大豆子叶节对潮霉素敏感性研究

标记基因的利用是筛选和鉴定转基因植株的有效方法,使用潮霉素能抑制植物的生长.选用3个基因型大豆为材料,以褐化率、分化率为指标,研究了不同质量浓度潮霉素对大豆子叶节分化和丛生芽生根的影响.结果表明不同基因型大豆对潮霉素的敏感性不同,潮霉素对大豆子叶节适宜筛选浓度黑农35为6 mg·L-1、合丰35和合丰25为4 mg·L-1;丛生芽生根筛选浓度黑农35为2 mg·L-1、合丰35和合丰25为1 mg·L-1.     

大豆下胚轴不定芽对卡那霉素和氯化钠耐性的研究

为探讨不同基因型大豆对卡那霉素和NaCl的耐性,以大豆黑农44、合丰35和淮豆9号的下胚轴为外植体,分别研究了不同浓度的卡那霉素和NaCl对不同基因型大豆下胚轴不定芽形成的影响.结果表明:大豆不同基因型对卡那霉素和NaCl的耐受性不同,且在伸长培养42 d时随卡那霉素和NaCl浓度的增加,不定芽诱导率、芽数和芽长均显著降低;黑农44、合丰35和淮豆9号卡那霉素的筛选浓度分别为100,150,100 mg·L-1,NaCl的筛选浓度分别为100,100,75 mmol· L-1.     

农杆菌介导不同基因型大豆品种子叶节遗传转化条件的研究

以黑农46、黑农53和黑农56的子叶节为转化受体,对农杆菌介导大豆子叶节遗传转化中的6-BA浓度、草丁膦浓度、侵染时间、共培养时间以及伸长培养基进行筛选,确定适合不同基因型的最佳转化条件。结果表明:黑农46、黑农53和黑农56的最佳6-BA诱导浓度分别为1.7、1.6和1.7 mg.L-1;最佳草丁膦筛选浓度分别为2.0、3.0和2.0 mg.L-1;同时确定了侵染时间、共培养时间和伸长培养基类型的最佳组合是侵染时间25 min、共培养时间3 d和Ⅲ型伸长培养基。     

卡那霉素和草铵膦对不同基因型大豆胚尖不定芽诱导的影响

以合丰35、黑农44和吉林35的胚尖为外植体,分别考察了不同浓度的卡那霉素和草铵膦对不同基因型大豆胚尖不定芽诱导的影响。结果表明,不定芽诱导率合丰35和吉林35在卡那霉素100 mg.L-1时与对照差异不显著,黑农44在100 mg.L-1处理时显著低于对照;芽数吉林35在卡那霉素100 mg.L-1时显著低于对照并高于其他浓度,而合丰35与黑农44在100 mg.L-1时芽数与对照差异不显著;3种基因型大豆胚尖不定芽伸长均在卡那霉素浓度为100 mg.L-1时受到显著抑制。草铵膦浓度在0.2～1.2 mg.L-1时对合丰35和吉林35的芽数没有影响,但黑农44在1.0 mg.L-1时芽数开始显著低于对照;芽长合丰35、黑农44和吉林35分别在0.6、0.2和0.2 mg.L-1时显著低于对照。因此,合丰35、黑农44和吉林35的适宜卡那霉素的筛选浓度为100 mg.L-1,草铵膦浓度分别为0.6、0.2和0.2mg.L-1。     

MYB转录因子AtPHR1转化大豆研究

以MYB转录因子AtPHR1表达载体为转化对象,采用农杆菌介导子叶节转化技术将其转入栽培大豆,研究不同萌发时间、预培养时间、菌液和侵染液浓度、大豆基因型以及筛选剂浓度对转化效率的影响.结果表明:以萌发5d大豆幼苗制备子叶节外植体,预培养1d,农杆菌菌液OD600为0.7,侵染液OD600为0.5或0.7进行转化,100 mg.L-1卡那霉素进行筛选的抗性芽诱导率最高;5个供试品种中,以五星2号的转化率最高,约为2.0％;经PCR检测转化后的大豆植株,获得了含有转录因子AtPHR1的5个大豆新材料.     

