大豆EST-SSR标记开发及与Genomic-SSR的比较研究*

本研究对458220条大豆EST序列进行SSR搜索,共检测出EST-SSR序列39989条, 经拼接得到无冗余EST-SSR序列8190条,包括357种重复基元。其中二、三核苷酸重复基元类型居多,分别占无冗余EST总数的11.13%和16%,统计得到二核苷酸重复类型12种,三核苷酸重复类型60种。以含有简单重复序列的无冗余EST序列设计200对引物,其中148对引物有清晰且单一条带扩增产物,以30份大豆品种资源进行引物筛选,获得多态性引物31对。以21份大豆不同基因型的基因组DNA为模板选取30对显示多态性的大豆EST-SSR引物和30对大豆基因组SSR引物进行扩增,带型统计结果显示：大豆EST-SSR与基因组SSR在供试基因型间多态性指数均值分别为0.55 和0.44,二者揭示的多态性水平差异不大。从而说明利用生物信息学方法基于大豆EST开发SSR标记是切实可行的,大豆EST-SSR可以用于大豆遗传多样性分析,是大豆DNA分子标记体系的一个重要补充。     

Volatile organic compounds as a diagnostic marker of late blight infected potato plants: A pilot study

Volatiles from potato plants infected with Phytophthora infestans (Mont.) de Bary were monitored by in situ headspace sampling. The sampling was done in four periods i.e. 28–42, 52–66, 76–90, and 100–114 h after inoculation (HAI). The headspace samples were analyzed by a gas chromatography–flame ionization detector (GC–FID) to assess the differences in volatile fingerprints between the infected-plant group and control groups, i.e. non-inoculated-plant and empty-vessel groups. The samples were subsequently analyzed by gas chromatography–mass spectrometry to identify specific peaks observed by GC–FID. Spore germination, infection, symptom development and sporulation were also monitored to ascertain the disease developmental stage when marker volatiles were first generated. The first symptoms of infection were visible after two days. Three marker volatiles i.e. (E)-2-hexenal, 5-ethyl-2(5H)-furanone and benzene-ethanol were found in the third and fourth trapping periods (3–4 days after inoculation) when sporangiophores were already formed. The volatile metabolites from blighted plants could be applied for sensor development to detect the occurrence of the disease in the field as well as for investigation of volatile production in relation to plant responses to infection.     

Insomnia in chronic renal patients on dialysis in Saudi Arabia

Background  

Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.     

黄瓜性型在F1代的遗传表现

选定的基因型范围内,雌性系在性别表达的遗传方面表现为显性性状.在黄瓜品种选育中可以利用雌性系作母本、雌雄同株系作父本选育出接近全雌型的F1,这种F1的雌花节率达到95％以上,完全可以满足生产上的需要.如果父本亦选用纯雌系所得的F1雌花节率将进一步提高,能得到100％的全雌型黄瓜品种.雌性系及其配制的F,第一成花节位均为雌花,这一点不同于雌雄同株型及强雌型品种和材料.试验中第一成花节位与纯雌性状密切相关,在黄瓜品种选育中可以把第一成花节位的性别表现作为鉴定和筛选黄瓜雌性系的参考性状.     

水稻抗感纹枯病品种Ospgip1基因的表达特征

 从水稻基因组DNA中扩增出1 184 bp的Ospgip1基因片段。该片段包含930 bp的完整开放阅读框,终止密码子为TAA,无内含子。RT PCR结果表明,Ospgip1基因在水稻抗、感纹枯病品种中均能表达,但不同生育期、不同部位表达量有差异。实时PCR结果显示,抗病品种YSBR1和中感品种Jasmine 85中Ospgip1的表达量要明显高于感病品种Lemont;稻苗黄化处理后,无论是抗病品种还是感病品种的Ospgip1表达量均显著提高;纹枯病菌侵染使得抗病品种Ospgip1表达量大大增加,而对感病品种影响不大。     

