花生种子耐脱水力的形成与可溶性糖累积的关系

花生胚轴的耐脱水力在４０－６５ＤＡＰ的发育后期逐渐增加,同时胚轴还原性糖／非还原性糖比值下降。缓慢干燥可同时诱导３５ＤＡＰ胚轴累积蔗糖与寡糖;外源ＡＢＡ及高渗处理可诱导３５ＤＡＰ离体胚轴累积蔗糖,但不能累积寡糖。耐脱水胚轴可溶性糖成分的模拟混合物可在水活度０．３２及零上温度进入玻璃太;而不耐脱水胚轴的可溶性糖模拟混合物仅在零下温度进入玻璃态。     

在蔗糖预培养诱导耐脱水性过程中黄皮胚轴的水分状态和可溶性蛋白含量的变化

逐步增加培养基的蔗糖浓度可提高黄皮胚轴的耐脱水性。用差示扫描量热仪（DSC）和SDS—PAGE方法探讨了黄皮胚轴在耐脱水性获得过程中的水分状态和可溶性蛋白的变化。DSC图谱显示,蔗糖预培养胚轴的升温图谱与对照不同,有比较明显的台阶式变化,有玻璃化形成的倾向;应用线性回归方程法或冰熔化热法计算黄皮胚轴的不可冻结水,发现蔗糖预培养胚轴的不可冻结水含量与对照胚轴无显著差异。蛋白分析表明,蔗糖预培养诱导黄皮胚轴中可溶性蛋白增加68％,其中尤以20kD蛋白的增幅最大。     

花生种子耐脱水力的获得与热稳定蛋白的关系

花生（ＡｒａｃｈｉｓｈｙｐｏｇａｅａＬ．）种子的耐脱水能力在果针入土后４５ｄ以后的胚胎发育期逐渐增加,与一组９～１５．５ｋＤ低分子量热稳定蛋白的丰富表达有关。缓慢干燥可以诱导不耐脱水的果针入土后２５ｄ及３５ｄ花生胚获得耐脱水能力并同时诱导胚轴表达这组热稳定蛋白。成熟脱水促进花生胚耐脱水能力的获得,并增加了花生球蛋白的热稳定性。     

黄皮种子脱水敏感性与胚轴可溶性糖含量的关系

以典型的顽拗性种子黄皮为试材,研究了花后不同时间的种子,收获后萌发的各及15度湿藏种子的脱水敏感性变化及其与种子胚轴中可溶性糖含量的关系。15度湿藏1、50d及600d使种子脱水敏感性增强,与寡糖含量下降以至消失及寡糖／蔗糖（O／D）之比下降极为一致,虽然花后67d的种子耐脱水能力最强,但此时蔗糖,寡糖含量及寡糖／蔗糖之比却并非最高。,虽然15度湿藏150d的种子萌发4d最耐脱水,但寡糖含量及寡糖／蔗糖之比在萌发3d时均已降至0。结果表明,发育及萌发种子的脱水敏感性与蔗糖,寡糖含量及O／D比无直接关系。     

黄皮种子脱水敏感性与胚轴中可溶性糖含量的关系

以典型的顽拗性种子黄皮为试材,研究了花后不同时间的种子、收获后萌发的种子及15℃湿藏种子的脱水敏感性变化及其与种子胚轴中可溶性糖含量的关系.15℃湿藏150d及600d使种子脱水敏感性增强,与寡糖含量下降以至消失及寡糖/蔗糖(O/D)之比下降极为一致,虽然花后67d的种子耐脱水能力最强,但此时蔗糖、寡糖含量及寡糖/蔗糖之比却并非最高.虽然15℃湿藏150d的种子萌发4d最耐脱水,但寡糖含量及寡糖/蔗糖之比在萌发3d时均已降至0.结果表明,发育及萌发种子的脱水敏感性与蔗糖、寡糖含量及O/D比无直接关系.     

