Bowman-birk proteinase inhibitor confers heavy metal and multiple drug tolerance in yeast

Cultured Coptis japonica cells show tolerance to various toxic compounds. By yeast functional screening of cadmium (Cd) plates with its cDNA library, we isolated a gene encoding Bowman-Birk proteinase inhibitor (CjBBI). The yeast transformant of CjBBI showed multiple tolerance to various drugs adding to Cd, and revealed reduced Cd accumulation in cells. Preferential organs for Cjbbi expression were aerial parts of intact plants, and the subcellular localization of CjBBI was shown, using its green fluorescent protein fusion, to be the apoplast. Induction of Cjbbi expression by Cd treatment suggested that CjBBI was responsible for the tolerance to Cd observed in C. japonica cells.     

Giemsa-C带揭示的绵枣儿多倍体复合体染色体变异

绵枣儿是分布在东亚的多倍体复合体。以Giemsa-C带法对分布在中国的绵枣儿24个居群进行了染色体变异分析。AA和BB细胞型大部分居群未发现变异,分别具a2和b1染色体的近着丝点着丝粒带。AABB虽无居群内变异,但居群间有所不同。其中柳林、商南和徐州居群带型相同,带纹丰富。元宝山居群只有b1的近着丝粒带,而灵岩山居群具a2和b1的近着丝粒带。根据已有的研究资料推测,绵枣儿b1和a2上的近着丝粒带显示的应当是高度重复的rRNA基因;大庆和文县居群一个体该位点的杂合可能是由于部分rRNA拷贝的同源染色体间转移;AABB起源后随时间推移会发生rRNA重复位点的丢失;柳林等居群丰富的带纹可能是其刚刚起源时重复基因关闭的表征,随时间推移同样可能会丢失。另外大量的实验证据表明,BB比AA细胞型可能更易于发生染色体结构变异。     

草食动物对结缕草种子散布及发芽力的影响

研究了草食动物(牛、山羊)对辽东半岛结缕草种子散布及发芽力的影响。结果表明:风干牛粪、羊粪中结缕草种子的数量分别为101.7和6.88粒.g-1;牛、羊的采食和消化对结缕草种子的生活力没有影响,但提高了其发芽率(分别为74.12%和67.77%)、发芽势(分别为24.34%和17.72%)及活力指数(分别为41.86和37.38),缩短了其发芽时间(分别为12.53和12.70d);牛粪和羊粪中结缕草种子的发芽率虽有提高但没有达到其生活力水平;牛对结缕草种子散布及发芽力的影响效果均好于山羊。     

Enhanced tolerance against freezing stress in<Emphasis Type="Italic">Escherichia coli</Emphasis> cells expressing an algal cyclophilin gene

Members of the cyclophilin (Cyp) family are known to function as co-chaperones, interacting with chaperones such as heat shock protein 90, and perform important roles in protein folding under high temperature stress. In addition, they have been isolated from a wide range of organisms. However, there have been no reports on the functions of algal Cyps under other stress conditions. To study the functions of the cDNAGjCyp-1 isolated from the red alga (Griffithsia japonica), a recombinant GjCyp-1 containing a hexahistidine tag at the amino-terminus was constructed and expressed inEscherichia coli. Most of the gene product expressed inE. coli was organized as aggregate insoluble particles known as inclusion bodies. Thus, the optimal time, temperature, and concentration ofl(+)-arabinose for expressing the soluble and nonaggregated form of GjCyp-1 inE. coli were examined. The results indicate that the induction of Cyp, at 0.2%l(+)-arabinose for 2 h at 25°C, had a marked effect on the yield of the soluble and active form of the co-chaperone as PPlase. An expressed fusion protein, H₆GjCyp-1, maintained the stability ofE. coli proteins up to-75°C. In a functional bioassay of the recombinant H₆GjCyp-1, the viability ofE. coli cells overexpressing H₆GjCyp-1 was compared to that of cells not expressing H₆GjCyp-1 at −75°C. For all the cycles of a freeze/thaw treatment, a significant increase in viability was observed in theE. coli cells overexpressing H₆GjCyp-1. The results of the GjCyp-1 bioassays, as well asin vitro studies, strongly suggest that the algal Cyp confers freeze tolerance toE. coli.     

