摘要：功能的基因标记能关于功能的基因差异和微生物引起的社区的潜在的活动提供重要信息。尽管 microarray 技术成功地被使用了为纯文化学习基因表示，简单、人工的微生物引起的社区，改编如此的一种技术分析复杂微生物引起的社区仍然以设计，样品准备，和数据分析提出很多挑战。这个工作集中于功能的基因数组(FGA ) 的开发和应用程序为微生物引起的社区研究指向关键功能的基因标记。一些与 FGA 有关明确地给问题调音，例如 oligonucleotide 探查设计， nucleic 酸抽取和纯化，数据分析，特性，敏感，和量的能力详细被讨论。最近的研究证明了 FGA 能从许多自然环境关于微生物引起的社区提供特定、敏感、潜在地量的信息并且控制生态系统。这种技术被期望革命化微生物引起的社区的分析，并且连接微生物引起的结构到生态系统工作。

摘要：Single-chain repressor RRTRES is a derivative of bacteriophage 434 repressor, which contains covalently dimerized DNA-binding domains (amino acids 1-69) of the phage 434 repressor. In this single-chain molecule, the wild type domain R is connected to the mutant domain RTRES by a recombinant linker in a head-to-tail arrangement. The DNA-contacting amino acids of RTRES at the -1, 1,2, and 5 positions of the α3 helix are T, R, E, S respectively. By using a randomized DNA pool containing the central sequence -CATACAAGAAAGNNNNNNTTT-. a cyclic, in vitro DNA-binding site selection was performed. The selected population was cloned and the individual members were characterized by determining their binding affinities to RRTRES. The results showed that the optimal operators contained the TTAC or TTCC sequences in the underlined positions as above, and that the Kd values were in the 1×10-12mol/L1×10-11mol/L concentration range. Since the affinity of the natural 434 repressor to its natural operator sites is in the 1×10-9 mol/L range, the observed binding affinity increase is remarkable. It was also found that binding affinity was strongly affected by the flanking bases of the optimal tetramer binding sites, especially by the base at the 5' position. We constructed a new homodimeric single-chain repressor RrREsRtRES and its DNA-binding specificity was tested by using a series of new operators designed according to the recognition properties previously determined for the RTRES domain. These operators containing the consensus sequence GTAAGAAARNTTACN or GGAAGAAARNTTCCN (R is A or G) were recognized by RTRESRTRES specifically, and with high binding affinity. Thus, by using a combination of random selection and rational design principles, we have discovered novel, high affinity protein-DNA interactions with new specificity. This method can potentially be used to obtain new binding specificity for other DNA-binding proteins.

摘要：Main observation and conclusion An HPLC-UV-guided separation was performed and four pairs of unprecedented macathiohydantoin dimers,lepithiohydimerins A—D(1—4)bearing a rare disulfide bond were isolated from the tubers of *** structures were unambiguously confirmed by NMR spectroscopic,X-ray crystallographic and electronic circular dichroism(ECD)*** the concentration of 20μmol/L,compounds 2-1,2-2,and 4-1 increased the viability of PC12 cells with the cell viability at(72.06±1.14)%,(72.64±1.49)%,and(70.93±1.22)%,***,the serial concentration experiment showed that they can protect PC12 cells in a dose-dependent manner.

摘要：Inspired by the intriguing structures and remarkable activities of sesquiterpenoid dimers,12 new sesquiterpenoid dimers,artematrovirenolides A—D(1—4)and artematrolides S—Z(8—12),were isolated from the EtOAc fraction of Artemisia atrovirens through a bioactivity-guided *** structures were elucidated by comprehensive spectroscopic data and absolute configuration was assigned based on single crystal X-ray diffraction data and ECD ***,all compounds are presumably formed via[4+2]cycloaddition involving three connecting *** 1—4 are four novel hetero-dimeric[4+2]Diels-Alder adducts dimerized from a rotundane-type unit and a guaiane-type monomer,and compounds 5—12 are eight new homo-dimeric[4+2]adducts derived from two guaianolide moieties.A putative biosynthetic pathway for compounds 1—4 was also *** 4,6,7,and 10 demonstrated moderate cytotoxicity against HepG2,SMMC-7721,and Huh7 cell lines with IC50 values ranging from 9.3 to 62.3μmol/***,compounds 5 and 11 manifested cytotoxicity with IC50 values of 13.6 and 12.8(HepG2),18.5 and 13.1(SMMC-7721),and 16.5 and 19.4μmol/L(Huh7),respectively,which were equivalent to the positive control,*** investigation suggests that compounds 5 and 11 might be considered as potent antihepatoma candidates and deserve further structural modification and mechanism study.

