盾叶薯蓣类原球茎的离体诱导及快繁体系的建立

为解决盾叶薯蓣离体培养中试管苗移栽困难的难题,以盾叶薯蓣带腋芽的茎段为外植体,借助正交试验设计方法,离体诱导出类原球茎并建立了类原球茎微繁殖技术体系。结果表明:以带腋芽茎段为外植体诱导致密愈伤组织的适宜培养基为MS+6-BA2.0mg/L+NAA0.4mg/L+KT0.6mg/L+蔗糖3%;类原球茎诱导和增殖培养基为:MS+6-BA4.0mg/L+KT1.0mg/L+蔗糖6%;类原球茎生根培养基:1/2MS+NAA 0.3mg/L+IAA 0.8mg/L+活性炭0.3%+蔗糖1.5%。经该途径诱导得到的生根类原球茎植株经炼苗后移栽的成活率可达到90%以上。     

Partial venom gland transcriptome of a Drosophila parasitoid wasp, Leptopilina heterotoma, reveals novel and shared bioactive profiles with stinging Hymenoptera

Analysis of natural host-parasite relationships reveals the evolutionary forces that shape the delicate and unique specificity characteristic of such interactions. The accessory long gland-reservoir complex of the wasp Leptopilina heterotoma (Figitidae) produces venom with virus-like particles. Upon delivery, venom components delay host larval development and completely block host immune responses. The host range of this Drosophila endoparasitoid notably includes the highly-studied model organism, Drosophila melanogaster. Categorization of 827 unigenes, using similarity as an indicator of putative homology, reveals that approximately 25% are novel or classified as hypothetical proteins. Most of the remaining unigenes are related to processes involved in signaling, cell cycle, and cell physiology including detoxification, protein biogenesis, and hormone production. Analysis of L. heterotoma's predicted venom gland proteins demonstrates conservation among endo- and ectoparasitoids within the Apocrita (e.g., this wasp and the jewel wasp Nasonia vitripennis) and stinging aculeates (e.g., the honey bee and ants). Enzyme and KEGG pathway profiling predicts that kinases, esterases, and hydrolases may contribute to venom activity in this unique wasp. To our knowledge, this investigation is among the first functional genomic studies for a natural parasitic wasp of Drosophila. Our findings will help explain how L. heterotoma shuts down its hosts' immunity and shed light on the molecular basis of a natural arms race between these insects.     

Highly-efficient somatic embryogenesis from cell suspension cultures of phalaenopsis orchids by adjusting carbohydrate sources

Summary The influences of various carbohydrate sources, dried yeast (DY), and 6-benzylaminopurine (BA) were estimated on growth and development of shoot tip-derived suspension cells of phalaenopsis orchid. Among the carbohydrates tested on Doriataenopsis cultured on gelled medium, glucose at 58.4 mM gave the highest efficiency of protocorm-like body (PLB) formation. Maltose and sorbitol only induced PLB formation without callus proliferation. Sucrose induced comparable callus proliferation to glucose but without PLB formation. In contrast, fructose resulted in half the amount of callus proliferation as occurred with glucose. Lactose was an inadequate carbon source as neither PLB formation nor callus proliferation occurred. DY enhanced cell proliferation at 0.1–1gl⁻¹ but inhibited both cell proliferation and PLB formation at 10gl⁻¹. Low BA (0.4 μM) slightly increased callus proliferation but inhibited PLB formation. Only one treatment, sucrose and 1 gl⁻¹ DY, yielded a small number of plants. For suspension cultures of Phalaenopsis Snow Parade and P. Wedding Promenade, PLB formation was most efficiently induced by sucrose at 29.2 mM for P. Snow Parade and 14.6 mM glucose for P. Wedding Promenade. Histological observation revealed that cells in suspension culture developed into plants through the same developmental proess as germinating seeds.     

NMR solution structure and topological orientation of monomeric phospholamban in dodecylphosphocholine micelles

Phospholamban is an integral membrane protein that regulates the contractility of cardiac muscle by maintaining cardiomyocyte calcium homeostasis. Abnormalities in association of protein kinase A with PLB have recently been linked to human heart failure, where a single mutation is responsible for dilated cardiomyopathy. To date, a high-resolution structure of phospholamban in a lipid environment has been elusive. Here, we describe the first structure of recombinant, monomeric, biologically active phospholamban in lipid-mimicking dodecylphosphocholine micelles as determined by multidimensional NMR experiments. The overall structure of phospholamban is "L-shaped" with the hydrophobic domain approximately perpendicular to the cytoplasmic portion. This is in agreement with our previously published solid-state NMR data. In addition, there are two striking discrepancies between our structure and those reported previously for synthetic phospholamban in organic solvents: a), in our structure, the orientation of the cytoplasmic helix is consistent with the amphipathic nature of these residues; and b), within the hydrophobic helix, residues are positioned on two discrete faces of the helix as consistent with their functional roles ascribed by mutagenesis. This topology renders the two phosphorylation sites, Ser-16 and Thr-17, more accessible to kinases.     

