宁夏枸杞果皮蜡质微形态及蜡质组分研究北大核心CSCD

果实制干是宁夏枸杞炮制的主要过程,宁夏枸杞不同品种在制干特性方面存在一定的差异。该研究以宁夏枸杞栽培中制干差异较大的品种‘宁杞1号’(易制干)和‘宁杞5号’(不易制干)果实为材料,采用扫描电镜技术和GC-MS技术对2个宁夏枸杞品种不同发育时期(青果期、色变期、成熟期)的果实果皮结构以及果皮蜡质微形态、含量和组分进行了观测,从果皮蜡质微形态及组分的积累变化初步揭示枸杞果皮蜡质的积累规律,以明确不同枸杞品种果皮蜡质组分差异,为不同品种适宜促干剂的筛选以及促干剂的合理使用提供理论依据。结果表明:(1)‘宁杞1号’和‘宁杞5号’枸杞表皮细胞外侧细胞壁均呈现脊状突起的结构,在果实青果期脊状突起不连续,脊和脊之间排列紧密;随着发育时期的延后,脊状突起的连续性逐渐增强,且脊与脊之间的间距逐渐变宽,蜡质呈膜状覆盖于凸起的脊和两脊之间的沟内。(2)‘宁杞1号’和‘宁杞5号’两个枸杞品种在果实发育过程中,果皮单位面积蜡质含量均呈先下降后上升的趋势,在成熟期单位面积蜡质含量最高,且‘宁杞1号’3个发育时期果皮单位面积蜡质含量均高于同期‘宁杞5号’,呈现出与扫描电镜观察到的蜡质分布基本一致的变化趋势。(3)2个品种3个时期的果实表皮蜡质组分均由烷烃类、酮类、醇类、酸类、醛类、酯类和碘代烷烃类组成,两品种青果期和色变期果皮蜡质组分相同,主要由烷烃类、醇类和碘代烷烃类组成,它们成熟期的果皮蜡质组分主要由烷烃类、醇类和酯类组成。(4)主成分分析结果显示,3个生育时期‘宁杞5号’果皮蜡质组分多为烷烃类物质,较‘宁杞1号’更利于阻挡果实水分的散失。研究发现,影响枸杞果实制干的原因在于枸杞果皮蜡质含量、结构和蜡质组分,烷烃类组分能够有效阻止果实体内水分的散失,‘宁杞5号’果皮蜡质中烷烃组分含量更高,果皮保水性更强,致果实不易制干。     

miR-888 is an expressed prostatic secretions-derived microRNA that promotes prostate cell growth and migration

microRNAs (miRNAs) are a growing class of small non-coding RNAs that exhibit widespread dysregulation in prostate cancer. We profiled miRNA expression in syngeneic human prostate cancer cell lines that differed in their metastatic potential in order to determine their role in aggressive prostate cancer. miR-888 was the most differentially expressed miRNA observed in human metastatic PC3-ML cells relative to non-invasive PC3-N cells, and its levels were higher in primary prostate tumors from cancer patients, particularly those with seminal vesicle invasion. We also examined a novel miRNA-based biomarker source called expressed prostatic secretions in urine (EPS urine) for miR-888 expression and found that its levels were preferentially elevated in prostate cancer patients with high-grade disease. These expression studies indicated a correlation for miR-888 in disease progression. We next tested how miR-888 regulated cancer-related pathways in vitro using human prostate cancer cell lines. Overexpression of miR-888 increased proliferation and migration, and conversely inhibition of miR-888 activity blocked these processes. miR-888 also increased colony formation in PC3-N and LNCaP cells, supporting an oncogenic role for this miRNA in the prostate. Our data indicates that miR-888 functions to promote prostate cancer progression and can suppress protein levels of the tumor suppressor genes RBL1 and SMAD4. This miRNA holds promise as a diagnostic tool using an innovative prostatic fluid source as well as a therapeutic target for aggressive prostate cancer.     

