Asymbiotic Seed Germination and in vitro Seedling Rapid Development of Paphiopedilum spicerianum

In this paper, we studied the asymbiotic seed germination and seedling development of Paphiopedilum spicerianum, a wild plant with extremely small populations (PSESP) in China. By analogizing the influences of different media, seed maturity, pretreatments and lights on the seed germination, the results showed that the best germination condition is using the seeds at 270 days after pollination, pretreating with 1% NaOCl for 40 min, on the 1/4MS+10% coconut water medium under 24 hours darkness for 4 weeks. For seedling formation, 30g·L-1 Hyponex No 1 medium with 10mg·L-1 α naphthlene acetic acid, 05g·L-1 activated charcoal and 10% banana homogenate was the most effective. For seedling development, the same medium used for seedling formation with supplemented 10g·L-1 6 benzyladenine was most suitable.     

基于GC-MS和UPLC-QTOF/MS技术的灵芝孢子粉化学成分分析

采用极性不同的6种溶剂（石油醚、乙酸乙酯、丙酮、乙醇、甲醇和水）、按索氏提取法逐级萃取破壁灵芝孢子粉,并同时运用气相色谱-质谱联用（GC/MS）和超高效液相串联四极杆飞行时间质谱（UPLC-QTOF/MS）技术对各萃取物进行化学成分分析与鉴定。结果表明：GC/MS共鉴定出101种化合物,其中酸类10种、酯类40种、醇类7种、酮类6种、酚类2种、烃类18种、甾类9种和杂原子化合物9种;UPLC-Q-TOF/MS共推断出40种化合物,其中倍半萜类1种、二萜类1种、三萜类9种、生物碱类4种、酰胺类7种、有机酸类9种以及其他化合物9种。两种测定方法间共有化合物仅1种,仅存在于5种有机溶剂（石油醚、乙酸乙酯、丙酮、乙醇和甲醇）萃取物之一的化合物共105种,2种或2种以上萃取物共有的化合物共31种,实验方法较好地实现了样品中化合物组分的充分分离,扩大了可检测化合物的范围。研究结果为灵芝孢子粉中化学成分的系统分析与鉴定、及灵芝孢子粉的化合物谱图库的完善提供了基础资料,为相关药理、药效分析及灵芝的药用模式真菌研究提供参考。     

Threading with chemostructural restrictions method for predicting fold and functionally significant residues: application to dipeptidylpeptidase IV (DPP-IV)

We present a new method for more accurate modeling of protein structure, called threading with chemostructural restrictions. This method addresses those cases in which a target sequence has only remote homologues of known structure for which sequence comparison methods cannot provide accurate alignments. Although remote homologues cannot provide an accurate model for the whole chain, they can be used in constructing practically useful models for the most conserved-and often the most interesting-part of the structure. For many proteins of interest, one can suggest certain chemostructural patterns for the native structure based on the available information on the structural superfamily of the protein, the type of activity, the sequence location of the functionally significant residues, and other factors. We use such patterns to restrict (1) a number of possible templates, and (2) a number of allowed chain conformations on a template. The latter restrictions are imposed in the form of additional template potentials (including terms acting as sequence anchors) that act on certain residues. This approach is tested on remote homologues of alpha/beta-hydrolases that have significant structural similarity in the positions of their catalytic triads. The study shows that, in spite of significant deviations between the model and the native structures, the surroundings of the catalytic triad (positions of C(alpha) atoms of 20-30 nearby residues) can be reproduced with accuracy of 2-3 A. We then apply the approach to predict the structure of dipeptidylpeptidase IV (DPP-IV). Using experimentally available data identifying the catalytic triad residues of DPP-IV (David et al., J Biol Chem 1993;268:17247-17252); we predict a model structure of the catalytic domain of DPP-IV based on the 3D fold of prolyl oligopeptidase (Fulop et al., Cell 1998;94:161-170) and use this structure for modeling the interaction of DPP-IV with inhibitor.     

利用RNA干扰抑制具有多种剪接形式的RNA结合蛋白基因的表达

目的:构建具有多种剪接形式的RNA结合蛋白(RBPMS)基因siRNA的真核表达载体,观察其对RBPMS表达的影响。方法:利用RNA干扰(RNAi)技术,设计并合成了2条针对RBPMS基因的siRNA,将其克隆到siRNA表达载体pSliencer2.1-U6neo上。将重组质粒和带FLAG标签的RBPMS共转染293T人胚肾细胞,通过Western印迹检验RNAi效应。结果:测序证明成功构建了RBPMSsiRNA真核表达载体;Western印迹表明构建的siRNA能有效地抑制RBPMS基因的表达。结论:构建了RBPMSsiRNA的真核表达载体,该siRNA能有效地抑制RBPMS基因的表达。     

