龙血树DCDPK2基因的克隆及表达分析

通过RACE技术克隆龙血树CDPK基因的全长cDNA,并对基因序列进行相关分析与基因表达分析。结果表明:该基因全长为1 810 bp,编码区长度为1 587 bp,编码528个氨基酸,其氨基酸序列具有CDPK基因编码氨基酸的所有典型结构特征;经序列比对发现其核酸序列与玉米CDPK基因的同源性高达81%,氨基酸序列与其它植物中的CDPK氨基酸序列同源性很高。该基因命名为DCDPK2基因。对未经血竭诱导和诱导的龙血树组培苗进行半定量RT-PCR表达分析,发现在添加了诱导物的组培苗中DCDPK2基因的表达显著增强。     

早钟6号枇杷两个ETR基因成员的克隆及序列分析

以早钟6号枇杷的试管苗叶片为材料,采用同源克隆方法得到乙烯受体基因ETR的两个成员Ej-ETR1a和Ej-ETR2a的cDNA全长序列,在GenBank上的登录号为JX307084和JX307089.Ej-ETR1a序列全长2771 bp,包括227bp 5’-UTR、2226 bp ORF及318 bp 3’-UTR; Ej-ETR2a序列全长2594 bp,包含2226 bp ORF及366 bp 3’-UTR.Ej-ETR1a、Ej-ETR2a均编码741个氨基酸,且氨基酸序列具有95.28％的相似性.生物学信息分析表明:枇杷Ej-ETR1a和Ej-ETR2a均属于乙烯受体ETR1亚家族,为一个具有跨膜结构的非分泌蛋白,具有疏水性.2个ETR成员的克隆为进一步研究枇杷乙烯受体作用机制奠定了基础.     

玳玳花瓣脂氢过氧化物裂解酶基因cDNA的克隆及原核表达

以玳玳花瓣为材料,采用RT-PCR和RACE技术,克隆了玳玳HPL基因cDNA全长,全长为1 776 bp,其中包含52 bp的5′非编码区,224 bp的3′非编码区,1 500 bp的编码区(编码499个氨基酸,分子量为55.7 ku)。将该HPL基因cDNA编码区的核苷酸序列及所推导的氨基酸序列与其他植物的HPL基因cDNA序列进行比较,推断玳玳花瓣HPL属于13-HPL类。通过PCR扩增得到了玳玳HPL基因组全长。测序结果显示玳玳HPL基因中包含1个长2 374 bp的内含子。将分离出来的玳玳HPL基因cDNA的编码区序列插入pET-15b载体上构建原核表达载体,在细菌BL21细胞中进行原核表达。结果表明:该编码区片段可在原核细胞中大量表达,其表达产物分子量大小约为55 ku,与13-HPL蛋白的分子量55.7 ku相符。本研究为下一步利用HPL基因cDNA进行遗传转化研究奠定基础,将为花卉香味的遗传改良提供一条新途径。     

青稞新光合作用相关基因的克隆和序列分析

根据鉴定得到的青稞4个光合作用相关基因的序列设计引物,从青稞叶片的c DNA中扩增得到目的片段,并对目的基因序列进行测序鉴定和序列分析。结果成功扩增出4个基因的序列,大小分别为513、822、1023和579 bp。生物信息学分析表明,02833基因可能编码一个核糖-5-磷酸异构酶3;03360基因可能编码一个273个氨基酸的核酮糖-磷酸-3-异构酶,该蛋白属于ICL_KPHMT superfamily之一,推测其CDS全长为822 bp;45441基因可能编码一个340个氨基酸的苹果酸脱氢酶,该蛋白属于Ldh_1_C superfamily之一,推测其CDS全长为1 023 bp;45453基因可能编码一个果糖-1,6-二磷酸激酶。这些基因的克隆为研究青稞的光合机制奠定了基础。     

胶孢炭疽病菌环境pH应答转录调控因子基因的克隆与分析

参照油梨炭疽病菌(Colletotrichum gloeosporioides)的环境pH应答转录因子基因Pacl设计l对特异性引物,以芒果炭疽病菌(C.gloeosporioides)基因组DNA为模板,扩增获得大小为2 625 bp的目的基因片段.序列分析结果表明,目的片断包含完整的阅读框,与油梨炭疽病菌C.gloeosporioides pac1基因相应片段长度相同,二者碱基序列同源性达97%.用RT-PCR技术获得pacl基因cDNA片段,证实目的基因片段中存在3个大小分别为59,50,71 bp的内含子.拼接的全长cDNA长1 755 bp,推测编码的氨基酸序列长584个氨基酸残基,与推测的油梨炭疽病菌pacl基因所编码的蛋白质同样大小,二者氨基酸序列相似性达99%,只有1个氨基酸的差异,可以肯定克隆的目的片段为C.gloeosporioides pac1基因,为进一步研究C.gloeosporioides侵染芒果时的pH调控奠定了基础.     