摘要：Aims Bee-pollinated flowers are rarely red,presumably because bees(which lack red receptors)have difficulty detecting red *** the response of bees to red colour has been investigated in lab experiments,most stimuli have been pure red,while the subtle diversity of red as perceived by humans(human-red)has received very limited *** we test the hypothesis that ultraviolet(UV)reflected from human-red flowers enhances their attractiveness to bees,through increased chromatic *** Using Onosma confertum(Boraginaceae),a plant with UV-reflecting red flowers that are pollinated by bumblebees,we investigated the effects of UV reflection on pollinator responses by conducting phenotypic manipulation experiments in the *** preferences of flower-naïve bumblebees were also *** perception by bumblebees was estimated in terms of chromatic and achromatic contrast,based on two different colour perception *** Findings We found that both natural and flower-naïve bumblebees strongly preferred visiting UV-reflecting targets compared with UV-absorbing *** models show that the UV-reflecting flowers exhibit higher spectral purity and higher chromatic contrast against the foliage background,whereas they have similar achromatic contrast in terms of green receptor *** results indicate that the component of UV reflection increases chromatic contrast in ***,enhancing the visual attractiveness of these red flowers to *** further infer that the secondary reflectance might be a necessary component in human-red flowers that are primarily pollinated by animals without red receptors,such as bees.

摘要：The visualization of the surface of biological samples using an atomic force microscope reveals features of the external relief and can resolve very fine and detailed features of the *** examined specimens from the skin of the amphibians Salamandra salamandra Linnaeus,1758,Lyciasalamandra luschani basoglui Baran&Atatür,1980 and Mesotriton alpestris Laurenti,1768,and from the surface of pollen grains of the plant species Cyclamen graecum Link,1835 and Cistus salviifolius Linnaeus,1753,which exhibit certain interesting features,imaged at the nanoscale *** is likely that the relief influences the attributes of the interfaces between the tissues and the *** found that the microsculpture increases in size the surface of the examined tissues and this might be particularly important for their performance in the *** of amphibians’skin may affect water regulation,dehydration and rehydration,and cutaneous gas *** grain relief might affect the firmness of the contact between pollen surface and water *** resolution imaging of the external relief showed that roughening might induce wetting and influence the water status of the *** addition,roughness affects the radius of water droplets retained in between the projections of the external *** of the tissues was highly correlated with their vertical distance,whereas surface distances were highly correlated with horizontal *** enabling a more detailed characterization of the external sculptures,through sophisticated techniques,a more comprehensive examination of the samples indicates similarities among different living tissues,originated from different kingdoms,which can be attributed to environmental conditions and physiological circumstances.

摘要：In present study,four new dammarane-type triterpenoids,namely caffruones A–D(1–4),were isolated from the cherries of Coffea *** structures were elucidated by extensive spectroscopic analysis including 1D,2D NMR(HSQC,HMBC,^(1)H–^(1)H COSY,and ROESY),HRMS and IR *** is the first time that tetracyclic triterpenes have been reported in genus Coffea.

摘要：Four eburicane-type triterpenoids with malonyl modifications,namely irpexoates A-D(1-4),were isolated from the fruiting bodies of the medicinal fungus Irpex *** structures of the new compounds were established by extensive spectroscopic methods,including 1D and 2D NMR,HRESIMS spectroscopic *** B(2)displayed weak cytotoxicity against four human cancer cell lines(A-549,SMMC-7721,MCF-7,SW480)with IC50 values varying from 22.9 to 34.0 pM,and irpexoate D(4)showed weak cytotoxicity against the human cancer cell line SW480 with an IC50 value of 35.2μM.

摘要：Burning crop residues and excessive use of chemical fertilizers results in an enormous waste of bio- logical resources, which further weakens the potential capacity of the agro-ecosystem as a carbon sink. To explore the potential of farmlands acting as a carbon sink without yield losses, we conducted an experiment on a temperate eco-farm in eastern rural China. Crop residues were applied to cattle feed, and the composted cattle manure was returned to cropland with a winter wheat and maize rotation. Four different proportions of fertilizers were designed： 100 % cattle manure, 100 % mineral nitrogen, 75 % cattle manure plus 25 % mineral nitrogen, and 50 % cattle manure plus 50 % mineral nitrogen. Crop yield and greenhouse gas （GHG） emissions were carefully calculated according to the Intergovernmental Panel on Climate Change （IPCC） Guidelines for National Green- house Gas Inventories 2006. Our results showed that replacing chemical fertilizer with organic manure signifi- cantly decreased the emission of GHGs. Yields of wheat and corn also increased as the soil fertility was improved by the application of cattle manure. Totally replacing chemical fertilizer with organic manure decreased GHG emissions, which reversed the agriculture ecosystem from a carbon source （＋2.7 t CO_2-eq. hm-2 year-1） to a carbon sink （-8.8 t CO_2-eq. hm^-2 year^-1）. Our findings provide useful insights for improving agricultural ecosystems under global change scenarios.

摘要：2017年中国植物科学继续保持高速发展态势,重大成果频出,具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈,如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中,有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外,值得一提的是,长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果"水稻高产优质性状形成的分子机理及品种设计"荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理,旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态,与广大读者共同分享我国科学家所取得的辉煌成就。