Mutant acetolactate synthase （ALS） gene as a selectable marker for Agrobacterium-mediated transformation of soybean

Soybean is one of the crops most difficult to be manipulated in vitro. Although several soybean marker genes, all the selectable markers used were from bacteria origin. To find suitable selectable marker gene from plant origin for soybean transformation, a mutant acetolactate synthase （ALS） gene from Arabidopsis thaliana was tested for Agrobacterium-mediated soybean embryo axis transformation with the herbicide Arsenal as the selective agent. Transgenic soybean plants were obtained after the herbicide se- lection and the To transgenic lines showed resistance to the herbicide at a concentration of 100 g/ha. ALS enzyme assay of To transgenic line also showed higher activity compared to the wild type control plant. PCR analysis of the T1 transgenic lines confirmed the integration and segregation of the transgene. Taken together, our results showed that the mutant ALS gene is a suitable selectable marker for soybean transformation.     

利用人内皮抑素基因构建植物表达载体及对烟草的遗传转化

将人内皮抑素(endostatin)基因重组于植物双元表达载体pGA 643,得到重组质粒pGE.用三亲融合法将其导入农杆菌LBA 4404中,采用叶盘法转化烟草,经诱导与筛选,获得了卡那霉素抗性植株.提取抗性植株总DNA,通过PCR扩增和Sou thern杂交检测,筛选出了整合有外源基因的转化植株.为进一步研究人内皮抑素在烟草中的表达及生物学功能奠定了基础.     

大肠杆菌巴豆甜菜碱还原酶基因缺失菌株的构建

报道了体外构建caiA基因缺失的带有卡那霉素抗性基因的5．2kb线状DNA分子,以此转化大肠杆菌JM83和BL21(DE3)株,借助于体内DNA同源重组,定向敲除了大肠杆菌中的巴豆甜菜碱还原酶编码基因caiA。经遗传稳定性实验、聚合酶链反应(PCR)以及Southern鉴定,表明所获得的JM83转化子22号和BL21(DE3)转化子4号确为caiA基因缺失突变株;酶活分析结果表明,22号和4号转化子均丧失了巴豆甜菜碱还原酶活性。     

Molecular characterization of GmNHX2, a Na＋/H＋ antiporter gene homolog from soybean,and its heterolosous expression to improve salt tolerance in Arabidopsis

Na＋/H＋ antiporters have been well documented to enhance plant salt tolerance by regulating cellular ion homeostasis. Here, a putative Na＋/H＋ antiporter gene homolog GmNHX2 from soybean was cloned and predicted to encode a protein of 534 amino acids with 10 putative transmembrane domains. GmNHX2 was expressed in all soybean plant tissues but enriched in roots and its expression was induced by NaCI and polyethylene glycol （PEG） treatments. GmNHX2 exhibits greater sequence similarity with LeNHX2 and AtNHX6 than that of AtNHX1 and AtSOS1. Although phylogenetic analysis clustered GmNHX2 with organellar （tonoplast and vesicles） antiporters, the GmNHX2-EGFP （enhanced green fluorescent protein） fusion protein was possibly localized in the plasma membrane or organelle membrane of transgenic plant cells, Furthermore, transgenic Arabidopsis plants expressing GmNHX2 were more tolerant to high NaCl concentrations during germination and seedling stages when compared with wild-type plants. These results suggest that GmNHX2 is a membrane Na＋/H＋ antiporter and may function to regulate ion homeostasis under salt stress.     

OsNHX1基因转化84K杨的研究

采用农杆菌介导的方法开展了水稻Na /H 逆向转运蛋白基因OsNHX1转化84K杨的研究.建立了84K杨的叶外植体高频再生系统,经诱导不定芽及诱导生根阶段卡那霉素连续筛选,获得了大量卡那霉素抗性转化植株.PCR检测和Southern杂交检测表明,OsNHX1基因已成功整合到84K杨基因组.耐盐实验表明,转基因植株能在200 mmol NaCl条件下正常生长.     