根癌农杆菌介导的大豆子叶节转化体系的优化

以13种不同基因型的大豆为材料,研究了大豆外植体再生过程中不同大豆基因型对丛生芽数目的影响,选取优势基因型为受体材料,比较了在草丁膦和潮霉素筛选压力下外植体的再生情况,并确定其合适的筛选浓度,在对农杆菌介导的子叶节转化体系优化的基础上进行了大豆转化效率的研究。结果显示:在相同的芽诱导条件下,山宁14产生的丛生芽最多,更适合于大豆子叶节转化;与其它筛选剂相比,采用潮霉素的梯度筛选更有利于抗性苗的成活,其最适筛选浓度为8 mg.L-1;通过检测GUS基因的表达和分子鉴定证明外源的GUS基因已插入到转基因植株的基因组中,转化效率达到3.2%。     

大豆新品系黑农56子叶节再生体系的优化

为获得高效的大豆再生体系,选用大豆新品系黑农56子叶节进行了组织培养的研究,确定黑农56最适的萌发培养基与芽诱导培养基激素浓度.即萌发培养基为不含6-BA的MS培养基;芽诱导培养基添加6-BA和IBA的浓度分别为2.0 mg·L-1,0.2 mg·L-1的B5培养基.并确定黑农56的草铵膦选择压力为4 mg·L-1.     

农杆菌介导的小麦成熟胚转化的影响因素

为了研究农杆菌介导的小麦成熟胚转化的影响因素,以6个小麦品种成熟胚为外植体进行离体培养,以EHA105和LBA4404农杆菌为供体(含有pCAMBIA1305双元载体)材料,研究了诱导培养基、分化培养基、农杆菌菌株、愈伤组织诱导培养时间、农杆菌菌液浓度和侵染时间对小麦成熟胚愈伤组织诱导、分化、再生的影响。结果表明:(1)以小麦品种小偃22的成熟胚为材料,获得最佳的诱导培养基方案(MS+2mg.L-1 2,4-D+0.5mg.L-1 KT+500mg.L-1水解酪蛋白+150mg.L-1天门冬酰胺)和分化培养基方案(MS+2mg.L-1 ZT+0.5mg.L-1 KT);(2)6个小麦品种中,洛阳8176和张掖春小麦具有较强的再生能力,筛选培养后较多的愈伤组织分化出小绿点;(3)洛阳8716和张掖春小麦的成熟胚,经愈伤组织诱导培养6-7d,农杆菌侵染后愈伤组织再生能力强;(4)农杆菌侵染后愈伤组织的再生能力与农杆菌菌株的关系不明显,而与小麦品种基因型、侵染时间和菌液浓度有较明显的关系;(5)以小麦洛阳8716和张掖春小麦成熟胚愈伤组织为受体,黑暗条件下诱导培养6-7d,在24±1℃黑暗条件下共培养3d和500mg.L-1羧苄青霉素(Cb)除菌及10mg.L-1潮霉素筛选处理后,共得到分化植株23株,其中以洛阳8716为受体材料,由农杆菌LBA4404和EHA105转化得到的植株分别为11株和4株,植株分化率分别为3.57%和1.31%;以张掖春小麦为受体材料,由农杆菌LBA4404和EHA105转化得到的植株分别为5株和3株,植株分化率分别为1.57%和1.14%。     

引进大豆种质遗传转化适用基因型的筛选

以引进种质"越黑"、"越褐"、Moshidou Gong503(半野生种)、日A、日B1、日B2的子叶节为受体材料,采用农杆菌介导法转入抗虫基因cryI,筛选组织培养适应性强,转化效率高的引进大豆种质。并对适宜遗传转化的基因型在萌发阶段和芽诱导阶段的适宜6-BA浓度进行筛选。结果表明:参试品种中"越褐"为适用于子叶节器官发生途径的基因型;萌发阶段添加浓度为0.1 mg.L-1的6-BA,可获得最佳轴根比,此时的无菌苗下胚轴粗壮无须根;萌发阶段和芽诱导阶段6-BA的最佳浓度分别为0.1和1.7 mg.L-1。     

硼酸诱导的大豆子叶节转化新方法

采用农杆菌介导法,以苏云金芽孢杆菌(Bacillus thuringiensis)毒性蛋白基因Bt为目的基因,研究了不同硼酸浓度处理对大豆子叶节转基因的影响.结果表明:200 mg·L-1硼酸浓度诱导培养基诱导的大豆丛生芽长势最好,而且转基因效率高达3.3%.对获得大豆转化幼苗的根和叶片采用PCR、逆转录PCR和Sou...     

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.