龟纹瓢虫卵黄蛋白的分子特性及发生动态

研究了龟纹瓢虫Propylea japonica (Thunberg) 卵黄蛋白的基本特性以及卵黄发生过程中卵黄蛋白的动态变化。PAGE和SDS-PAGE实验表明,龟纹瓢虫卵黄蛋白分子量为294.81±40.70 kD,并由分子量分别为144.68±0.03 kD和51.23±0.27 kD的两种亚基组成。对卵黄蛋白的氨基酸组成和含量分析发现,其必需氨基酸总量占57.48％,略高于非必需氨基酸,其中谷氨酸（Glu）含量最高,为15.26％;色氨酸（Trp）和蛋氨酸（Met）含量较低,分别为0.50％和0.11％。采用间接竞争ELISA法,系统测定了龟纹瓢虫成虫期脂肪体、血淋巴和卵巢中卵黄蛋白的动态变化,结果表明：脂肪体是卵黄原蛋白合成的场所,卵黄原蛋白的合成始于羽化后第2天;脂肪体、血淋巴和卵巢中卵黄原蛋白的滴度在羽化后第4天开始迅速上升,至成虫期的第8天左右达到高峰期。     

狗脊孢壁发育超微结构的研究

鳞毛蕨型孢子类型众多,初步研究表明形态相似的孢子类型其孢壁发育特征存在差异,因此有必要对各代表类群的孢壁发育进行深入地研究。该文利用透射电镜对乌毛蕨科(Blechnaceae)狗脊(Woodwardia japonica)孢壁结构和发育的超微结构进行研究。结果表明:(1)狗脊孢子囊的结构由外向内分别为孢子囊壁细胞、两层绒毡层细胞和孢子母细胞;(2)狗脊孢子具乌毛蕨型(Blechnoid type)外壁,表面光滑,由两层构成,裂缝区域具辐射状的槽;(3)周壁属于空心型(cavity type),由四层构成,从内向外分别为P1、P2、P3和P4层,前三层叠合在一起,层间有不同程度的空隙,P4层与前三层之间具有明显而连续的空腔,并隆起形成片状褶皱纹饰;(4)有小球体和小杆共同参与孢子周壁的形成,周壁部分或全部来源于孢子囊壁细胞。综上所述,狗脊孢子与同属于鳞毛蕨型的贯众(Cyrtomium fortunei)和朝鲜介蕨(Dryoathyrium coreanum)孢壁的发育在周壁结构、周壁各层的发育顺序、周壁来源和参与成壁的特征物质等方面存在差异。该研究有利于进一步理解蕨类植物孢壁所蕴含的分类和演化上的科学意义和价值。     

龟纹瓢虫四虫态肠道细菌分离及鉴定

目的通过对龟纹瓢虫四个虫态肠道菌群研究,探讨其营养生理,为改良龟纹瓢虫人工饲料,大量扩繁天敌昆虫奠定基础。方法按照传统的分离方法从龟纹瓢虫瓢卵、幼虫、蛹及雌成虫或肠道内分离15个不同菌株,对其染色反应、培养性状,菌体形态和生理生化性状进行系统研究。结果从龟纹瓢虫卵内分离鉴定出短芽胞杆菌（Bacillus brevis）、球性芽胞杆菌（Bacillus sphaericus）、棍状杆菌属（Clavibacter）和一种未知分类地位的菌;幼虫肠道内分离鉴定柠檬酸杆菌属（Citrob acter）、短状杆菌属（Brachybacterium）、微杆菌属（Microbacterium）、皮杆菌属（Dermabacter）、浸麻芽胞杆菌属（Bacillus macerans）、纤维单胞菌属（Cellulomonas）;蛹肠道分离鉴定出短芽胞杆菌（Bacillus brevis）、蜡状芽胞杆菌（Bacillus cereus）、微杆菌属（Microbacterium）、不动杆菌属（Acinetobacter）;成虫肠道分离鉴定出短芽胞杆菌（Bacillus brevis）、球性芽胞杆菌（Bacillus sphaericus）、柠檬酸杆菌属（Citrob acter）、不动杆菌属（Acinetobacter）、地衣芽胞杆菌（Bacillus licheniformis）、凝结芽胞杆菌（Bacillus coagulans）和巨大芽胞杆菌（Bacillusmegaterium）。结论不同虫态龟纹瓢虫肠道中细菌种类不同,为进一步研究适合龟纹瓢虫不同时期生长和繁殖的人工饲料的配比提供了依据。     

地中海地区稻种资源的籼粳分类及遗传多样性

利用SSR标记及程氏综合指数法分析了109份从地中海引进的水稻种质资源的遗传多样性和籼粳类型,同时利用籼粳测交法分析了其中37份资源的籼粳亲和性.结果表明,大部分引进的水稻种质属粳稻类型,基于SSR聚类、程氏综合指数法分析所确定的粳型品种数分别占引进种质的80.73%和77.98%,基于籼粳亲和性分类所确定的粳型品种数占供试37份资源的75.68%.地中海稻种资源具有较高的遗传多样性,平均有效等位基因数为3.84个,Nei多样性指数平均值为0.482,其中籼稻群与粳稻群的Nei多样性指数分别为0.459和0.340,籼稻遗传多样性高于粳稻.研究结果对于科学引进、合理保存和有效利用国外水稻种质改良国内水稻品种具有指导意义.