰戊菊酯(fenvalerate)、北京菊酯Ⅱ与辛硫磷以不同比例混配对菜青虫的增效作用。溴氰菊酯与辛硫磷以1:20和1:100的比例混配,共毒系数分别达到427和491。氯氰菊酯与辛硫磷以1:20的比例混配,共毒系数为165,北京菊酯Ⅱ与辛硫磷混配(1:5),共毒系数达到558。部分组合进行了田间药效试验,获得良好增效效果。     

Total Polyphenols,Antioxidant and Antiproliferative Activities of Different Extracts in Mungbean Seeds and Sprouts

The aim of this investigation was to evaluate the biological, alcohol dehydrogenase (ADH) and antiproliferative activities of different extracts of mungbean seeds and sprouts. All extracts from the sprouts showed higher contents of total phenolics (TP), total flavonoids (TF), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than from seeds. The highest DPPH and tyrosinase inhibition activities were registered in ethyl acetate (EtOAc) extract. ADH activity of methanol (MeOH), n-hexane (n-hexane) and n-butanol (n-BuOH) extracts from sprouts was significantly higher (P < 0.05) than from seeds. However, the highest ADH activity was found in water extract of seeds. According to 3-(4, 5-dimethylthiazol -2-yl)-2, 5-diphenyltetrazolium bromide) (MTT) assay, extracts from sprouts were more effective against Calu-6 (human pulmonary carcinoma) and SNU-601 (human gastric carcinoma) cells than from seeds. EtOAc extract showed the highest antiproliferative activity in both sprouts and seeds, followed by n-hexane extraction. During sprouting of mungbean, all the studied components significantly increased. In conclusion, the extracts of sprouts are more effective than from seeds and could be a potential source of antioxidants linked with health benefits.     

小豆杂交后代主要农艺性状的遗传参数分析

本文用京农2号×S5033。杂交后代F3～F5世代的材料,以家系为样本研究了主要农艺性状的遗传参数变化规律．结果表明：1）生育前期、全生育期、主茎节数、单荚粒数和单株产量5个性状的F。家系次数分布呈正态,而株高、单株荚数2个性状的F。家系次数分布呈明显的偏低亲连续性偏态分布,均属数量性状遗传;2）对F3家系进行选择时,株高和单株荚数的遗传潜力最大,其次为单株产量,而对单荚粒数选择遗传进展将很小：对民代群体来说,单株产量的GCV、RGS远大于其它性状,说明进行单株选择时把单株产量放到相当重要的位置对高产育种是有益的．3）高世代按一定方向对某性状进行选择后,其该性状的平均值有所提高,但后代的遗传潜力都很小,不宜再作直接选择,选用其它性状进行间接选择将会提高选择效果;而高世代通过主要农艺性状的综合选择其后代仍具有较高的选择潜力．     

Factors influencing carbon decomposition of topsoils from the Brazilian Amazon Basin

 The influence of texture and local climate, especially precipitation, on C decomposition was evaluated in topsoils under forest and pastures at different sites located in the western, central, and eastern Brazilian Amazon Basin. Independent of the geographical location and vegetation cover, C decomposition was lower in topsoils of fine texture with a sand/clay ratio of less than 1, compared to topsoils of coarse a texture with a sand/clay ratio ranging from 2 to 8. In the former, the low sand/clay ratio appears to reduce C decomposition. In the latter, besides the effect of the high sand/clay ratio, the local climate, especially the annual precipitation, seems to play an important role in controlling C decomposition. Received: 2 March 1998     

Antiproliferative Activity of Korean Wild Vegetables on Different Human Tumor Cell Lines

This study was conducted to determine the antiproliferative activity of 24 Korean wild vegetables. The methanol extracts of these wild vegetables were used against lung, breast, colon and gastric cancer cells, and the results were assessed by MTT assay. It was found that at the extract concentration of 400 mgL⁻¹ 14 plants exercised antiproliferative activity over 80% against the lung cancer cells, one plant among six—against breast cancer cells, and two plants among six—against colon cancer cells, respectively. Eighteen wild vegetables had the hyperplasia inhibition activity against gastric cancer cells over 23.6% at all extract concentrations, however, only six plants had the antiproliferative activity over 80% in 600 mgL⁻¹. It was found that the extracts from Youngia sonchifolia, Synurus deltoides, Syneilesis palmata, and Cephalonoplos segetum, in concentration of 400 mgL⁻¹ inhibited the hyperplasia of lung cancer cells over 95% and Angelica gigas—both lung and colon cancer cells over 95%. In conclusion, the studied wild vegetables’ methanol extracts possess dose dependent antiproliferative properties, based on their bioactive compounds, mainly polyphenols, but some of them as Hypericum ascyron against lung cancer are not effective and even course harm.     

