[sciencedirect意思]科研进展一周快讯(2015年11月5日) Weekly summary of progress of plant science

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1.Plos Genetics:发现水稻抗旱耐盐转录调控通路新成员

TitleDCA1 Acts as a Transcriptional Co-activator of DST and Contributes toDrought and Salt Tolerance in RicePLoS Genetics, October 26, 2015

:发现水稻抗旱耐盐转录调控通路新成员

随着水资源短缺、土壤盐碱化的趋势日益加剧,干旱和盐碱已成为影响农作物生产的两大主要危害因子,威胁粮食安全。为了解决这一农业难题,长期以来国内外植物学家致力于开展作物抗逆性状的分子调控机理研究,为作物抗逆分子育种改良提供理论基础。来自中科院植生所林鸿宣研究组在前期鉴定得到一个控制水稻抗旱耐盐的重要转录因子DST (Drought and SaltTolerance)的基础上,通过酵母双杂交技术寻找参与DST抗逆机制的新成员,发现了DST Co-Activator 1(DCA1),其是一个功能未知的CHY锌指蛋白。当过量表达DCA1时使转基因水稻植株对盐、旱胁迫变得更敏感,而该基因的突变体dca1却明显增强水稻对盐、旱胁迫的耐受性,表明DCA1是一个抗逆负调控因子。通过进一步研究证明DCA1对DST的转录活性具有促进作用,并且过量表达DCA1可以增加气孔开度而dca1可以降低气孔开度,这种调控气孔的开度是通过调节H2O2的量而实现的,DCA1与DST可能形成异源四聚体行使调节H2O2的功能。这些研究结果为作物抗逆机理的深入研究提供新线索,并且为作物抗逆性(抗旱和耐盐)的分子育种提供有价值的基因专利。

Abstract: Natural disasters, including drought and saltstress, seriously threaten food security. In previous work we cloned a key zincfinger transcription factor gene, Drought and Salt Tolerance(DST), anegative regulator of drought and salt tolerance that controls stomatalaperture in rice. However, the exact mechanism by which DST regulates theexpression of target genes remains unknown. In the present study, wedemonstrated that DST Co-activator 1 (DCA1), a previously unknown CHY zincfinger protein, acts as an interacting co-activator of DST. DST was found tophysically interact with itself and to form a heterologous tetramer with DCA1.This transcriptional complex appears to regulate the expression of peroxidase24 precursor (Prx 24), a gene encodingan H

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scavengerthat is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought andsalt tolerance in rice, and overexpression of DCA1 increased sensitivity to stresstreatment. These phenotypes were mainly influenced by DCA1 and negativelyregulated stomatal closure through the direct modulation of genes associatedwith H

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homeostasis.Our findings establish a framework for plant drought and salt stress tolerancethrough the DCA1-DST-Prx24 pathway. Moreover, due to theevolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathwayhas the potential to improve tolerance to abiotic stress in other importantcrop species.

2.揭示微丝调节水稻形态发育新机制

TitleVLN2 Regulates Plant Architectureby Affecting Microfilament Dynamics and Polar Auxin Transport in Rice

ThePlant Cell, October 23, 2015

揭示微丝调节水稻形态发育新机制
微丝是细胞骨架的一种,它通过动态变化来调节众多细胞学过程。目前的研究表明,微丝参与到细胞减数分裂、有丝分裂、囊泡和细胞器运动和细胞生长。尽管最近的研究表明,微丝可以影响植物形态发育,但是其中的机制尚不清楚。来自农科院作物科学研究所的万建民团队微丝结合蛋白Villin2(VLN2)通过调节微丝的动态变化,影响细胞膨大、生长素极性运输以及水稻的生长发育。该课题组通过体内和体外实验证明了VLN2具有剪切、成束和封盖微丝的功能。此外,该课题组从vln2突变体对重力响应超敏感入手,发现了突变体根中生长素输出载体PIN2循环异常、生长素不对称分布等表型。这表明VLN2可能通过调节微丝影响PIN循环,继而影响了生长素极性运输和分布,再影响到细胞膨大和器官异常。该研究为进一步阐明微丝与植物发育的机制研究奠定了基础,对水稻形态改良提供理论支持。