蚧虫蜡泌物的化学研究进展

总结了国内外对蚧虫蜡泌物及其化学成分的研究进展 ,内容包括蜡泌物形成介壳的主要类型 ;蜡泌物的化学研究方法及已涉及的种类 ;蜡泌物的主要化学组成 ,并对 5类物质 ,即蜡、烃类、树脂或萜类、色素类、内蜜露作了重点叙述。最后 ,讨论了研究蚧虫蜡泌物的化学成分具有的意义和应用前景 ,包括蜡泌物作为生物资源的利用 ;以蚧虫作为农林、果树和花卉业的重要害虫 ,针对蜡泌物的特点研制相应的新型杀虫剂 ;利用蜡泌物的化学信息素对天敌的诱导作用 ,开展蚧虫生物防治 ;利用蜡泌物作为化学分类性状的应用等。     

Molecular evidence for post-domestication selection in the <Emphasis Type="Italic">Waxy</Emphasis> gene of Chinese waxy maize

Waxy maize was first reported in China in 1909 and is mainly used in food production in Asia. The evidence for strong domestication selection in the Waxy locus of rice and a selective sweep around its genomic region make us to wonder whether there has been similar selection in Waxy in glutinous maize. To address this issue, DNA sequences of Waxy, three flanking genes and an unlinked gene (Adh1) of 30 accessions sampled from Chinese waxy maize accessions, including representative landraces and inbred lines, were determined in this study. Sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed in the Waxy locus in Chinese waxy maize but not in nonglutinous maize; comparison with the unlinked gene confirmed that this pattern was different to Waxy. Sequence analysis across a 143 kb genomic segment centered on the Waxy locus revealed patterns consistent with a selective sweep in the upstream region of Waxy. The selective sweep detected based on current limited genomic sequences exceeded over 50 kb, indicating strong selection in this or a bigger region. However, No sweep effect was detected in the repetitive downstream region of Waxy. Phylogenetic analysis indicated that Chinese waxy maize was domesticated from the cultivated flint maize (Zea mays ssp. mays) that was introduced from the new world. At least two independent deletions in exon 7 (30 bp) and 10 (15 bp) were identified in the Chinese accessions respectively. These findings demonstrate a similar pattern of domestication selection in the Waxy genomic region in both glutinous maize and rice, suggesting that this pattern in the rise of glutinous phenotype is likely in other cereal crops.     

利用wx基因分子标记辅助选择培育糯性小麦

利用中国春及其缺体-四体对wx-B1基因的STS标记和wx-A1、wx-D1的微卫星(SSR)标记进行了定位.联合应用这2种分子标记,对12个小麦品种和5个高代糯麦株系做了鉴定,与Wx蛋白的SDS-PAGE结果一致;从组合江苏白火麦×关东107的F2分离群体中筛选出8种wx基因型,其中3种基因型(AD同缺型,BD同缺型和糯型)为自然界中所没有,并且培育出了国内首批糯性小麦品系.另外,应用SSR标记对江苏白火麦回交改良群体中个体进行辅助选择,得到了含wx-D1b的7D单体,为将来进一步改良糯性小麦的农艺性状提供广泛的遗传材料.利用wx基因分子标记辅助选择,可以加速培育糯性小麦的进程.     

Antisense regulation of the rice waxy gene expression using a PCR-amplified fragment of the rice genome reduces the amylose content in grain starch

The waxy gene encodes a granule-bound starch synthase. A 1.0-kb portion of the sequence of the rice waxy gene, which includes the region between exon 4 and exon 9, was inserted in an antisense orientation between the 35 S promoter and the GUS gene of pBI221. The resultant plasmid, pWXA23, was introduced into rice protoplasts by electroporation. GUS activity was clearly detected in derived callus lines, suggesting that the antisense component of the fusion gene was also expressed. Transgenic rice plants were regenerated from these callus lines and their GUS activity was confirmed. Some of the rice seeds from these transformants showed a significant reduction in the amylose content of grain starch, even though they had become polyploid. These results suggest that even when intron sequences are included, antisense constructs can bring about a reduced level of expression of a target gene. The utility of GUS, included as a reporter gene, for the simple detection of expression of an antisense gene, was apparent from these results.     