(1)H/(15)N heteronuclear NMR spectroscopy shows four dynamic domains for phospholamban reconstituted in dodecylphosphocholine micelles

We report the backbone dynamics of monomeric phospholamban in dodecylphosphocholine micelles using (1)H/(15)N heteronuclear NMR spectroscopy. Phospholamban is a 52-amino acid membrane protein that regulates Ca-ATPase in cardiac muscle. Phospholamban comprises three structural domains: a transmembrane domain from residues 22 to 52, a connecting loop from 17 to 21, and a cytoplasmic domain from 1 to 16 that is organized in an "L"-shaped structure where the transmembrane and the cytoplasmic domain form an angle of approximately 80 degrees (Zamoon et al., 2003; Mascioni et al., 2002). T(1), T(2), and (1)H/(15)N nuclear Overhauser effect values measured for the amide backbone resonances were interpreted using the model-free approach of Lipari and Szabo. The results point to the existence of four dynamic domains, revealing the overall plasticity of the cytoplasmic helix, the flexible loop, and part of the transmembrane domain (residues 22-30). In addition, using Carr-Purcell-Meiboom-Gill-based experiments, we have characterized phospholamban dynamics in the micros-ms timescale. We found that the majority of the residues in the cytoplasmic domain, the flexible loop, and the first ten residues of the transmembrane domain undergo dynamics in the micros-ms range, whereas minimal dynamics were detected for the transmembrane domain. Hydrogen/deuterium exchange factors measured at different temperatures support the existence of slow motion in both the loop and the cytoplasmic helix. We propose that these dynamic properties are critical factors in the biomolecular recognition of phospholamban by Ca-ATPase and other interacting proteins such as protein kinase A and protein phosphatase 1.     

大薯类原球茎的离体诱导及再生体系的建立

采用正交试验设计方法,以大薯带节茎段为外植体,离体诱导类原球茎并建立大薯类原球茎的再生体系,以解决愈伤组织分化成苗和试管苗移栽成活率低的难题。结果表明：以带节茎段为外植体诱导类原球茎的最适培养基为MS（含3×Ca2＋）＋1.0 mg·L-1 6-BA＋0.2 mg·L-1 NAA＋0.1%PVP＋3%蔗糖,诱导率高达93.33%;类原球茎增殖的最适培养基为MS＋4mg·L-1 6-BA＋80 mg·L-1 Ad＋0.1%PVP＋3%蔗糖;类原球茎生根的最适培养基：1/2MS＋0.10 mg·L-1 NAA＋0.1%PVP＋3%蔗糖。将诱导得到的生根类原球茎植株进行炼苗,移栽基质珍珠岩：蛭石=2：1,移栽成活率可达到95%。     

Luminol‐dependent chemiluminescence of human phagocyte cell lines: comparison between DMSO differentiated PLB 985 and HL 60 cells

The human promyelocytic leukemia HL 60 and PLB 985 cell lines can differentiate into terminally mature neutrophil‐like cells via dimethyl sulfoxide (DMSO) induction. In this study the luminol‐dependent chemiluminescence (LCL) of both neutrophil‐like cells was analayzed and compared in response to phorbol myristate acetate (PMA) and opsonized zymosan (OZ) stimulants. It was shown that, like human blood neutrophils, both neutrophil‐like cells expressed high levels of CD11b, but unlike human blood neutrophils these cells almost lack LCL‐detectable intracellular oxidase activity. By studying the pattern of activation to OZ and PMA and priming with GM‐CSF, we concluded that there is no difference between the percentage of differentiation and function of DMSO‐induced HL 60 and PLB 985. However, the LCL capacity (area under the curve) of DMSO induced PLB 985 cells was higher than that of HL 60 cells in response to both PMA and OZ, which implies a higher capacity to generate reactive oxygen species in PLB 985 cells. Copyright © 2009 John Wiley & Sons, Ltd.     

四种添加物对铁皮石斛原球茎生长及多糖含量的影响

为探讨铁皮石斛(Dendrobium officinale)培养基中添加物的作用,在1/2MS培养基中加入椰肉、甘蔗渣、香蕉皮和麦麸等4种添加物,研究不同浓度添加物和培养时间对原球茎生长和多糖含量的影响。结果表明,4种添加物对铁皮石斛原球茎的增殖、分化和多糖含量均有一定影响,其中添加15.0 g L–1甘蔗渣,培养60 d能明显促进铁皮石斛原球茎的增殖与分化(146.1%);而添加20.0 g L–1甘蔗渣,培养40 d能显著提高铁皮石斛原球茎多糖含量(50.4%)。这说明甘蔗渣是培养铁皮石斛原球茎的适宜添加物,既能促进铁皮石斛原球茎的生长发育,还能降低生产成本。     

影响蝴蝶兰类原球茎耐脱水性的主要因素

为探讨蝴蝶兰(Phalaenopsis spp.)类原球茎(protocorm-like body,PLB)耐脱水性的主要影响因素,对PLB的平均粒重、含水率、脱水相对湿度、时间、温度、光周期与耐脱水性的关系进行了研究.结果表明,PLB的平均粒重与脱水后失水率、含水率、相对电导率、成活率呈显著或极显著相关.在较高湿度下...