强化饮食结合量化运动处方干预对IFG人群胰岛素抵抗的影响

目的探讨强化饮食结合运动处方干预对空腹血糖受损(IFG)人群胰岛素抵抗的影响。方法采取前瞻性观察研究方法,将2个社区150例IFG人群随机分成对照组和实验组进行为期3年的干预。其中实验组进行强化饮食结合量化运动处方干预,对照组不给予任何干预,观察两组患者各生化指标及胰岛素抵抗指数、胰岛素敏感指数。结果 (1)干预1年后,两组比较,FINS、IR差异无统计学意义(P0.05);TC、TG、HDL、LDL、血压、体重、腰臀比、ISI比较,差异有统计学意义(P0.05)。(2)干预3年后,两组各指标比较,差异均有统计学意义(P0.05),且较第1年有所改善。结论通过长期强化饮食结合量化运动处方干预,可降低IFG人群的胰岛素抵抗。     

旱作转BADH基因水稻旗叶、不定根解剖结构的研究

用石蜡切片法比较研究了6个水稻品系(品种)52-7、51-15、51-22、中8、开系7、白珍珠的旗叶、上层不定根的显微结构。结果表明,转BADH基因水稻品系(品种)旗叶叶片及其角质层比中8、开系7相对较厚,叶肉细胞层数及主脉维管束数比中8、开系7的多。转BADH基因水稻品系叶鞘的维管束数、气腔数目比中8、开系7、白珍珠多,其外表皮角质层比中8、开系7、白珍珠相对较厚,其维管束面积与中8、开系7、白珍珠相差不大。除51-15外,6个水稻品系(品种)上层不定根的大导管数基本相同,转BADH基闪水稻品系的小导管数较多,大、小导管的面积和以及导管的总面积和均大于中8和白珍珠,皮层比中8、开系7、白珍珠相对较薄。转BADH基因水稻品系的上述结构特征说明其旗叶生产的光合产物可满足穗部籽粒充实的需要,上层不定根发达的维管组织有利于根部水、无机盐的向上运输,提高物质运输量,为高产奠定了物质基础。     

Interactions of the cytotoxic RNase A dimers with the cytosolic ribonuclease inhibitor

Ribonuclease A (RNase A) dimers have been recently found to be endowed with some of the special, i.e., non-catalytic biological activities of RNases, such as antitumor and aspermatogenic activities. These activities have been so far attributed to RNases which can escape the neutralizing action of the cytosolic RNase inhibitor (cRI). However, when the interactions of the two cytotoxic RNase A dimers with cRI were investigated in a quantitative fashion and at the molecular level, the dimers were found to bind cRI with high affinity and to form tight complexes.     

Molecular defects in cytochrome oxidase in mitochondrial diseases

Defects of cytochromec oxidase (COX) show remarkable clinical, biochemical, and genetic heterogeneity. Clinically, there are two main groups of disorders, one dominated by muscle involvement, the other by brain dysfunction. Biochemically, the enzyme defect may be confined to one or a few tissues (reflecting the existence of tissue-specific isozymes) or affect all tissues. Immunologically reactive enzyme protein is decreased in some forms of COX deficiency but not in others. Because COX is encoded both by nuclear and by mitochondrial genes, COX deficiencies may be due to mutations of either genome and may offer useful models to study the communication between nuclei and mitochondria. We have isolated full-length cDNA clones encoding human COX subunits IV, Vb, and VIII and a partial-length clone for subunit Va. These clones are being used as probes to analyze the DNA and RNA of patients with COX deficiency.     

Three-phase extraction and partitioning with the aid of dialysis – a new method for purification of indolyI-3-acetic and abscisic acids in plant materials

A three-phase partitioning method to separate indolyl-3-acetic acid (IAA) and abscisic acid (ABA) from a crude plant extract was developed and evaluated. The aqueous phase at pH 2.7 of a methanolic plant extract constituted the 1st phase, from which IAA and ABA were transferred via diethyl ether, the 2nd phase, to a 3rd phase consisting of an alkaline buffer, enclosed in a dialysis tube. Partitioning of the free forms of the two hormones among the three phases in one container were carried out simultaneously and efficiently. The method also proved to be satisfactory when used as a combined step for both extraction and partitioning, at which the plant homogenate in buffer at pH 2.7 constituted the 1st phase. The content of IAA and ABA in kernels of Zea mays and in hypocotyls of Beta vulgaris were tested with the new method. The method presented is reliable and time-saving, and the demand for chemicals is less than for most of the conventional procedures used.