Cloning of XET gene from Anthocephalus chinensis and its plant expression vector construction

A full-length cDNA sequence of xyloglucan endotransglycosylase gene （XET）, abundantly expressed in the cambium of Anthocephalus chinensis was cloned by conserved PCR, rapid-amplification of cDNA ends and by chromosome walking. Analytical results of the DNA sequence show that a 912 bp complete open reading frame （ORF） encoded a 303-amino acid protein was in the 1205 bp full cDNA sequence. The deduced amino acid sequence of AcXET, which contained the conserved specific EIDFE catalytic site sequence to XETs was homologous to the other known XET proteins. In order to study the gene function of AcXET and obtain transgenic plants, a plant expression vector pBIAcXET was constructed by recombinating the AcXET fragment from the cloning vector pMD19AcXET and the binary vector pBI121 between the XbaI and SmaI sites. The fragment ofAcXET gene was inserted between the CaMV 35S promotor and the coding region of the GUS gene in pBI121. The identification results show that the plant expression binary vector pBIAcXET was constructed successfully. These results lay the foundation for studying the molecular mechanism ofAcXET gene during wood formation.

A Nimble Cloning-compatible vector system for high-throughput gene functional analysis in plants

Plant expression vectors are essential tools for gene functional analysis and molecular plant breeding.The gene of interest is transferred to the vector by molecular cloning technology.Nimble Cloning is a newly developed molecular cloning method with the advantages of simplicity,efficiency,and standardization.In this study,we developed a"pNC"vector system that contains 55 Nimble Cloning-compatible vectors for functional analysis of genes in plants.These vectors contain the NC frame flanked by unique adapters for one-step and standardized Nimble Cloning.We demonstrate that the pNC vectors are convenient and effective for the functional analysis of plant genes,including the study of gene ectopic expression,protein subcellular localization,protein-protein interaction,gene silencing(RNAi),virus-induced gene silencing,promoter activity,and CRISPR-Cas9-mediated genome editing.The"pNC"vector system represents a high-throughput toolkit that can facilitate the large-scale analysis of plant functional genomics.

Cloning and Characterization of WOX4 Gene from Vitis vinifera L. Involved in Stem Cell Regulation

Wuschel-related homeobox （WOX） genes play essential, specific, and sometimes redundant roles in plant embryo development, shoot and root meristem maintenance, and plant development. Though much information was quickly gained with members of the WOX gene family of Arabidopsis, monocotyledonous crops, and gymnospermous conifers, little is known about perennial woody plants. In this study, we isolated the first WOXgene family member from grape （Vitis vinifera L. cv. Cabernet Sauvignon）, and named it VvWOX4 based on its characteristic domains and phylogenetic analysis. The identity of VvWOX4 was validated by MALDI-TOF MS and Western blot with polyclonal antibody against Arabidopsis thaliana Wuschel. Functional analysis showed that VvWOX4 markedly increased shoot primordia structures when overexpressed under CaMV 35S promoter in tobacco. A different expression pattern was found for VvVOX4 compared with AtWUCHEL and its expression was detected in unique organs of grapevines. Besides the expression in the vegetative shoot apical meristem （SAM） of grape shoot tips, VvWOX4 is expressed in dormant winter buds, inflorescence, young leaves, and tendril tips, but not in root tips. In young leaves, the expression of VvWOX4 is strongly upregulated by wounding, and also by plant growth regulators such as 2 mg L-1 2,4-D, 1 mg L-1 NAA and 1 mg L-1 BAP treatments, while downregulation was monitored by 1 mg L^-1 IBA treatment, and there was no response to 0.5 mg L-1 GA3 treatment. Together, our results revealed the first member of grape WOX gene family and indicated different roles and regulation of VvWOX4 in the perennial woody crop grapevine.

