Cloning and Expression of Small cDNA Fragment Encoding Strong Antiviral Peptide from <Emphasis Type="Italic">Celosia cristata</Emphasis> in <Emphasis Type="Italic">Escherichia coli</Emphasis>

A small cDNA fragment containing a ribosome-inactivating site was isolated from the leaf cDNA population of Celosia cristata by polymerase chain reaction (PCR). PCR was conducted linearly using a degenerate primer designed from the partially conserved peptide of ribosome-inactivating/antiviral proteins. Sequence analysis showed that it is 150 bp in length. The cDNA fragment was then cloned in a bacterial expression vector and expressed in Escherichia coli as a ~57 kD fused protein, and its presence was further confirmed by Western blot analysis. The recombinant protein was purified by affinity chromatography. The purified product showed strong antiviral activity towards tobacco mosaic virus on host plant leaves, Nicotiana glutinosa, indicating the presence of a putative antiviral determinant in the isolated cDNA product. It is speculated that antiviral site is at, or is separate but very close to, the ribosome-inactivating site. We nominate this short cDNA fragment reported here as a good candidate to investigate further the location of the antiviral determinants. The isolated cDNA sequence was submitted to EMBL databases under accession number of AJ535714.     

银鲴自然群体线粒体DNA的遗传分化

运用２１种限制性内切酶对银鲴自然群体进行了ｍｔＤＮＡ的限制性片断长度多态性（ＲＦＬＰ）分析。发现银鲴自然群体存在丰富的ｍｔＤＮＡ多态性,从４个群体３９个个体中,共检测到１２种单倍型,对这一现象的成成因进行了探讨。依据单倍型和群体的系统发育关系,结合地理分布的资料,对其现今分布区相互间的历史联系及其对银鲴起源和分化的影响进行了分析。     

若干因子对鸡冠花悬浮培养中花色素苷积累的影响

本文研究几种植物生长调节剂和蔗糖浓度对鸡冠花细胞悬浮培养中花色素苷积累的影响。结果表明,细胞分裂素KT使花色素苷积累明显高于6-BA,且KT在2 μmol/L时积累量最高;2,4-D在2 μmol/L时对花色素苷积累效果明显,其它浓度的2,4-D和NAA对花色素苷积累效果不明显。高浓度蔗糖有利于花色素苷积累;MS+2,4-D(2 μmol/L)+KT(2 μmol/L)+蔗糖(292 mmol/L)为鸡冠花悬浮细胞培养生产花色素苷的最佳培养基。研究中还发现,在黑暗条件培养下无花色素苷积累,推断光是诱导花色素苷积累的主要因素。随着继代次数的增加,花色素苷含量明显增高,但到第4代时基本稳定。     

入侵植物青葙叶片提取物对红脉穗螟体重及蛹发育的影响

【背景】青葙是我国的传统中草药,有关其次生物质对植物病害的活性已有报道,但其在害虫防控方面的研究还较少。【方法】为明确青葙体内次生物质对害虫的生物活性,研究了青葙叶片4种溶剂提取物对红脉穗螟幼虫体重及蛹发育的影响。【结果】除石油醚提取物外,其余3种溶剂(甲醇、正丁醇、去离子水)提取物均会对红脉穗螟体重和成虫羽化造成影响,其中,甲醇提取物影响最大;各提取物中,仅甲醇提取物对虫体蛹发育造成影响,对蛹重的抑制率达到39.35%,对蛹长的抑制率达到29.05%。【结论与意义】青葙植株体内存在对昆虫生长发育起调控作用的次生物质。     

木荷属(山茶科)一新变种——扁果银木荷

报道了四川德昌县发现的山茶科(Theaceae)木荷属(Schima Reinw.)一新变种--扁果银木荷(Schima argentea Pritz.var.platycarpa Q.Luo).新变种花瓣长2～2.6 cm,宽1.6～2.2cm,内面基部被柔毛,蒴果扁球形,直径1.7～2.1cm,高1～1.3cm等特...     

Dwelling at the oxycline: does increased stratification provide a predation refugium for the Lake Victoria sardine Rastrineobola argentea?

