农杆菌介导大豆遗传转化研究进展及转基因作物现状

利用转基因技术将目的基因导人植物受体细胞,使目的基因在植物受体中表达,从而获得优良性状的植株,达到快速培育植物新品种的目的.将植物基因工程技术与常规育种技术相结合,在培育优质、高产和抗逆植物新品种中具有巨大潜力.目前,在各种转基因物种中,大豆仍是难转化的作物之一,建立有效的转化系统是改良大豆品质性状和研究大豆功能基因的先决条件.综述农杆菌介导大豆遗传转化分子机理,影响大豆遗传转化因素,提高大豆转化效率的最新研究进展及转基冈大豆生产现状.     

转基因作物的基因流研究概况

转基因作物是指利用转基因技术改变作物的某些遗传特性从而获得新的优质丰产的遗传性状的作物。这些性状包括抗虫性、抗病性、抗除草剂、抗逆境、延迟衰老、改变花色、改变熟期、雄性不育及改良种子的营养价值等方面。自从1983年第一株转基因植物诞生以来,全世界进入     

大豆遗传转化技术研究进展

近年来,随着植物基因工程的快速发展,利用转基因技术进行大豆分子育种和基因功能研究成为一种重要手段。现阶段大豆转基因的研究重点主要集中在大豆遗传转化的方法和建立高效、稳定地遗传转化再生体系方面。本文对大豆遗传转化相关方法、转化再生体系及转化效率相关的因素进行了阐述,为大豆遗传转化及转基因新品种培育等相关研究提供参考。     

转基因水稻后代中外源基因的遗传表达及其对非目标性状的影响

转基因技术是进行水稻品种遗传改良的一种新的技术手段。综述了近年来国内外转基因水稻后代目标性状的遗传表达及其影响因素、外源基因导入对水稻受体非目标性状的影响及其产生变异的原因、转基因水稻杂交配组应用等方面的研究进展。     

大豆品质改良的基因工程育种概况

通过基因工程育种改良的大豆遗传性状,使其具有更高的营养价值和经济价值,已成为当今大豆遗传育种研究的热点.已经成功选育了多种品质性状优良的转基因大豆材料或品系,包括高油酸大豆,高亚麻酸大豆,高含硫氨基酸大豆,高赖氨酸大豆等.本文综述了大豆品质改良的基因工程育种进展,对当前已获得的转基因大豆的品质性状特点作了介绍.     

利用大豆潜力实现可持续农业发展和粮食安全

大豆是牲畜饲料的重要来源,然而气候环境变化对大豆产量、品质和安全影响严重,因此迫切需要培育适应气候变化负面影响的大豆新品种。现代生物技术的发展促进数量性状位点的基因挖掘,通过转基因的方式辅助育种进而培育高产量和高品质的大豆品种。此外,转基因技术还可以用来操纵植物的遗传组成,提高饲料的消化率,从而提高动物的性能。对大豆在提供优质饲料方面的遗传潜力进行了评价。同时探讨了气候变化对饲料质量的影响,并讨论了在增强植物对非生物胁迫条件的适应方面所做的努力。     

大豆抗旱性的遗传改良研究

干旱是影响大豆产量重要限制因素,进行大豆抗旱性的遗传改良研究,培育抗旱高产大豆新品种是有效解决干旱胁迫的最有效途径.在调动C3作物大豆内在C4途径来提高光合效率的大豆高光效育种总体思路基础上,提出了大豆抗旱性遗传改良的两条技术路线,即转抗旱内源或外源基因的转基凶育种技术路线和高光效育种及回交转育的技术路线,并指出二者具有异曲同工、殊途同归的效果.同时着重论述了大豆品种抗旱性与丰产性关系,耐光氧化特性与抗旱性关系,植物抗旱相关基因研究概况及QTL标记辅助选择抗旱育种的方法.旨在为大豆抗旱性的遗传改良提供相关理论依据和技术支撑.     

诱变育种技术在大豆育种与基因挖掘中的应用现状及展望

植物诱变育种能够创造许多优异变异资源,诱变获得的突变体可以作为种质材料,为大豆新品种培育提供丰富的资源;构建的突变体库也有助于大豆功能基因组研究的开展,可为特定性状的研究提供遗传材料。本文介绍诱变育种技术在大豆生长特性、品质和抗性改良育种中的应用,分析利用诱变突变体库进行大豆生长特性、品质性状改良和抗性相关基因挖掘的研究进展,介绍诱变技术与其他生物技术相结合发掘目的基因的应用现状,并展望今后大豆诱变育种技术在基因挖掘方面的应用前景,以期能更好地运用诱变育种技术推动大豆遗传研究和品种选育。     

IFS转基因大豆的鉴定及高异黄酮植株的筛选

大豆异黄酮是一种广泛应用的保健性活性物质,近年来已成为衡量大豆品质的重要指标之一。异黄酮合酶是大豆异黄酮合成途径中的关键酶基因之一,其在植物中的表达效率直接影响异黄酮含量。为进一步验证该基因的功能并获得高异黄酮稳定遗传转基因植株,本试验基于已有的IFS转基因材料开展研究。将其扩繁至T2代,考种分析植株农艺性状,发现转基因植株的性状指标未发生明显变化,PCR鉴定IFS转基因后代的结果显示:在125株转基因植株中,60株为阳性,占比48%,说明IFS在后代中可稳定遗传。选取IFS转基因吉林35、Willimas 82品种T2代的41株,利用改良后的三波长法测定籽粒中大豆异黄酮的含量,结果显示:IFS转基因植株的平均异黄酮含量为1.2 mg·g~(-1);其中15株的异黄酮含量高于非转基因植株,占比达到36.6%,说明从转入IFS基因转基因大豆能够筛选出高异黄酮植株。本研究获得了稳定遗传的高异黄酮植株,为大豆遗传育种提供优异的种质资源;改良后的三波长法较原有方法更为精准、快速。     

大豆炸荚基因GmAGL8的转基因鉴定与功能初探

炸荚是大豆的一种自然特征属性,是影响大豆产量的重要因素之一。本研究以前期获得的转大豆炸荚相关基因GmAGL8的T_1代植株为材料,继续繁育获得T_2和T_3代;采用PCR和RT-q PCR检测方法对转基因植株进行基因遗传稳定性和表达情况分析;并以野生型中黄10号为对照,对大豆炸荚性状进行了鉴定分析。结果表明:转基因植株阳性率T_1代为87.5%,T_2和T_3代均达到100%,说明GmAGL8基因已基本能够在转基因后代中稳定遗传。RT-q PCR检测结果显示,转基因植株中GmAGL8基因的相对表达量都明显高于非转基因植株,且各转基因植株之间表达量具有差异性。对T_1、T_2和T_3代植株炸荚率进行了统计,不同世代转基因大豆的平均炸荚率为9.09%,而非转基因大豆炸荚率为83.3%,转基因与非转基因大豆之间炸荚率存在显著差异。综上所述,GmAGL8基因已基本实现在大豆转基因后代中稳定遗传并正常表达,表型鉴定结果初步证明了GmAGL8基因与大豆炸荚性状相关。     

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.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

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.