Rice bicoid-related cDNA sequence and its expression during early embryogenesis

Bicoid is one of the important Drosophila maternal genes involved in the control of embryo polarity and larvae segmentation. To clone and characterize the rice bicoid-related genes, one cDNA clone, Rb24 (EMBL accession number: AJ2771380), was isolated by screening of rice unmature seed cDNA library. Sequence analysis indicates that Rb24 contains a putative amino acid sequence, which is homologous to unique 8 amino acids sequence within Drosophila bicoid homeodomain (50% identity, 75% similarity) and involves a lys-9 in putative helix 3. Northern blot analysis of rice RNA has shown that this sequence is expressed in a tissue-specific manner. The transcript was detected strongly in young panicles, but less in young leaves and roots. This results are further confirmed with paraffin section in situ hybridization. The signal is intensive in rice globular embryo and located at the apical tip of the embryo, then, along with the development of embryo, the signal is getting reduced and transfers into both sides of embryo. The existence of bicoid-related sequence in rice embryo and the similarity of polar distribution of bicoid and Rb24 mRNA in early embryo development may implicates a conserved maternal regulation mechanism of body axis presents in Drosophila and in rice.

Development and mapping of SSR markers linked to resistance-gene homologue clusters in common bean

Common bean is an important but often a disease-susceptible legume crop of temperate,subtropical and tropical regions worldwide. The crop is affected by bacterial, fungal and viral pathogens. The strategy of resistance-gene homologue(RGH) cloning has proven to be an efficient tool for identifying markers and R(resistance) genes associated with resistances to diseases. Microsatellite or SSR markers can be identified by physical association with RGH clones on large-insert DNA clones such as bacterial artificial chromosomes(BACs). Our objectives in this work were to identify RGH-SSR in a BAC library from the Andean genotype G19833 and to test and map any polymorphic markers to identify associations with known positions of disease resistance genes. We developed a set of specific probes designed for clades of common bean RGH genes and then identified positive BAC clones and developed microsatellites from BACs having SSR loci in their end sequences. A total of 629 new RGH-SSRs were identified and named BMr(bean microsatellite RGH-associated markers). A subset of these markers was screened for detecting polymorphism in the genetic mapping population DOR364 × G19833. A genetic map was constructed with a total of 264 markers,among which were 80 RGH loci anchored to single-copy RFLP and SSR markers. Clusters of RGH-SSRs were observed on most of the linkage groups of common bean and in positions associated with R-genes and QTL. The use of these new markers to select for disease resistance is discussed.

Cloning and Expression of Two MYB Transcription Factors in Tea Plant(Camellia sinensis)

MYB transcription factors represent a family of genes that include the conserved MYB DNA-binding domain,and they are widely involved in the regulation of plant development and secondary metabolism.In this study,Part of sequences of two MYB transcription factors was determined through the cDNA microarray hybridization and selection of cDNA library derived from tender shoots.The full-length cDNAs of the genes were obtained with RT-PCR and RACE,and they were 1 132 bp and 1 020 bp,named as CsMYB1 and CsMYB2 (GenBank accession No.HQ660373 and HQ660374), and contained ORFs of 879 bp and 675 bp encoding 292 and 224 amino acids,respectively.Sequences analysis showed that the deduced protein molecular weight of the two genes were 32.9 ku and 25.4 ku, and the proteins contained two conserved MYB domains near the N-terminus and a conserved C1 motif near the R3 domains.The deduced amino acid sequence of CsMYB1 and CsMYB2 from tea plant showed high identity with that of other plants,for instance CsMYB1 shared 57%homology with MYB1 of Gossypium hirsutum and CsMYB2 shared 75% homology with MYBC2 of Vitis vinifera.The result of real time-PCR analysis showed the two genes were expressed constitutively in all tissues with different expression levels,e.g.the relative expression level of CsMYB2 in leaf was hundred times higher than that in root.Additionally,shading enhanced CsMYB1 expression,while the treatment did not alter the expression level of CsMYB2.