青稞Hva1基因的表达模式及表达载体的构建

为了解青稞种子胚胎成熟晚期丰富蛋白(LEA)基因Hva1与青稞抗旱性的关系,以抗旱性强的旱地紫青稞和抗旱性弱的大麻青稞为材料,研究了不同浓度PEG胁迫下Hva1基因在两个青稞品种中的表达模式。结果表明,Hva1基因在抗旱性不同的两个青稞品种中的表达均呈单峰模式,且抗旱性强的旱地紫青稞表达峰值和对应的PEG胁迫浓度均高于抗旱性弱的大麻青稞;PEG胁迫浓度大于13.18%时,旱地紫青稞的Hva1基因表达量高于大麻青稞。可见,Hva1基因的表达在青稞的抗旱中起到重要的作用,为此我们成功构建了青稞Hva1基因的过量表达载体,期望为抗逆性基因在青稞中的应用和抗旱新品种的选育奠定基础。     

金鱼草花青素糖基转移酶基因的克隆与表达特性分析

以白苏子(Perilla frutescens)花青素糖基转移酶基因为探针,通过电子克隆和RT-PCR的方法从金鱼草(Antirrhinum majus L.)叶片中克隆到花青素糖基转移酶基因(Am GT1)的全长c DNA,并对其表达特性进行分析。结果表明:Am GT1全长892 bp,编码277个氨基酸;进化分析表明Am GT1的氨基酸序列与白苏子的同源性最高为79%,与其他花青素糖基转移酶蛋白的同源性在42%~62%之间,表明Am GT1是从金鱼草中克隆的新的花青素糖基转移酶基因。实时定量RT-PCR分析表明:该基因在金鱼草叶片中的表达量最高,根中的表达量最低;该基因虽然在红色、粉色、黄色、白色花朵中均有表达,但在红色花朵中的表达量最高,且存在一个从紧蕾期到松蕾期的跃变。     

小麦16.9 kD热激蛋白cDNA克隆及其表达分析

为进一步了解小分子量热激蛋白在小麦耐热能力中的作用,根据玉米16.9 kD小分子热激蛋白的氨基酸序列,采用同源序列法进行序列拼接和引物设计,用RT-PCR扩增获得了1个源自小麦叶片的热激蛋白基因cDNA片段,即TaHSP16.9-1(GenBank登录号为EU649679).TaHSP16.9-1全长770 bp,5′非翻译区81 bp,3′非翻译区233 bp,开放阅读框编码151个氨基酸.序列分析结果表明,此蛋白与已知单子叶植物来源的同类基因高度同源,相似性介于78.3%～96.7%之间.定量RT-PCR表达谱分析显示,TaHSP16.9-1在小麦抽穗期的茎和旗叶以及幼苗期叶片中均能表达,其在小麦幼苗叶片中的表达受高温胁迫的诱导.     

橡胶树羟基腈水解酶基因的克隆、表达和基因家族分析

植物体内羟基腈水解酶(HNL)催化羟基腈类化合物水解,释放氢氰酸,抵御害虫和病原菌的侵害。橡胶树是产氰植物,生物信息学研究表明,橡胶树有6个HNL基因,在分子进化分析中与大戟科其他植物的HNL基因聚为一类,与十字花科等植物的HNL亲缘关系较远,说明大戟科HNL基因的重复发生在与十字花科等植物分化之后,大戟科植物通过HNL基因的重复强化对病虫害的防御作用。通过RT-PCR从橡胶树热研7-33-97品系中克隆了其中最重要的1个HNL蛋白编码基因Hb HNL-1。该基因c DNA序列全长1 003 bp,阅读框771 bp,编码257个氨基酸,其编码蛋白分子量为29.2 ku,理论等电点为5.7。定量PCR分析表明,Hb HNL-1在初生胶乳中的表达量是次生胶乳中的100多倍,在幼嫩叶片中的表达量为成熟叶片的8倍。说明橡胶树的幼嫩组织器官是Hb HNL-1的重点防御部位。     

赣棉杂1号在德安的种植表现及栽培要点

赣棉杂1号系江西省棉花研究所选育的高产优质杂交棉品种,2004年3月通过江西省农作物品种审定委员会审定。2005~2007年德安县连续3年试种、示范推广,该品种具有综合性状好,抗性好,产量高等特点,深受广大棉农欢迎,2007年成为江西省棉花首推品种。1品种特性赣棉杂1号全生育期130 d     