水稻蜡质基因5’端上游顺序中的核蛋白结合区

通过ｗｘ基因转录起始点上游２１２０ｂｐ长的ＤＮＡ序列的测定,用不同的限制性内切酶对此片段进行消化,获得１５个大小不同的ＤＮＡ片段并构建成不同的亚克隆。这些片段经３２Ｐ标记后分别做探针同水稻不同组织来源的核蛋白进行凝胶滞后实验和特异的竞争实验,表明ＨｉｎｆＩａ－２、ＨｉｎｆＩｃ－１、ＨｉｎｆＩｃ－２、ＨｉｎｆＩｄ、ＲｓａＩａ和ＲｓａＩｅ（ＲｓａＩａ片段与ＨｉｎｆＩａ、ＨｉｎｆＩｃ片段重叠）片段能与从未成熟的水稻种子中抽提的核蛋白结合。     

Chemical defences in leaf beetles and their larvae: The ecological, evolutionary and taxonomic significance

The chemical defences of the Chrysomelinae are reviewed. Defensive glandular secretions have evolved independently in larvae and adults, and faster than the morphology of the glands. Both characters are used in a phylogenetic study of the Chrysomelini, disclosing suprageneric affinities. First, a close relationship between the Chrysomelina and Phratora is proposed. Secondly, Leptinotarsa and Gonioctena are probably more closely related to the Chrysolinina than to the Chrysomelina and Phratora. The qualitative and quantitative composition of larval and adult secretions sometimes differs between geographically isolated populations of the same species, which are therefore probably genetically distinct. The host plant shows an influence which explains discrepancies between the current classification and the chemical nature of the secretions. Some beetles sequester secondary plant metabolites or use them as precursors for their own defences. The original biosynthetic pathway has been lost in these species. Other factors which could affect the chemical diversity of the secretions are discussed: random events such as neutral mutations and genetic drift, conditioning or adaptation of predators to specific defensive mixtures, and the diversity of potential predators. The latter could help to explain the divergence in the chemical nature of the larval and adult secretions. The volatile irritants produced by the larvae are well suited to repel small arthropods, such as ants, whereas poisons associated with aposematic coloration in the adults could be directed against small vertebrates, such as birds.     

Comparative kinetics of phosphomannosyl receptor-mediated pinocytosis of fibroblast secretion acid hydrolases and glycopeptides prepared from them

In a previous report we demonstrated that phosphorylated oligosaccharides isolated from acid hydrolases were subject to pinocytosis by phosphomannosyl receptors present on the cell surface of human fibroblasts [9]. However, limiting quantities of oligosaccharides precluded detailed comparison of the kinetics of pinocytosis of these phosphorylated oligosaccharides to those of the acid hydrolases from which they were derived. In this report we present studies comparing the kinetics of pinocytosis of acid hydrolases from NH4Cl-induced fibroblast secretions with those of concanavalin A-binding glycopeptides prepared from them by pronase digestion. The uptake of both secretion acid hydrolases and 125I-labeled glycopeptides was linear for at least 3 hr, saturable, inhibited competitively by mannose 6-phosphate, and destroyed by prior treatment of the ligand with alkaline phosphatase. The inhibition constants of excess unlabeled glycopeptide for the uptake of 125I-labeled glycopeptides (Ki of 1.5 X 10(-6) M) and for the uptake of secretion acid hydrolases (Ki of 2.2 X 10(-6) M) were remarkably similar. Furthermore, the Ki for mannose 6-phosphate inhibition of pinocytosis of glycopeptide uptake (3 X 10(-5) M) compares closely to that previously determined for the pinocytosis of intact "high-uptake" acid hydrolases (3-6 X 10(-5) M). "High-uptake" fractions of both ligands were prepared and quantified by affinity chromatography on immobilized phosphomannosyl receptors purified from bovine liver. Only 10% of the concanavalin A-binding glycopeptides bound to the immobilized phosphomannosyl receptors, while 80% of the acid hydrolases from which they were prepared bound and were eluted with 10 mM mannose 6-phosphate. However, the fraction of each type of ligand that binds to the immobilized phosphomannosyl receptors accounts for all the uptake activity of that ligand.     

Antibacterial activity of larval saliva of the European paper wasp <Emphasis Type="Italic">Polistes dominulus</Emphasis> (Hymenoptera,Vespidae)

Summary. Microbiological tests demonstrated antibacterial activity (against Bacillus subtilis, Gram +, and Escherichia coli, Gram –) of larval salivary secretions of Polistes dominulus but failed to demonstrate its antifungal activity.Received 7 November 2003; revised 17 March 2004; accepted 29 March 2004.