金黄色葡萄球菌CHIPS基因克隆及原核表达

趋化抑制蛋白(Chemotaxis Inhibitory Protein ofStaphylococcus aureus,CHIPS)是由金黄色葡萄球菌分泌到菌体外的一种蛋白。在感染早期,它能特异性地与中性粒细胞和单核细胞上的C5a受体(C5aR)和fMLP受体(FPR)结合,从而阻止中性粒细胞和单核细胞对C5a和fMLP的结合作用,导致对病原吞噬作用的延迟。人们可以利用CHIPS对C5a-C5aR的阻止作用来研制治疗由C5a诱发的炎症性疾病的药物。将CHIPS作为免疫原防治疾病也将成为新的研究课题。实验成功构建了CHIPS蛋白的原核表达系统,为CHIPS免疫原性研究及蛋白的其他功能研究奠定了基础。

大白菜BrCYP83B1基因的克隆及表达分析

【目的】细胞色素P450家族是十字花科植物硫苷合成重要的酶系,其中CYP83亚家族主要参与核心结构的合成,旨在探究大白菜(Brassica rapa ssp.pekinensis)CYP83B1基因的功能。【方法】利用RT-PCR技术克隆BrCYP83B1基因,通过生物信息学软件分析其编码蛋白理化性质、同源性及启动子顺式作用元件,利用RT-qPCR技术分析BrCYP83B1的表达模式,并构建其植物超表达载体。【结果】BrCYP83B1 cDNA序列全长为1500 bp,编码499个氨基酸,编码蛋白属于细胞色素P450超家族,主要定位于细胞质,二级结构主要由α-螺旋和无规则卷曲构成,与甘蓝型油菜、青花菜的CYP83B1蛋白具有较高的同源性。启动子分析表明,该基因启动子区域包含水杨酸、脱落酸及茉莉酸甲酯等激素响应的顺式作用元件,说明BrCYP83B1基因表达可能受激素调控。RT-qPCR分析结果表明,BrCYP83B1基因在大白菜的根、茎、叶、花和果中均有表达,且以叶中的表达量最高;茉莉酸甲酯够显著促进该基因的表达,而水杨酸处理对其表达具有一定的抑制作用,脱落酸处理下基因先上调后又下调。【结论】BrCYP83B1可能参与大白菜对激素的响应调控。

腰果AoCDPK26基因的克隆、亚细胞定位及表达特性分析

CDPK基因家族在植物非生物胁迫中发挥着重要作用,为了探究腰果Anacardium occidentale L.中AoCDPK26基因的功能和表达特性,以腰果叶片为试材,通过RT-PCR扩增技术,获得AoCDPK26基因序列,利用生物信息学分析方法对其理化性质、氨基酸序列、蛋白质结构进行初步分析预测,利用RT-qPCR技术测定其在腰果不同组织部位、低温和不同植物生长调节剂处理后的表达特性。在烟草中构建pEGAD-35S::AoCDPK26-GFP重组载体对AoCDPK26基因进行亚细胞定位。结果表明,腰果AoCDPK26基因编码区序列含有1692 bp的开放阅读框1个,编码氨基酸564个,系统进化树分析发现该序列与开心果具有较高的亲缘关系。AoCDPK26基因在腰果的根、茎、叶、花、果梨和果仁中均有表达,其中叶片中的表达量最高。在低温胁迫下,处理5 d后叶片AoCDPK26基因的表达量达到最高,是对照表达量的38倍;用茉莉酸甲酯(MeJA)处理腰果幼苗24 h后,叶片AoCDPK26基因表达量增幅最大。在烟草组织亚细胞定位发现,AoCDPK26定位于细胞膜和细胞核中。说明腰果AoCDPK26基因可能参与低温胁迫和内源激素响应的调控。

CONSTRUCTION OF Sesbania rostrata COSMID GENOMIC LIBRARY AND MOLECULAR CLONING OF LEGHEMOGLOBIN GENE

Using plant mini-Ti cosmid pEND4K, the cosmid genomic library of Sesbania rostratawas constructed. Sizes of plant DNA inserts in clones were 25- 33 kb. The restrictionmapping showed that different recombinant involved various types of plant DNA insert. 4clones containing leghemoglobin gene sequence of S. rostrata were obtained by in situ hy-bridization of colonies. The cloning of leghemoglobin gene sequence has been confirmedby plasmid DNA dot hybridization and Southern blot hybridization.

