一粒系小麦种质资源研究进展

一粒系小麦是多倍体小麦染色体组的供体物种之一,是小麦的重要基础物种。近年来,随着现代生物技术的应用,国际上对一粒系小麦的研究取得了较大进展,但至今我国对一粒系小麦的研究和利用仍相对较少。本文从分布与分类、起源与进化、细胞学、遗传学、生物化学、分子生物学、生理学、农艺和品质性状等方面,将国内外对一粒系小麦种质资源的研究进展进行了综述,以期为一粒系小麦的进一步研究和利用提供参考。     

Pigment Cell Differentiation in Sea Urchin Blastula-Derived Primary Cell Cultures

The quinone pigments of sea urchins, specifically echinochrome and spinochromes, are known for their effective antioxidant, antibacterial, antifungal, and antitumor activities. We developed in vitro technology for inducing pigment differentiation in cell culture. The intensification of the pigment differentiation was accompanied by a simultaneous decrease in cell proliferation. The number of pigment cells was two-fold higher in the cells cultivated in the coelomic fluids of injured sea urchins than in those intact. The possible roles of the specific components of the coelomic fluids in the pigment differentiation process and the quantitative measurement of the production of naphthoquinone pigments during cultivation were examined by MALDI and electrospray ionization mass spectrometry. Echinochrome A and spinochrome E were produced by the cultivated cells of the sand dollar Scaphechinus mirabilis in all tested media, while only spinochromes were found in the cultivated cells of another sea urchin, Strongylocentrotus intermedius. The expression of genes associated with the induction of pigment differentiation was increased in cells cultivated in the presence of shikimic acid, a precursor of naphthoquinone pigments. Our results should contribute to the development of new techniques in marine biotechnology, including the generation of cell cultures producing complex bioactive compounds with therapeutic potential.     

Cytotoxic Effects of Fascaplysin against Small Cell Lung Cancer Cell Lines

Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4) inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC) cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS) and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose)-Polymerase 1 (PARP1) inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS.     

水稻糊粉层PCD过程细胞形态观察

糊粉层细胞程序性死亡(programmed cell death,PCD)是水稻(Oryza Sativa L.)种子萌发过程中的关键事件。为探明水稻糊粉层细胞程序性死亡过程中细胞形态的变化,利用荧光显微技术结合染色方法对不同萌发时间的水稻种子糊粉层细胞形态进行了观察。结果显示:糊粉层细胞死亡过程中液泡呈现2种变化类型,液泡化的最终形态也有所差异;糊粉层细胞死亡的发生与液泡化程度紧密联系,并且与胚的生长及距离有明显的时间效应和位置效应。     

水稻不育系T55A异交结实特性研究

对水稻不育系T55A异交特性研究表明,T55A午前花率高(84.07%),花时较早(07:30始花),开花集中,且柱头活力强,但异交结实率受环境影响较大.     

水稻不育系T55A的特性及所配组合的种植表现和利用评价

针对特A育性不稳定而进行遗传改良育成的新不育系T55A,其农艺性状、异交特性和配合力与特A相近;分期播种试验结果,T55A镜检可染花粉率不超过0O．1％,而特A8期中有5期可染花粉率超过5％;制种实践表明,T优158的种子纯度比特优158平均高3．7个百分点,T优898的种子纯度比特优898平均高2．8个百分点。利用T55A已配组育成了T优5537、T优5570、T优551、T优55898、T55优627、T优158等6个杂交水稻新组合,这些组合已相继通过了国家或省级审定。目前T55系列组合已成为福建省龙岩市的主栽品种。     