农杆菌介导的DREB1A基因转化多花黑麦草及其转化体系的优化

采用携带卡那霉素抗性基因nptII和GUS基因的ubiquitin启动子驱动的表达载体pBI121／DREB1A的根癌农杆菌AGL1, 对多花黑麦草幼胚来源的胚性愈伤组织进行了遗传转化,并优化了各种影响因素。胚性愈伤组织经根癌农杆菌感染和共培养后,用50mg／L巴龙霉素筛选抗性愈伤组织,待抗性愈伤组织在IB分化培养基上分化成苗后用25mg／L卡那霉素进一步筛选再生植株, 获得了部分抗性植株。抗性植株的总DNA用DREB1A基因的特异引物进行PCR检测,转化频率为2.14％,PCR-Southern blot进一步验证了转化植株基因组中含有该外源基因。各种影响转化效率因素的优化实验表明,当转化时菌液浓度的OD600为2.0、侵染时间为1h、共培养时间为2d、共培养温度为21℃及在共培养期间使用乙酰丁香酮等,均可明显提高转化频率。     

Comparative expression analysis of three genes from the Arabidopsis vacuolar Na^＋/H^＋ antiporter （AtNHX） family in relation to abiotic stresses

Na~ /H~ antiporters (NHX) are ubiquitous transmembrane proteins that play a key role in salt tolerance of plants. In this study, the sequence of 3 Arabidopsis NHX gene (AtNHX2―4) were compared with other AtNHX members. Putative cis-elements analysis identified elements that have been associated with stress responses. The activities of the promoters AtNHX2―4 were studied in transgenic plants carrying corresponding promoter-β-glucuronidase (GUS) fusions. The AtNHX2 promoter-GUS analysis indicated that AtNHX2 was expressed in constitutive pattern with high GUS activity in roots and leaves. AtNHX2 promoter activity was not up-regulated by NaCl or abscisic acid (ABA), in contrast to the AtNHX1 promoter which was previously studied. The AtNHX3 and AtNHX4 promoters showed tissue-specific activities. Strong GUS activity was detected in roots and vascular bundles of the stele in plants carry-ing an AtNHX4 promoter-GUS fusion, and GUS activity increased under salt stress suggesting a func-tion related to salt tolerance. Transgenic plants carrying the AtNHX3 promoter-GUS fusion showed strong GUS activity in petals, stamens and tops of siliques, suggesting a possible role of AtNHX3 in flower and seed development. Results of histochemical analysis suggested that AtNHX2―4 are involved in divergent functions and are differentially regulated under abiotic stress. The structure of AtNHX4 was predicted to include 12 transmembrane regions and a NHX domain. Overexpression of AtNHX4 in Arabidopsis transgenic lines confers greater salt tolerance than in wild type plants. These results suggest that AtNHX4 may encode a putative vacuolar NHX that plays an important role in salt tolerance.     

用Ti质粒的双元载体法将抗性基因转入西红柿体细胞

采用Ｔｉ质粒的双元载体法对西红柿（Ｌｙｃｏｐｅｒｓｉｃｏｎｅｓｃｕｌｅｎｔｕｍ）的叶片外植体进行遗传转化，经选择培养基的筛选，从抗性愈伤组织细胞中诱导出具有卡那霉素抗性的幼苗．分子杂交证实，卡那霉素抗性基因通过根瘤农杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍｔｕｍｅｆａｃｉｅｎｓ）的介导，整合到细胞核基因组中，转化子具有较高的新霉素磷酸转移酶活性，说明抗性基因在受体细胞得到表达．     

农杆菌介导外源基因进入油菜的研究

用甘蓝型油菜子叶为外植体，以农杆菌共培养法将苏云金杆菌δ－内毒素基因和ＮＰＴＩ基因导入油菜．所用的农杆菌为ＬＢＡ４４０４－δ（ｄｉｓａｒｍｅｄｐＡＬ４４０４，ｐＧＡ６４３－δ）．ＰＧＡ６４３－δ为表达载体，其中克隆有ＮＰＴＩ基因和δ－内毒素基因．共培养４ｄ后，转化的子叶被转入含有卡那霉素（Ｋｍ）的分化培养基［１］上，分化出芽．被切下的芽在含有Ｋｍ的生根培养基［２］上生根，移栽后成活的小抗Ｋｍ油菜苗生长良好．用ＤＮＡ分子杂交、ＥＬＩＳＡ分析和生物测定等方法证明外源基因被转移到油菜中．     

Multiple transgenes Populus xeuramericana ''''Guariento'''' plants obtained by biolistic bombardment