基因芯片技术在植物基因克隆中的应用研究进展

基因芯片是以预先设计的方式将大量的生物讯息密码(寡核苷酸、cDNA、基因组DNA等)固定在玻片、硅片等固相载体上组成的密集分子阵列。基因芯片技术本质是生物信号的平行分析,它利用核酸分子杂交原理,通过荧光标记技术检测杂交亲和与否,再经过计算机分析处理可迅速获得所需信息。由于其具有高通量、微型化、连续化、自动化、快速和准确等特点,已引起国际国内广泛的关注和重视,在许多领域得到了广泛的应用。本文简述了基因芯片的概念,技术特点及主要分类,着重对其在基因表达水平检测,基因突变和多态性的分析,基因组DNA分析,后基因组学研究以及转基因农作物检测等方面进行阐述,并说明其存在的问题及展望。

电子克隆技术及其在植物基因工程中的应用

电子克隆是随着基因组计划和EST计划的实施而发展起来的,是利用生物信息学手段进行基因克隆的新方法。它具有投入低、速度快、技术要求低和针对性强等优点。因此,电子克隆技术必将成为植物基因工程中获得新基因的重要手段。阐述了电子克隆应用所依据的数据库与生物信息资源,介绍了利用电子克隆获得功能基因的方法,及其在植物基因工程中的应用现状与前景。

基因芯片技术及其在植物病害研究中的应用

基因芯片即DNA系列 (DNAmicroarray) ,主要包括cDNA微列阵与寡聚核苷酸微列阵两种类型。基因芯片技术即DNA微列阵技术是近年来在生命科学技术领域中 ,迅速发展起来的一项探索基因组功能的高新技术。本文简要综述了基因芯片、表达谱芯片技术的概念、原理、分类和制作方法 。

植物细胞色素P450酶系的研究进展及其与外来物质的关系

植物细胞色素P45 0是分子量为 40— 60KD、结构类似的一类血红素 硫铁蛋白。它以可溶性和膜结合两种形态存在于植物细胞内 ,可催化多种化学反应 ,在防御植物免受有害物质侵害方面具有重要作用。目前已克隆 90多个植物细胞色素P45 0基因。本文概述了植物P45 0基因表达调控与环境、发育、组织特异性关系的研究进展。认为植物P45

植物基因启动子的克隆及其功能研究进展

启动子在植物基因表达调控过程中起着重要作用。对于植物基因启动子的克隆及其功能研究有助于了解信号传递途径和基因表达调控模式,为植物转基因工程研究提供理论依据。本文综述了植物基因启动子的基本结构、类型、克隆方法及功能研究进展,着重介绍了广泛应用于转基因工程的诱导型启动子及启动子功能分析,展望了今后植物启动子的研究方向。

细胞色素P450基因及其在植物改良中的应用

细胞色素P450是一类含血红素的氧化还原酶类,它参与多种生化反应,在防御生物免受病虫害及逆境胁迫等方面具有重要作用。生物基因组序列分析表明,它是一个基因超家族。许多细胞色素P450基因已被鉴定和克隆,并应用于植物遗传改良;在转基因培育多抗性植物、创造植物雄性不育系,提高植物降解化学农药残留等污染物的能力和有效生产具有药用价值的化合物等方面已取得可喜进展,显示出广阔的应用前景。

小麦条锈病和白粉病成株抗性研究进展与展望

利用成株抗性是小麦抗病育种的重要方向,本文综述了小麦条锈病和白粉病成株抗性鉴定方法、基因定位和克隆及其在育种中的应用。将报道的72个条锈病成株抗性数量性状遗传位点(quantitative trait loci,QTL)和82个白粉病成株抗性QTL整合到一张连锁图谱上,控制2种病害的基因簇(≥5个QTL)有8个,其中位于7DS的Yr18/Lr34/Pm38和1BS的Yr29/Lr46/Pm39对条锈病、叶锈病和白粉病均表现成株抗性,位于4DL的Yr46/Lr67位点可能也对白粉病表现成株抗性,Yr18/Lr34/Pm38和Yr36已被克隆,Yr29/Lr46/Pm39的克隆已取得良好进展,为培育兼抗和成株抗性相结合的品种提供了可用基因。总结了成株抗性在中国小麦育种中的应用现状,并用实例证实了培育成株抗性品种的可行性,建议对兼抗条锈病和白粉病成株抗性的咸农4号和小偃6号等进行遗传分析,育种工作者和品种审定部门需要转变观念,将成株抗性利用作为国内条锈病和白粉病抗性育种的重要内容。