乌拉尔图和栽培一粒小麦抗病基因向普通小麦转移的研究

乌拉尔图小麦（Triticum urartu Tum．）和栽培一粒小麦（Triticum monococcum L．）是普通小麦的两个二倍体野生种，是进行小麦遗传改良的重要遗传资源。为了将其抗白粉病和抗条锈病基因转移到普通小麦中，用普通小麦分别与两份乌拉尔图小麦材料1010013和1010015及一份栽培一粒小麦材料1010048配制杂交组合。结果表明，乌拉尔图小麦与普通小麦杂交不能正常结实，必须进行幼胚拯救。成胚率为14．77％；而栽培一粒小麦与普通小麦杂交可正常结实，但结实率很低。杂种F1自交不育，与普通小麦回交可正常结实．但BC1自交结实率极低。对普通小麦与乌拉尔图小麦杂种F1花粉母细胞减数分裂中期Ⅰ的观察结果表明，平均单价体为17．36个．二价体为5．32个。进一步对杂种后代进行抗病鉴定和遗传分析，乌拉尔图小麦1010013和1010015分别含有一对显性抗白粉病基因。栽培一粒小麦1010048含有两对独立遗传的显性抗条锈病基因，并分别在杂种后代BC2F1和BC1F2中获得了染色体正常（2n=42）、细胞学稳定且抗性与供体亲本一致的抗白粉病和抗备锈病植株。说明来自二倍体乌拉尔图和栽培一粒小麦的抗病基因已通过遗传重组导入到普通小麦中。研究还发现普通小麦莱州953与乌拉尔图小麦和栽培一粒小麦杂交的结实率与中国春的同样高，表明其可能携带有远缘杂交亲和基因。     

波兰小麦醇溶蛋白遗传差异及其与新疆稻麦的关系

利用酸性聚丙烯酰胺凝胶电泳（ＡＰＡＧＥ）对９份波兰小麦和２份新疆稻麦进行了醇溶蛋白分析。结果表明：⑴波兰小麦具有明显的醇溶蛋白多态性,９份材料具有７种醇溶蛋白带型,电泳分离出的２７条带中,２３条具有多态性;⑵供试波兰小麦间遗传距离在０－０．７５之间,平均值为０．４９,遗传变异较大。供试波兰小麦在遗传距离０．４９水平上聚为３类,其醇溶蛋白聚类与收集地关系不大;⑶新疆稻麦与波兰小麦的醇溶蛋白电泳图谱具     

香荚兰细胞培养及产香兰素研究初报

香荚兰的幼茎在MS＋BA1μg／mL＋NAA5μg／mL培养基上培养40d,其表面形成白色、块状的愈伤组织。愈伤组织在MS＋2,4－D1μg／mL＋BA1μg／mL＋NAA4μg／mL＋2．5％sucrose的半固体培养基上快速增殖培养,培养4周后培养物的重量增加7倍左右;在相同培养基的悬浮培养中,培养4周后培养物的重量增加6～8倍。从不同的培养物中分离出香兰素并测定其含量。     

Okadaic Acid Toxin at Sublethal Dose Produced Cell Proliferation in Gastric and Colon Epithelial Cell Lines

The aim of this study was to analyze the effect of Okadaic Acid (OA) on the proliferation of gastric and colon epithelial cells, the main target tissues of the toxin. We hypothesized that OA, at sublethal doses, activates multiple signaling pathways, such as Erk and Akt, through the inhibition of PP2A. To demonstrate this, we carried out curves of doses and time response against OA in AGS, MKN-45 and Caco 2 cell lines, and found an increase in the cell proliferation at sublethal doses, at 24 h or 48 h exposure. Indeed, cells can withstand high concentrations of the toxin at 4 h exposure, the time chosen considering the maximum time before total gastric emptying. We have proved that this increased proliferation is due to an overexpression of Cyclin B, a cyclin that promotes the passage from G2 to mitosis. In addition, we have demonstrated that OA induces activation of Akt and Erk in the three cells lines, showing that OA can activate pathways involved in oncogenesis. In conclusion, this study contributes to the knowledge about the possible effects of chronic OA consumption.     