稻曲病菌UvHog1基因的克隆及表达分析

稻曲病由稻曲病菌引起,是水稻穗部的重要病害。利用同源克隆和RACE技术,根据丝状真菌相对保守的氨基酸序列设计简并引物,从稻曲病菌中分离了丝裂原活化蛋白激酶(MAPK)编码基因的全长cDNA序列,命名为UvHog1。UvHog1含有MAPK保守的蛋白激酶激活域(TGY),序列与稻瘟病菌MgOsm1(AAF09475.1)、球孢白僵菌BbHog1(AAS77871.1)、烟曲霉AfOsm1(XP752664.1)和隐球酵母CrHog1(AAM26267.1)等MAPK高度同源,相似性分别为95%、93%、88%和81%。系统聚类结果表明,UvHog1与酵母Hog1MAPK同源。在盐胁迫条件下,UvHog1的相对表达量明显降低,表明UvHog1参与了对盐胁迫的信号响应。     

海南龙血树DcbHLH1的克隆与表达分析

碱性螺旋-环-螺旋(basic/helix-loop-helix,bHLH)转录因子在真核生物的生长发育过程中起着重要的调控作用。在前期龙血树转录组测序结果基础上克隆了1个海南龙血树bHLH转录因子基因,命名为DcbHLH1。序列分析显示,DcbHLH1阅读框基因序列长1 080 bp,编码360个氨基酸,推测分子量为39 ku,等电点为8.21。氨基酸序列比对结果显示,DcbHLH1具有bHLH转录因子家族保守的HLH结构域。进化分析结果表明,DcbHLH1和中粒咖啡中的bHLH亲缘关系最近。定量PCR结果表明,DcbHLH1在诱导剂处理后3 d内表达量快速下降,到第6天达到最低,与转录组测序的数字表达谱一致。DcbHLH1在海南龙血树的根、茎、叶等组织中均有表达,但在叶中表达量较高,根中表达量最低。结果为进一步分析DcbHLH1在龙血树中的功能奠定了基础。     

小麦SGT1基因的克隆与表达特性分析

为了研究SGT1基因在不同小麦抗病反应中的表达特性,采用RT-PCR和RACE方法,从小麦cDNA中分离出包含SGT1基因全长cDNA序列.该基因编码具有377个氨基酸的蛋白,具有已知SGT1蛋白典型的5个功能域,即TPR区、VR1区、CS区、VR2区和SGS区.小麦SGT1蛋白与大麦SGT1蛋白的氨基酸序列具有97%的相似性.Southern杂交结果显示,SGT1基因在小麦基因组中有3个拷贝.分析结果表明,大麦黄矮病毒、白粉病菌、纹枯病菌和赤霉病菌侵染小麦均可诱导小麦SGT1基因转录水平上调,说明SGT1可能参与了小麦不同抗病反应.     

Molecular marker for screening rice cultivars with intermediate amylose content in indica

The waxy (Wx) gene of rice encodes the granule-bound starch synthase(GBSS), which was required in the synthesis of amylose in endosperm. The anylose content (AC) of rice endosperm played an important role in grain yield,palatability, and processing quality.     

Molecular marker for screening rice cultivars with intermediate amylose content in indica

The waxy (Wx) gene of rice encodes the granule-bound starch synthase(GBSS), which was required in the synthesis of amylose in endosperm. The anylose content (AC) of rice endosperm played an important role in grain yield,palatability, and processing quality.     

胡椒PnNPR1基因的克隆与表达分析

根据胡椒病程相关基因非表达子1(Nonexpressor of pathogenesis-related genes1,NPR1)基因的部分序列设计引物,运用RT-PCR方法获得其家族成员的1个全长c DNA,命名为Pn NPR1,长度1 712 bp,开放阅读框1 362 bp,编码454个氨基酸。预测Pn NPR1分子量为141.56 ku,理论等电点为4.98。该基因含有BTB/POT结构域、ANK锚蛋白重复序列、DUF和NPR1-like C等4个结构域,具有植物NPR1所共有的保守结构域。系统进化分析表明,Pn NPR1与苜蓿的同源性最高。Real-time RT-PCR结果表明,Pn NPR1在胡椒叶片、根、茎和花中均表达,在叶中的表达量最高。辣椒疫霉菌诱导后,Pn NPR1基因的表达量在抗/感2种胡椒中均出现先增加后减少的现象,并且在抗病种质中表达量较高。研究结果为Pn NPR1的功能研究提供了理论依据。     