茶树冷胁迫诱导抗寒基因CBF的克隆与表达分析

利用cDNA-AFLP技术进行了茶树低温胁迫处理的基因表达差异分析,获得低温诱导后特异表达的差异片段TDF11(transcript derived fragment,TDF)。经BLAST比对发现该片段与白菜、拟南芥、烟草的抗寒基因CBF(C-repeat binding factor)分别有94%、84%、81%的同源性。通过3’/5’RACE的方法获得该片段cDNA全长序列(GenBank,登录号EU857638)。所得序列全长981bp,其开放阅读框编码275个氨基酸。该基因与白菜、烟草、拟南芥中的CBF基因编码的氨基酸序列分别有74%、57%、57%的同源性。用RT-PCR的方法对其在低温处理过程中的表达进行分析,结果表明,茶树CBF基因在低温诱导4h开始表达,在8h左右表达量最高,然后开始下降,但仍维持在一个较高的水平。结果提示CBF基因可能在茶树抗寒分子机制的形成过程中发挥重要的作用。

茶树CsNCED2基因的克隆和表达分析

该研究以铁观音茶树品种叶片为材料,通过RT-PCR技术,克隆了茶树脱落酸(ABA)合成途径关键限速酶——9-顺式环氧类胡萝卜素裂解双加氧酶(9-cis-epoxycarotenoid dioxygenase,NCED)基因的全长cDNA序列。该基因cDNA全长1 931bp,包含1 821bp完整开放阅读框,共编码606个氨基酸残基。NCBI同源分析结果表明,与葡萄VvNCED2相似性最高(78%),命名为CsNCED2(NCBI登录号:MF765770)。氨基酸序列分析显示,其具有NCED家族的FLNO2258保守结构域,以及MIAHPKxDP和HDFAITE保守结构域序列;在保守区存在4个Fe2+活性组氨酸结合位点,N-端含有叶绿体转运肽。实时荧光定量PCR分析表明,CsNCED2基因在铁观音叶、茎和花中表达量较高;白茶萎凋和乌龙茶做青均可以诱导CsNCED2基因显著上调表达;除干旱胁迫抑制CsNCED2表达外,ABA和低温胁迫均能够诱导CsNCED2基因显著上调表达。表明CsNCED2基因在茶树ABA合成代谢以及胁迫响应中发挥重要作用。

新基因TSBAG的生物信息学分析及其在小鼠睾丸组织中的表达

目的：筛选与精子发生相关的睾丸特异性新基因,并探讨其在精子发生过程中所起的作用。方法：将不同发育阶段的小鼠睾丸组织cDNA探针与Affymetrix全基因组芯片进行杂交,通过杂交信号的比较,筛选出差异表达的基因。用生物信息学软件对该基因进行生物信息学分析。RT-PCR分析该基因在小鼠不同发育阶段睾丸、小鼠不同组织中的表达。结果：通过4日龄、9日龄、18日龄、35日龄、54日龄和6月龄小鼠睾丸的芯片信号比较筛选出一个差异表达功能未知的新基因(GenBank登录号：BC049770),全长891 bp,含有702 bp的完整ORF,编码一个233个氨基酸、相对分子量为26．938 kD的蛋白质,我们将其命名为TSBAG(testis-specific BAG-like protein)。亚细胞定位预测显示,TSBAG基因可能在细胞核中表达。EBI功能域预测发现,在蛋白质序列8-62处有一个BAG功能域。RT-PCR分析表明,TSBAG基因特异性表达于小鼠睾丸组织中且具有时序性表达。TSBAG蛋白在人的同源基因GenBank登录号为AY349359,在233个氨基酸区域内有83%的同源性。结论：TSBAG基因在小鼠睾丸组织中特异性表达,且与小鼠精子发生过程一致。