Abstract:As a fundamental and dynamic cytoskeletonnetwork, microfilaments (MFs) areregulated by diverse actin binding proteins (ABPs). Villins are one type ofABPs belonging to the villin/gelsolin superfamily, and their function is poorlyunderstood in monocotyledonous plants. Here, we report the isolation andcharacterization of a rice (Oryzasativa) mutant defective in VILLIN2 (VLN2),which exhibits malformed organs, including twisted roots and shoots at theseedling stage. Cellular examination revealed that the twisted phenotype of the vln2mutantis mainly caused by asymmetrical expansion of cells on the opposite sides of anorgan. VLN2 is preferentially expressed in growingtissues, consistent with a role in regulating cell expansion in developingorgans. Biochemically, VLN2 exhibits conserved actin filament bundling,severing and capping activities in vitro, with bundling and stabilizingactivity being confirmed in vivo. In line with these findings, the vln2 mutant plants exhibit a more dynamicactin cytoskeleton network than the wild type. We show that vln2 mutant plants exhibit a hypersensitivegravitropic response, faster recycling of PIN2 (an auxin efflux carrier), andaltered auxin distribution. Together, our results demonstrate that VLN2 plays an important role in regulatingplant architecture by modulating MFdynamics,recycling of PIN2, and polar auxin transport.

3.Science: 控制植物根系发育的新转录因子

TitleTranscriptional control of tissue formation throughout rootdevelopment

ScienceOctober 23,2015

控制植物根系发育的新转录因子

当生长的植物根推动自己通过土壤的时候,新的细胞必须呈现适当的身份和位置,以形成不同的组织层次,给予植物根的根系结构,保护它不受外界环境的伤害,并确保它可以将运输的物质正确地送到植物的其他部位。以前的研究表明SHORT-ROOT和SCARECROW的两个因子,共同启动了这个进程,控制着这些结构形成过程。最近,来自他们也已经找到了这个过程需要的其他关键调控因子BIRDs。该转录因子和SCARECROW基因共同调控干细胞分裂、根系细胞形态建成。研究表明,BIRDs可能帮助corral SHORT-ROOT进入发育的根的正确层面,以发挥其作用。当BIRDs缺失时,细胞无法打开对基本组织身份非常重要的基因。

Abstract: Tissue patterns are dynamically maintained. Continuousformation of plant tissues during postembryonic growth requires asymmetricdivisions and the specification of cell lineages. We show that the BIRDs andSCARECROW regulate lineage identity, positional signals, patterning, andformative divisions throughout Arabidopsis root growth. These transcriptionfactors are postembryonic determinants of the ground tissue stem cells andtheir lineage. Upon further activation by the positional signal SHORT-ROOT (amobile transcription factor), they direct asymmetric cell divisions andpatterning of cell types. The BIRDs and SCARECROW with SHORT-ROOT organizetissue patterns at all formative steps during growth, ensuring developmentalplasticity.

4.Cell:EIN2介导对乙烯信号翻译水平的调控

TitleEIN2-Directed Translational Regulation of Ethylene Signaling inArabidopsisCell, October 22, 2015

:EIN2介导对乙烯信号翻译水平的调控

乙烯(Ethylene)是植物响应各种内部及环境刺激生成的一种气体激素,其能够触发广泛的生理和形态学反应。在过去的几十年里,研究人员通过应用一些分子和遗传学方法,确定了一条相对线性的乙烯信号通路。在拟南芥中,乙烯信号进入细胞后,位于内质网上的一组乙烯受体(ETR1、ETR2、ERS1、ERS2和EIN4)能够与乙烯结合,使CTR1失活,并将信号传递给EIN2,在传递到位于细胞核内的EIN3/EIL和ERF,最终调控乙烯相关蛋白得而表达。最近,来自北京大学的郭红卫研究员发现了EIN2控制乙烯信号传导的另一种机制:EIN2促成了对EBF1 and EBF2 mRNA翻译水平上的抑制。他们证实是由EBF1/2的3′ UTRs介导了EIN2对它们的翻译水平抑制,并鉴别出多个多聚鸟苷酸(PolyU)模体是3′ UTRs的功能性顺式元件。此外,研究人员还证实乙烯可诱导EIN2与3′ UTRs结合,通过与多个胞质加工小体(cytoplasmic processing bodies, P-小体) 因子包括EIN5和PABs互作,EIN2让EBF1/2 mRNA定位到了P-小体中由此抑制EBF1/2翻译。新研究阐明了作为乙烯信号转导关键步骤的翻译调控,揭示出了在植物中mRNA 3′ UTR充当“信号转导子”感知并传送细胞信号的一个重要机制。