1. We tested the hypothesis that increased hypoxia in Lake Victoria provides a refugium for the cyprinid dagaa ( Rastrineobola argentea ) against hypoxia-sensitive Nile perch ( Lates niloticus ).
2. Hypoxia in the main habitat of dagaa was rare during 1979–80, but lasted 3–5 months in 1987 and 1988, during which time adult dagaa spent the day just above the oxycline instead of near the bottom.
3. Dissolved oxygen concentrations in the layer just above the oxycline were not critical for Nile perch, but a mass kill of this species following a sudden upwelling of hypoxic water suggested that oxycline-dwelling is risky.
4. Our data suggest no difference between dagaa and Nile perch in the level at which dissolved oxygen starts to limit their vertical distribution in the water column, but dagaa seems to be even more sensitive to extreme hypoxia (<1–2 mg O2 L−1) than Nile perch.
5. We argue that oxycline-dwelling dagaa are not seeking a predation refugium but that they are limited by low oxygen levels in reaching their feeding areas near the bottom.     

高空气球搭载实验对普通鸡冠花抗氧化作用的诱变效应

利用高空气球搭载黄色普通鸡冠花(CelosiaargenteaL.)(yellowflower)种子,进行空间诱变处理。飞行高度为40.112km,飞行时间近4h,回收后播种栽培,采收子一代(SP1)的花序和叶片。采用比色法研究搭载组和对照组花序、叶片水提液对超氧阴离子自由基(O2-.)和羟自由基(·OH)的清除作用,并测定分析了样品的VC,黄酮醇的含量和SOD活力。结果表明,搭载组和对照组花序和叶片水提液均能降低·OH引发的还原型细胞色素C[Cyt·C(Ⅱ)]氧化作用和O2-.对羟胺的氧化作用,而搭载组样品水提取液清除活性氧的能力均比对照组显著提高,这与其自由基清除剂含量和活力的增高有关。这说明高空环境诱变处理对鸡冠花中抗氧化活性物质的合成和抗氧化功能产生了显著效应。     

鸡冠花叶蛋白质营养价值的评价研究

应用模糊识别法和氨基酸比值系数法,分别以鸡蛋蛋白南为标准蛋白,以ＷＨＯ／ＦＡＯ氨基酸参考模式为评价标准,对３种鸡冠花叶蛋白质营养价值进行了全面评价,并与１０种常见叶菜蛋白进行对照比较。结果表明,３种鸡冠花叶（干品）蛋白质含量为２３．７％￣２７．４％,蛋白质中氨基酸种类齐全,其含量为８３．４７％￣８６．９４％,必需氨基酸（ＥＡＡ）占总氨基酸量的４０．２％￣４１．７％,第一限制性氨基酸为含硫氨基酸（Ｍ     

青葙子化学成分初步研究

本文报道青葙子的主要化学成分。经测定,青葙子氨基酸种类比较齐全,必需氨基酸含量较高,占总氨基酸含量的42.85%。种子含有丰富的脂肪油,主要成分为:棕榈酸(18.225%)、硬脂酸(2.459%)、油酸(27.995%)、亚油酸(44.522%)和亚麻酸(2.374%)等,不饱和脂肪酸的含量达79.276%。种子还含有种类较齐全的矿质元素,具有较高的营养价值。     

长形肉豆蔻Myristica argentea Warb.化学成分研究(英文)

从长形肉豆蔻Myristica argentea乙醇提取物乙酸乙酯部分分离得到12个化合物,经理化和波谱分析分别鉴定为黄樟醚(1)、甲基丁香酚(2)、异甲基丁香酚(3)、3′-羟基异黄樟醚(4)、7-羟基-3′,4′-亚甲二氧基黄烷(5)、1,4-苯二甲酸二甲酯(6)、内消旋-二氢愈创木脂酸(7)、赤式-1-(4-羟基-3-甲氧基苯基)-4-(3,4-亚甲二氧基苯基)-2,3-二甲基丁烷(8)、赤式-1-(4-羟基-3-甲氧基苯基)-2-(2-甲氧基-4-(1(E)-丙烯基)苯氧基)-丙烷-1-醇(9)、nectandrin B(10)、β-谷甾醇(11)和胡萝卜苷(12)。化合物4~6和8~12为首次自该植物中分离得到,化合物4~6为首次从该属植物中分离得到。