花生△12-脂肪酸脱氢酶基因的克隆及序列分析

根据已报道的△12-脂肪酸脱氢酶基因(FAD)的氨基酸保守序列设计引物进行RT-PCR扩增,得到花生△12-脂肪酸脱氢酶基因881bp部分cDNA序列,然后通过快速扩增cDNA末端技术(RACE),向两端延伸得到1410bp的花生△12-脂肪酸脱氢酶基因全长cDNA序列。序列分析表明有一个长1140bp、编码379个氨基酸残基的开放阅读框,所编码蛋白质的大小约为43kDa。推测的氨基酸序列具有膜整合蛋白酶特异性的3个组氨酸保守区;氨基酸疏水性分析结果表明,所编码的氨基酸序列存在2个具有膜固定蛋白(membrance-anchored protein)重要特征的疏水结构,2个疏水区共跨膜4次,这些特性表明所获得的序列为△12-脂肪酸脱氢酶基因。     

花生(Arachis hypogaea L.) CaM基因克隆与序列分析

提取花生(Arachis hypogaea L.)幼嫩叶片基因组DNA,合成5'端和3'端引物,进行PCR并克隆测序,得到CaM基因组的2个异型基因PGCaM-1和PGCaM-3,登录Genebank并注册为AY517933、AY572856。序列分析表明,PGCaM-1序列全长1425 bp,在第25个氨基酸之后有一个长度为973 bp的内含子,PGCaM-3序列全长447 bp。两个异型基因的开放读码框均由447个核苷酸组成,共编码148个氨基酸,同属于EF手型CaM超家族成员,核苷酸和氨基酸序列的同源性分别为96%和98%,与已知花生CaM cDNA序列及氨基酸均有极高的同源性,序列之间的差异可能引起表达和功能上的差异。     

橡胶树HbDHN1基因克隆及表达分析

采用Macroarray印迹杂交技术从本实验室构建的橡胶树机械伤害诱导的树皮抑制性差减杂交(SSH)cDNA文库中检测到1个差异表达EST.采用RT-PCR和RACE技术获得了该基因全长cDNA序列,包括124 bp的5'端非编码区,337 bp的3'端非编码区和1个编码224个氨基酸的开放阅读框.该cDNA编码的蛋白具有植物脱水素蛋白的特征性结构,属于SK2类脱水素蛋白.命名为H6DDHN1,与其它植物的SK2类脱水素蛋白具有49.0%～68.2%的氨基酸序列同源性.RT-PCR分析表明,机械伤害对HbDHN1基因的表达没有明显影响,受伤组织的脱水显著上调该基因的表达.     

茶尺蠖普通气味结合蛋白(GOBP)的基因克隆与序列分析

以触角总RNA为模板,根据同源性设计简并性引物,采用RT-PCR扩增结合RACE技术克隆获得了茶尺蠖(Ectropis obliqua)普通气味结合蛋白GOBP1和GOBP2基因的cDNA全长序列。分别命名为EoblGOBP1和EoblGOBP2。EoblGOBP1的cDNA全长为1 528 bp,开放阅读框501 bp,编码166个氨基酸残基,预测分子量Mw=18 835.63 D,等电点pI=5.45,cDNA和氨基酸序列在NCBI/GenBank的登录号分别为FJ156732和ACN29680.1。EoblGOBP2的cDNA全长为1 315 bp,开放阅读框405 bp,编码160个氨基酸残基,预测分子量Mw=18 002.75 D,等电点pI=5.32。cDNA和氨基酸序列在NCBI/GenBank的登录号分别为FJ156733和ACN29681.1。两个气味结合蛋白的氨基酸序列中都含有6个保守的半胱氨酸位点,具有气味结合蛋白的典型特征,与已报道的鳞翅目昆虫气味结合蛋白的同源性为分别62%～82%和76%～88%。     

小麦自主开花基因TaFLD单核苷酸多态性分析

为了给培育具有广泛生态适应性的小麦品种提供参考依据,通过比对拟南芥自主开花基因(FLD基因)与小麦D基因组序列,获得小麦FLD基因的同源序列.分析结果表明,小麦TaFLD基因全长8 392 bp,具有3 087 bp完整ORF,编码1 028个氨基酸,亚细胞定位预测显示,其编码蛋白定位于细胞质.TaFLD基因功能预测表...     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).