大豆再生相关基因GmESR1的克隆及其表达分析

利用同源克隆技术,对拟南芥再生相关基因ESR1进行同源序列比对,得到大豆再生相关基因GmESR1.结果表明,大豆再生相关基因GmESR1全长1 164 bp,转录区为981 bp,编码326个氨基酸,含有一个AP2/ERF结构域,属于AP2家族成员.对大豆叶片进行细胞分裂素处理,实时定量PCR技术分析表明细胞分裂素能明显促进GmESR1基因表达.     

小麦高分子量谷蛋白亚基1Dx5基因在大肠杆菌中的表达

为了给小麦优质亚基研究奠定基础,将高分子量谷蛋白亚基1Dx5基因的核苷酸序列与载体pRSET A重组,将构建好的质粒转化大肠杆菌BL21(DE3)pLysS菌株,通过IPTG使其得到了成功表达.大肠杆菌中表达的1Dx5亚基在SDS-PAGE上与小麦品种钱尼中的1Dx5亚基具有相似的迁移率.用Western blot技术成功检测到了目的基因产物.通过改变IPTG浓度、诱导时间、培养基成分及初始菌液浓度研究了最适表达条件.结果表明,最适表达条件为:LB培养基,菌液初始浓度(OD600)0.4～0.6,IPTG浓度0.4mmol/L,诱导时间为3～5 h.     

Molecular characterization of Cereal Cyst Nematode diagnostic markers Cre1 and Cre3 in some winter wheat germplasm and their potential use against Heterodera filipjevi

Two PCR based markers tightly linked to Cre1 and Cre3 resistant genes against the Cereal Cyst Nematode (CCN, causal agent Heterodera avenae) were used to characterize a number of diploid, tetraploid and hexaploid wheat germplasm consisting of obsolete, advanced lines and new cultivars from the Turkish National Breeding Program and the joint TURKEY CIMMYT ICARDA International Winter Wheat Improvement Program. In addition a number of landraces and wild relatives of wheat collected from the Turkish side of the Fertile Crescent, the centre of origin of cereals, were included. None of the genetic material tested positive for either marker except the land race Sardari which originated from neighboring Iran was found positive for Cre1 gene. Combining both of these molecular markers in one assay for fast and cost-effective screening of the germplasm was not effective, so marker genotyping with germplasm was realized using each primer alone. Most work that has been reported is on the CCN species H. avenae, however the predominant species in Turkey is the closely related H. filipjevi. In vitro resistance assaying for this species indicates that Cre1 is a moderate source of resistance against the H. filipjevi population, however Cre3 gene appears ineffective. It is suggested that a larger pool of a range of germplasm should be screened for Cre1 in Turkey. Furthermore, the landrace Sardari could be used as a parent to deploy CCN resistance in to genetic background of Turkish bread wheat cultivars with a targeted Marker Assisted Selection Backcrossing approach.     

Significance of furosine as heat-induced marker in cookies

The effects of recipe formulation in terms of leavening agents (ammonium and sodium bicarbonates), sugars (sucrose and glucose), initial moisture content, and baking conditions (temperature and time) on furosine formation in cookies were studied. The cookies were baked at different temperatures for different times to monitor the progress of the early stage of the Maillard reaction. Change in furosine levels as an indicator of the Amadori products showed a typical kinetic behavior with a rapid increase to an apparent maximum followed by exponential decrease during baking. Initial water activity of cookie dough had no remarkable effect on the apparent maximum, but lowering the water activity decreased the time required to attain it. In addition, levels of furosine in the final product are highly correlated to the initial water content of dough at the same baking conditions. The levels of furosine attained were significantly lower in cookies composed of sucrose than in cookies composed of glucose. Early stage of the MR is rapidly overcome during baking as the Amadori product degraded in the advanced stage. Among the leavening agents, ammonium bicarbonate was the most effective for the progress of the Maillard reaction in cookies during baking.