种子中的棉子糖半乳糖苷系列寡糖研究进展

棉子糖半乳糖苷系列寡糖广泛分布在许多种植物种子中,并存在于干燥后仍能保持活力的组织内,如禾谷类种子的胚及糊粉层,豆类及其他双子叶植物的子叶和胚轴组织等。棉子糖半乳糖苷系列寡糖在禾谷类种子的非自溶性中央胚乳中不合成,但存在于蓖麻种子的自溶性胚乳细胞中。棉子糖半乳糖苷系列寡糖在种子发育后期累积,并持续到种子大量成熟直到脱水阶段。棉子糖半乳糖苷系列寡糖主要包括棉子糖、水苏糖和毛蕊花糖,是种子中最广泛的低分子量α_半乳糖苷。许多植物正常性种子的发育伴随着棉子糖半乳糖苷系列寡糖的累积,这些糖的累积已被认为在种子脱水耐性获得、种子活力、糖的运输及植物的抗冷驯化等过程 中起重要作用。本文从种子的脱水耐性获得、植物的冷驯化、细胞内定位及生物合成等方面综述了棉子糖半乳糖苷系列寡糖的研究进展。     

Ca2+、ABA预处理蝴蝶兰类原球茎的脱水保护系统比较及信号传导关系

CaCl2和ABA溶液及两者联合分别预处理蝴蝶兰类原球茎(PLB)后脱水,对比PLB脱水前后的成活率、脱水保护系统指标变化及Ca2+与ABA信号传导关系.结果表明,CaCl2和ABA溶液及两者联合预处理均能明显提高PLB脱水后的成活率.CaCl2和ABA溶液对可溶性糖、蔗糖、还原糖、SOD和总抗氧化能力有相同的效应趋势,对可溶性蛋白、热稳定蛋白含量及POD、CAT活性的作用趋势有所差异.ABA溶液提高PLB耐脱水性的能力被胞质Ca2+ 螯合剂BAPTA/AM 和钙调蛋白拮抗剂氯丙嗪所削弱,Ca2+预处理提高PLB耐脱水能力被ABA合成抑制剂环丙嘧啶醇削弱.在蝴蝶兰PLB的耐脱水性诱导中,Ca2+和ABA具有基本相同的生理生化基础,在信号传递中两者互相关联,CaCl2取代ABA用于提高PLB耐脱水性是可行的.     

油菜（Brassica napus L.）种子脱水耐性获得过程中肌醇半乳糖苷合成酶活性与可溶性糖含量的变化

在这个研究中测量不同发育时期的油菜种子中可溶性糖含量与肌醇半乳糖苷合成酶（galactinol synthase,GOLS）活性,将二者的变化趋势与种子脱水耐性获得的过程相比较并对结果进行相关性分析。结果显示油菜种子脱水耐性获得过程中,葡萄糖和果糖含量均随着发育期的延长而下降,蔗糖则保持较高水平;肌醇含量下降而肌醇半乳糖苷含量上升;棉子糖系列寡糖（raffinose familyolig osaccharides,RFO）含量随着种子发育而上升,特别是水苏糖,在成熟种子中可以达到相当高的浓度。油菜种子发育中期,细胞内GOLS活性开始上升,至贮藏物积累完成时达到最大。GOLS活性变化与种子肌醇半乳糖苷积累速度、RFO含量及种子的脱水耐性呈一定的正相关关系。我们认为GOLS促使RFO积累,从而对种子脱水耐性的获得产生重要影响。     

表油菜素内酯对油菜幼苗生长及其可溶性糖和蛋白质含量的影响(简报)

表油菜素内酯（epiBR）处理油菜幼苗，可明显促进下胚轴伸长生长，增加子叶面积，同时降低蛋白质含量及子叶中可溶性糖含量。SDS－PAGE检测分白结果表明，epiBR处理后，下胚轴和子叶中的蛋白组分均发生明显的改变。     

He—Ne激光对UV—B辐射小麦幼苗糖代谢的影响

分别采用5 mW·mm-2 He-Ne激光辐照、10.08 kJ·m-2·d-1 增强UV-B辐射及二者组合对"晋麦8号"小麦幼苗进行处理,测定各处理幼苗叶片可溶性糖、还原性糖、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS) 以及α,β-淀粉酶的变化.研究分析He-Ne激光对增强UV-B辐射引起小麦损伤的修复效应.结果表明:He-Ne激光辐照可使UV-B辐射后小麦幼苗可溶性糖含量升高,还原性糖含量降低,SS,SPS活力降低,α,β-淀粉酶活力升高.该结果同时表明可溶性糖、还原性糖、SS、SPS、α,β-淀粉酶的变化同小麦幼苗损伤修复的能力相关,一定剂量的He-Ne激光辐照可部分修复增强UV-B对小麦幼苗糖代谢的辐射损伤.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.