A JERF36 regulation gene, a selection marker gene (NPT-II), and the foreign genes levansucrase (SacB), Vitreoscilla hemoglobin (vgb), and Binary coleopterus insect resistance (BtCry3A OC-I) were co-transferred into Populus xeuramericana 'Guariento' using biolistic bombardment; 25 kanamycin resistant plants were obtained. The results of PCR and Southern hybridization showed that the foreign genes had been integrated into the genome of P. xeuramericana 'Guariento' and 5 genes were all transferred into 7 poplar plants. The results of a BtCry3A ELISA experiment indicated that the BtCry3A gene was expressed in the 7 transgenic poplar plants, and these plants grew well on coastal saline land.     

辣椒的离体再生及抗虫基因转化的研究

研究建立起一套简单、高效的辣椒遗传转化系统。利用根癌农杆菌介导带柄子叶,将豇豆胰蛋白酶抑制剂（CpTI)基因转入辣椒栽培品种“益都羊角椒”中。对获得的33株卡那霉素（Km)抗性植物进行PCR检测,证明有6株为转CpTI基因植株。通过对转基因植株进行抗虫性研究,发现R1代植株对棉铃虫表达出一定的抗性,但不同转化体之间其抗性存在着差异。     

Studies on the overexpression of the soybean GmNHX1 in Lotus corniculatus： The reduced Na^＋ level is the basis of the increased salt tolerance

Soil salinity is one of the major factors reducing plant growth and productivity. The detrimental effects of salt on plants are a consequence of both a water deficit resulting in osmotic stress and the excess so- dium ions on critical biochemical processe…     

Expression of lysine-rich protein gene and analysis of lysine content in transgenic wheat

Expression vector pBPC102, which carries winged bean lysine-rich protein (wblrp) gene and dihydropicolinate synthase (DHDPS) gene, was transferred into hexaploid winter wheat cv. Jinghua No.l, Jing411, You899 and Yangnongl5 explants of immature inflorescence and immature embryos by particle bombardment. More than 100 transgenic plants were obtained under the selection of s-(2-aminoethyl)-L-cysteine (AEC). Confirmed transgenic plants of To and TI generation by PCR and PCR-Southern blotting analyses showed successful integration of wblrp gene into wheat genome. Analysis of transgenic plant lines of T2 by Northern dot-blotting showed good expression of wblrp gene in offspring seed. The content of free lysine in leaves, contents of bound lysine and total proteins in seeds of T2 transgenie wheat lines were determined and analyzed. Among 34 tested transgenic lines, levels of free lysine content in leaves of 9 transgenic lines are 2~3times higher than un-trans-formed wild-type cultivars. Among 17 analyzed transgenic lines, bound lysine content of 4 transgenic lines is more than 10% higher than that of wild-type cultivars. Our research suggests that introducing wblrp gene into wheat is an effective way to improve its nutrition quality.     

Molecular markers linked to Rsa resistant to soybean mosaic virus

Soybean mosaic virus (SMV) is a severe disease in worldwide soybean production. A cross was made between Kefeng No. 1 with broad spectrum resistance to SMV and Nannong 1138–2, a susceptible cultivar. The inheritance of resistance to SMV strain Sa prevailing in southern China was analyzed. Results of x² test from inoculation experiment on parents F1, F2 and F3 lines showed that the resistance to strain Sa was controlled by a single dominant gene Rsa. BSA method was adopted and 900 random 10-mer primers were used to amplify total DNA from resistant pool and susceptible pool in order to obtain polymorphic bands in two bulks. 16 primers could generate polymorphic bands, of which OPW-05 and OPAS-06 could generate the most stable RAPD patterns. RAPD markers OPW-05₆₆₀ and OPAS-06₁₈₀₀ were found to be linked to Rsa. Their order and genetic distance were OPAS-06₁₈₀₀22.2cM Rsa10.1 cM OPW-05₆₆₀. Southern blotting showed that both OPAS-06₁₈₀₀ and 0PW-05₆₆₀ were low copy DNA in genomic DNA. 0PW-05₆₆₀ has been converted into an RFLP marker successfully. Additionally, pK644H, an RFLP marker, has been identified to be linked to 0PW-05₆₆₀, and their genetic distance was 37.4 cM.     