Cytotoxic Effect of Natural trans-Resveratrol Obtained from Elicited Vitis vinifera Cell Cultures on Three Cancer Cell Lines

trans-Resveratrol (trans-R) has been reported to be a potential cancer chemopreventive agent. Although its cytotoxic activity against different cancer cell lines has been tested, its effect on human acute leukemia cell lines has scarcely been investigated, and only a few in vitro studies were performed using human breast epithelial cell lines. Due to its potential value for human health, demand for trans-R has rapidly increased, and new biotechnological strategies to obtain it from natural edible sources have been developed. Thus, grapevine cell cultures represent a reliable system of trans-R production since they biosynthesize trans-R constitutively or in response to elicitation. In addition, there are no studies deepen on the inhibitory effect of trans-R, produced by elicited grapevine cell cultures, on growth of human tumor cell lines. In this work, the effect of trans-R extracted from the culture medium, after elicitation of grapevine cell cultures, was tested on two human acute lymphocytic and monocytic leukemia cell lines, and one human breast cancer cell line. The effect of trans-R on cell proliferation was not only dose- and time-dependent but also cell type-dependent, as seen from the different degrees of susceptibility of cancer cell lines tested. As regards the effect of trans-R on cell cycle distribution, low trans-R concentrations increased cells in the S phase whereas a high trans-R concentration increased G₀/G₁ phase in all cell lines. Perturbation of the cell cycle at low trans-R concentrations did not correlate with the induction of cell death, whereas a high trans-R concentration, cell proliferation decreased as a result of increasing apoptosis in the three cell lines. In leukemia cells, trans-R up-regulated the expression of caspase-3 while trans-R-induced apoptosis in breast cells occur through a caspase-3-independent mechanism mediated by a down-regulation of Bcl-2.     

Purified Brominated Indole Derivatives from Dicathais orbita Induce Apoptosis and Cell Cycle Arrest in Colorectal Cancer Cell Lines

Dicathais orbita is a large Australian marine gastropod known to produce bioactive compounds with anticancer properties. In this research, we used bioassay guided fractionation from the egg mass extract of D. orbita using flash column chromatography and identified fractions containing tyrindoleninone and 6-bromoisatin as the most active against colon cancer cells HT29 and Caco-2. Liquid chromatography coupled with mass spectrometry (LCMS) and ¹H NMR were used to characterize the purity and chemical composition of the isolated compounds. An MTT assay was used to determine effects on cell viability. Necrosis and apoptosis induction using caspase/LDH assay and flow cytometry (PI/Annexin-V) and cell cycle analysis were also investigated. Our results show that semi-purified 6-bromoisatin had the highest anti-cancer activity by inhibiting cell viability (IC₅₀ = ~100 µM) and increasing caspase 3/7 activity in both of the cell lines at low concentration. The fraction containing 6-bromoisatin induced 77.6% apoptosis and arrested 25.7% of the cells in G2/M phase of cell cycle in HT29 cells. Tyrindoleninone was less potent but significantly decreased the viability of HT29 cells at IC₅₀ = 390 µM and induced apoptosis at 195 µM by increasing caspase 3/7 activity in these cells. This research will facilitate the development of these molluscan natural products as novel complementary medicines for colorectal cancer.     

Haloarchaea as Cell Factories to Produce Bioplastics

Plastic pollution is a worldwide concern causing the death of animals (mainly aquatic fauna) and environmental deterioration. Plastic recycling is, in most cases, difficult or even impossible. For this reason, new research lines are emerging to identify highly biodegradable bioplastics or plastic formulations that are more environmentally friendly than current ones. In this context, microbes, capable of synthesizing bioplastics, were revealed to be good models to design strategies in which microorganisms can be used as cell factories. Recently, special interest has been paid to haloarchaea due to the capability of some species to produce significant concentrations of polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), and polyhydroxyvalerate (PHV) when growing under a specific nutritional status. The growth of those microorganisms at the pilot or industrial scale offers several advantages compared to that of other microbes that are bioplastic producers. This review summarizes the state of the art of bioplastic production and the most recent findings regarding the production of bioplastics by halophilic microorganisms with special emphasis on haloarchaea. Some protocols to produce/analyze bioplastics are highlighted here to shed light on the potential use of haloarchaea at the industrial scale to produce valuable products, thus minimizing environmental pollution by plastics made from petroleum.     