Abstract: Ethylene is a gaseous phytohormone thatplays vital roles in plant growth and development. Previous studies uncoveredEIN2 as an essential signal transducer linking ethylene perception on ER totranscriptional regulation in the nucleus through a “cleave and shuttle” model.In this study, we report another mechanism of EIN2-mediated ethylene signaling,whereby EIN2 imposes the translational repression of EBF1 and EBF2 mRNA. Wefind that the EBF1/2 3′ UTRs mediate EIN2-directed translational repression andidentify multiple poly-uridylates (PolyU) motifs as functional cis elements of3′ UTRs. Furthermore, we demonstrate that ethylene induces EIN2 to associatewith 3′ UTRs and target EBF1/2 mRNA to cytoplasmic processing-body (P-body)through interacting with multiple P-body factors, including EIN5 and PABs. Ourstudy illustrates translational regulation as a key step in ethylene signalingand presents mRNA 3′ UTR functioning as a “signal transducer” to sense andrelay cellular signaling in plants.

5.Cell揭示RNA甲基化的重要功能

Title5 UTR m

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A Promotes Cap-Independent Translation
Cell, October 29, 2015

揭示RNA甲基化的重要功能
近几年来,科学家们发现了一种可逆性的RNA甲基化——N6-methyladenosine(m6A)。m6A是真核生物mRNA上最常见的一种转录后修饰,介导了超过80%的RNA甲基化。m6A修饰非常普遍,出现频率大约是3-5个残基/mRNA。现在研究者们正在逐渐揭开mRNA甲基化的神秘面纱。目前,来自康奈尔大学的Samie R. Jaffrey领导研究团队研究表明,mRNA的5’ UTRm6A能够直接结合真核起始因子3(eIF3),不需要帽子结合因子eIF4E就能招募43S复合体并起始翻译。抑制这种RNA甲基化会选择性减少这类mRNA的翻译。研究人员还发现,5’ UTR出现m6A可以增加mRNA的翻译。举例来说,热激会提高Hsp70mRNA上的m6A水平,使其以不依赖帽子的方式翻译。研究指出,不同的细胞压力诱导m6A在整个转录组上重新分配,导致具有5’ UTRm6A的mRNA增多。由此可见,5’ UTRm6A能够绕过5’ 帽子结合蛋白,在压力条件下促进蛋白质翻译。

Abstract: Proteintranslation typically begins with the recruitment of the 43S ribosomal complexto the 5′ cap of mRNAs by a cap-binding complex. However, some transcriptsare translated in a cap-independent manner through poorly understoodmechanisms. Here, we show that mRNAs containing N

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-methyladenosine(m

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A) in their 5′ UTR can be translated in a cap-independentmanner. A single 5′ UTR m

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A directly binds eukaryotic initiation factor 3 (eIF3), whichis sufficient to recruit the 43S complex to initiate translation in the absenceof the cap-binding factor eIF4E. Inhibition of adenosine methylationselectively reduces translation of mRNAs containing 5′UTR m

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A.Additionally, increased m

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A levels in the Hsp70 mRNA regulate its cap-independenttranslation following heat shock. Notably, we find that diverse cellularstresses induce a transcriptome-wide redistribution of m

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A, resultingin increased numbers of mRNAs with 5′ UTR m

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A. These datashow that 5′ UTR m

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A bypasses 5′ cap-binding proteins to promote translationunder stresses.

6.无需克隆的CRISPR新技术

TitleCloning-free CRISPRStem Cell Reports, October29, 2015

无需克隆的CRISPR新技术
来自荷兰Hubrecht研究所和乌特勒支医学中心(UMCUtrecht)、麻省理工学院的研究人员称,他们开发出了一种自身克隆CRISPR/Cas9(scCRISPR)技术,可以绕开基因编辑过程中所有的克隆步骤,在数小时内完成CRISPR/Cas9介导基因突变及位点特异性转基因敲入。这种scCRISPR技术无需为每个靶位点克隆出一条位点特异性的sgRNA或基因敲入同源性载体,可在数小时内完成CRISPR/Cas9介导基因组突变或位点特异性的转基因敲入。研究人员称他们将一种自我切割的回文结构sgRNA质粒,和一条编码所需位点特异性sgRNA的双链DNA短序列导入到靶细胞中,使得它们能够通过同源重组生成位点特异性sgRNA质粒。每个靶位点只需2小时准备时间,相比于基于质粒构建sgRNA,scCRISPR可以低近6倍的成本有效地实现基因敲除(突变率达到88%)。随后,研究人员在小鼠和人类胚胎干细胞(ESCs)及HEK293T细胞中证实了它们的基因组编辑效率。