Difference in Allelopathic Potential as Influenced by Root Periderm Colour of Sweet Potato (Ipomoea batatas)

Laboratory bioassay and high‐performance liquid chromatography (HPLC) analysis were conducted to determine the allelopathic potentials of aqueous or methanol extracts from three different coloured sweet potato [Ipomoea batatas L. (Lam)] cultivars by plant part. The aqueous extracts applied on filter paper significantly inhibited root growth of alfalfa (Medicago sativa L.). Aqueous leaf leachates at 40 g dry tissue l^?1 (g l^?1) from white sweet potato cultivar ‘Sinyulmi’ showed the highest inhibition against alfalfa, followed by yellow ‘Sinhwangmi’ and purple ‘Jami’. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. Aqueous and methanol extracts from leaves showed the most inhibitory effect on alfalfa root growth followed by stems and roots. By means of HPLC analysis, leaf samples of sweet potato had the highest amount of phenolic compounds followed by stems and roots. Total content of these compounds was highest for leaf extracts (37.7 mg 100 g^?1), detected in EtOAc fraction, especially trans‐cinnamic acid (20.9 mg 100 g^?1). These results suggest that sweet potato plants are allelopathic and that their activities differ depending on plant part as well as root periderm colour.     

Herbicidal Potential and Quantification of Suspected Allelochemicals from Four Grass Crop Extracts

Unknown compounds in crop plants are inhibitory to seed germination and early seedling growth of weed plants. A Petri dish assay showed that barley (Hordeum vulgare L.), oats (Avena sativa L.), rice (Oryza sativa L.) and wheat (Triticum aestivum L.) extracts significantly reduced root growth of alfalfa (Medicago sativa L.), barnyard grass (Echinochloa crus‐galli, Beauv. var. oryzicola Ohwi.) and eclipta (Eclipta prostrata L.). As the concentration of crop extracts increased, root growth of the test plants were significantly reduced. A high‐performance liquid chromatography analysis with nine standard phenolic compounds showed that the concentrations and compositions of allelopathic compounds depend on the extracted plant extracts. Caffeic acid, hydro‐cinnamic acid, ferulic acid, m‐coumaric acid, p‐coumaric acid and coumarin were present in all the crop plant species, and hydro‐cinnamic acid were detected as the highest amount. Coumarin at 10^?3 m significantly inhibited root growth of alfalfa and barnyard grass more than that of eclipta. The research suggests that extracts of barley, oats, rice and wheat have an allelopathic effect on alfalfa, barnyard grass and eclipta and that the findings of bioassay were considerably correlated with the type and amount of causative allelochemicals, indicating that the allelopathic effects on three test plants were ranked in order of wheat (highest), barley, rice and oats (lowest). The results may have value in enabling weed control based on natural plant extracts or crop residues in the fields.     

Wnt5a expression in canine osteosarcoma

Osteosarcoma is the most common primary malignancy of bone in dogs and is associated with poor long‐term outcomes due to its highly metastatic nature. A better understanding of the signalling pathways and proteins involved with osteosarcoma pathogenesis may aid in improved outcomes through the use of targeted therapies. The Wnt5a protein, a ligand for the non‐canonical Wnt signalling pathway, is implicated in mediating the aggressiveness of cancer cell lines, including those of human osteosarcoma origin. Given the close relationship between human and canine osteosarcoma, the primary goal of this study was to characterize Wnt5a expression in canine osteosarcoma. Second, if Wnt5a expression was present in canine osteosarcoma, the study aimed to determine any potential association with clinical outcome and clinical variables in similarly treated osteosarcoma‐bearing dogs. Wnt5a expression was present in 26 of the 48 (54%) cases of canine osteosarcoma. Wnt5a expression was not associated with progression‐free survival (P = 0.4) or overall survival (P = 0.1).