植物干细胞研究进展

从近年来研究发展的植物干细胞概念、茎尖分生组织、根尖分生组织、维管形成层组织的结构特征及其各自调控的分子机制等方面进行总结,重点阐述了近年来植物干细胞在植物体内发生与分化所涉及的分子调控机制,并对植物干细胞研究的未来前景进行了展望.     

Molecular Mechanisms by Which a Fucus vesiculosus Extract Mediates Cell Cycle Inhibition and Cell Death in Pancreatic Cancer Cells

Pancreatic cancer is one of the most aggressive cancer entities, with an extremely poor 5-year survival rate. Therefore, novel therapeutic agents with specific modes of action are urgently needed. Marine organisms represent a promising source to identify new pharmacologically active substances. Secondary metabolites derived from marine algae are of particular interest. The present work describes cellular and molecular mechanisms induced by an HPLC-fractionated, hydrophilic extract derived from the Baltic brown seaweed Fucus vesiculosus (Fv1). Treatment with Fv1 resulted in a strong inhibition of viability in various pancreatic cancer cell lines. This extract inhibited the cell cycle of proliferating cells due to the up-regulation of cell cycle inhibitors, shown on the mRNA (microarray data) and protein level. As a result, cells were dying in a caspase-independent manner. Experiments with non-dividing cells showed that proliferation is a prerequisite for the effectiveness of Fv1. Importantly, Fv1 showed low cytotoxic activity against non-malignant resting T cells and terminally differentiated cells like erythrocytes. Interestingly, accelerated killing effects were observed in combination with inhibitors of autophagy. Our in vitro data suggest that Fv1 may represent a promising new agent that deserves further development towards clinical application.     

茶儿茶素对癌细胞凋亡作用的研究

本文研究茶儿茶素诱导白血病癌细胞凋亡的作用及其机理。结果表明 ,茶儿茶素 (包括EGCG ,ECG和EGC)在浓度超过 5 0 μg ml时促进白血病癌细胞的凋亡 ,并在 5 0～ 30 0 μg ml浓度范围内存在正的量 -效关系。茶儿茶素诱导癌细胞凋亡的可能机理之一是促进自由基的产生 ,并抑制癌细胞的抗氧化酶     

利用外源前体饲喂生物合成~(14)C-儿茶素的研究

采用在茶树细胞培养过程中饲喂标记前体的方法,进行了~(14)C标记儿茶素的合成研究。比较了~(14)C-苯丙氨酸和~(14)-乙酸钠两种前体的饲喂效果,分析了饲喂前体被培养细胞吸收与利用的动态,以及外源苯丙氨酸饲喂所带来的细胞产物组成与水平变化,并采用高速逆流色谱和高效液相色谱技术对合成的标记产物进行了分离与分析。     

Cell wall deposition and metabolism in wheat grain

There is an amazing diversity of cell wall composition and cell wall polysaccharide structure in wheat grain that is only partly explained by the complexity of plant tissues and cell type functions present in this organ. This review presents the state of the art on the structure and diversity of cell wall polymers in mature wheat grain and recent knowledge on cell wall metabolism with a focus on development-associated changes in wheat grain cell wall polysaccharides and genes controlling their biosynthesis. The diversity of polysaccharide structure observed in endosperm cell walls is tentatively explained on the basis of polysaccharide properties and cell type function.     

EGCG对细胞的促氧化作用研究进展

EGCG是茶叶中主要的儿茶素类物质,具有多种生物活性。近年来,EGCG促氧化作用得到了广泛关注。本文对国内外细胞实验中EGCG的促氧化作用进行综述。EGCG在细胞培养基中发生自动氧化可以形成细胞外氧化应激环境,这种自动氧化受到培养基种类、EGCG浓度与处理时间、血清含量及p H值等因素影响。在细胞内,EGCG直接提高细胞内活性氧(Reactive Oxidative Species,ROS)和线粒体ROS,或者通过Fenton反应间接产生OH-。EGCG可以影响细胞内转录因子、信号通路与表面生长因子受体的表达与传递,从而影响细胞的一系列生命活动。