Abstract: We present self-cloning CRISPR/Cas9 (scCRISPR), a technologythat allows for CRISPR/Cas9-mediated genomic mutation and site-specific knockintransgene creation within several hours by circumventing the need to clone asite-specific single-guide RNA (sgRNA) or knockin homology construct for eachtarget locus. We introduce a self-cleaving palindromic sgRNA plasmid and ashort double-stranded DNA sequence encoding the desired locus-specific sgRNAinto target cells, allowing them to produce a locus-specific sgRNA plasmidthrough homologous recombination. scCRISPR enables efficient generation of geneknockouts (∼88% mutation rate) atapproximately one-sixth the cost of plasmid-based sgRNA construction with only2 hr of preparation for each targeted site. Additionally, we demonstrateefficient site-specific knockin of GFP transgenes without any plasmid cloningor genome-integrated selection cassette in mouse and human embryonic stem cells(2%–4% knockin rate) through PCR-based addition of short homology arms.scCRISPR substantially lowers the bar on mouse and human transgenesis.

7.简易高效多基因编辑系统

TitleA Simple CRISPR/Cas9 System for Multiplex Genome Editing in Rice

Journalof Genetics and Genomics, October 24, 2015

简易高效多基因编辑系统
在水稻功能基因组研究过程中,通常需要创制多基因突变体。目前,水稻多突变体的获得只能依赖于单突变体间的多次遗传杂交以及后代群体筛选的方法,整个过程不仅耗时而且费力。水稻所王克剑和扬州大学科研团队基于CRISPR-Cas9技术设计了多基因编辑系统。该系统只包含两个质粒,利用同尾酶的特性,通过传统的酶切连接方式,实现多个gRNA元件的快速组装。该系统理论上可以实现无限个gRNA的组装。在构建好载体之后,仅需要一次转基因,在转基因当代就可快速获得需要的多突变体。对得到的转基因水稻进行靶序列分析,发现同时编辑3个基因的效率可达60%左右。此外,统计分析还发现,不同基因位点倾向于同时发生突变,表明共突变发生频率可能与Cas9本身的活性相关。

Abstract: In this study, we developed a simpleisocaudamers-based system to generate multiple mutations in rice based on theCRISPR-Cas9 genome editing technology. The high co-mutation rate observed inthe transgenic plants indicates that our system functions with high-efficiency.The establishment of our CRISPR-Cas9 vector system makes it straightforward andconvenient to generate plants with multiple gene mutations using conventionalstrategy. Thus, the use of this system will facilitate investigations into therelationships among multiple genes, and also accelerate the rate of cropbreeding in the future.

相关问答

问:sciencedirect中的open access是什么意思

答:open access
开放获取;开放存取;开放取用
例句
1.Open Access begins with a licence declaration by the author or copyrightholder.
开放获取始于作者或版权所有人的许可声明。
2.Open access is a free conception and publishing mechanism for the sharing ofscholarly information resources.
开放存取是一种学术信息共享的自由理念和出版机制。


问:sciencedirect是什么

答:一个网上数据库。
Elsevier Science的1,263种全文电子期刊的学科分类如下:
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求采纳哦!谢谢!O(∩_∩)O


问:sciencedirect是什么

答:Elsevier(sciencedirect)是荷兰一家全球著名的学术期刊出版商,每年出版大量的学术图书和期刊,大部分期刊被SCI、SSCI、EI收录,是世界上公认的高品位学术期刊。近几年该公司将其出版的2,500多种期刊和11,000图书全部数字化,即ScienceDirect全文数据库,并通过网络提供服务。该数据库涉及众多学科:计算机科学、工程技术、能源科学、环境科学、材料科学、数学、物理、化学、天文学、医学、生命科学、商业、及经济管理、社会科学等。国内11所学术图书馆于2000年首批联合订购SDOS数据库中1998年以来的全文期刊。


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