转基因棉PCR与卡那霉素检测的比较

对尚未提纯的转基因棉１７９自交后代进行卡那霉素检测和ＰＣ检测,结果表明卡那霉素检测与ＰＣＲ检测结果一致;抗卡那霉素植株ＰＣＲ检测均呈阳性,而对卡那霉素敏感植株均未扩增出特异性带。     

农杆菌介导人肝再生增强因子转化河套蜜瓜的研究

利用三亲融合法将含有人肝再生增强因子(hum an augm en ter of liver regeneration,hALR)的果实特异性表达载体pPZP-CAN导入农杆菌LBA 4404,转化河套蜜瓜子叶外植体,经诱导与筛选获得了抗性再生植株,PCR扩增、PCR-Sou thern和斑点杂交检测证明hALR已整合入河套蜜瓜再生植株基因组中.     

大豆自花授粉后外源DNA导入技术的验证

以花生DNA为供体,大豆为受体,在大豆自花授粉后,采用液滴法和注射法导入花生DNA,在受体大豆植株后代中获得了多种变异类型。为探讨外源DNA 导入技术的可靠性,将具有卡那霉素抗性基因的质粒pCaMVneo 用同法导入大豆。所收获的种子发芽后培养于一定浓度的卡那霉素溶液中,其中部分植株对卡那霉素表现抗性,可继续生长发育。分株提取这些植株的DNA,以质粒DNA 为探针,进行斑点杂交.供试的14个植株中出现了13个阳性斑。实验结果证明质粒DNA 已整合到大豆基因组中并获表达,从而间接地证实了授粉后通过花粉管通道导入外源DNA 的技术是可靠的。     

转AlNHX1基因大豆后代遗传稳定性及耐盐性分析

为了获得耐盐性有所提高的转AlNHX1基因大豆后代材料,以已获得的转AlNHX1基因的6个株系中的3个株系后代为研究对象,通过分别对这3个株系转基因大豆各后代进行PCR分子检测并结合耐盐性鉴定,以分析外源基因在转基因大豆中遗传稳定性和耐盐性.结果表明:AlNHX1基因在转基因植株的后代中遗传;选取3个株系中部分阳性植株做耐盐性检测,结果表明:转基因大豆耐盐性状均好于野生型大豆.在150mmol/L NaCl胁迫下,转基因大豆叶片中维持了相对较高的K+/Na+比值,相对含水量较野生型提高了9%,而渗透势降低了39%,表明转基因大豆具有较好的吸水和保水能力;在盐胁迫下,超氧化物歧化酶(SOD)与过氧化物酶(POD)活性较野生型大豆分别提高了45%与69%.综上,通过耐盐筛选获得的转AlNHX1基因大豆具有较强的耐盐性.     

Isolation and characterization of soybean NBS analogs

Isolation of plant resistance genes is greatly helpful to crop resistance breeding and the insight of resistance mechanism. The cloned plant resistance genes are classified into four classes according to their putative structural domain, of which the majority possesses nucleotide-binding site (NBS) domain that consists of P-loop, kinase2a and kinase3a. The conservation of this domain affords the potential possibility of cloning the plant resistance genes, which is homology-based cloning technique. In the present study, the degenerate oligonucleotide primers were designed according to the tobaccoN andArabidopsis RPS2, and 358 clones were isolated from the genomic DNA of resistance soybean cultivar Kefengl, resistant to soybean mosaic virus, and 4 open-reading NBS analogs were finally characterized and designated asKNBS1, KNBS2, KNBS3 andKNBS4. Southern hybridization suggested that they were present with multicopy in the soybean genome;KNBS4 was mapped to F linkage group andKNBS2 co-located J linkage group with the SCAR marker ofRsa resistant to soybean mosaic virus by RFLP analysis. Northern analysis suggested thatKNBS2- related sequence was low and constitutively expressed in the root, stem and leaves of soybean. The detailed characterization of NBS analogs is very helpful to ultimately cloning the soybean resistance gene.     

水稻基因整合平台系统供体质粒pURKMT的构建

提高水稻产量,改良稻米品质是育种学家广泛研究的课题．随着现代生物技术的发展,水稻已成为植物基因工程的重要研究对象．许多实验室已成功地建立了一系列供外源基因转化水稻的系统．但是这些转化系统主要应用Ｔｉ质粒衍生的载体,通过Ｔ－ＤＮＡ左右两端的序列将目的基...