矮化大豆‘HK808’中3种内源激素与矮化性状形成的关系

为研究矮化大豆内源激素调控机制,通过高效液相色谱法对2种试材‘东农42’及其矮化突变体‘HK808’不同生长期内源激素GA_3、IAA及ABA含量进行测定分析。结果表明:矮化大豆茎尖及节间部GA_3含量显著低于野生型,且呈极显著差异;矮化大豆节间部IAA含量显著高于野生型,茎尖部最大差异可达43倍;矮化大豆茎尖部ABA含量显著高于野生型,节间部ABA含量除8-leaf至10-leaf外其他时期‘HK808’均与野生型呈显著差异。施用100~150 mg/L的GA_3可使其恢复野生型的株高。本研究为明确矮化大豆内源激素调控机制奠定生理学研究基础,也为矮化大豆品种的鉴定及培育提供理论依据。     

ALA和MgSO4处理对红掌光合特性及干物质积累的影响

以‘热情’红掌幼苗为试材，单独或混合喷施300 mg/L ALA和5 g/L MgSO4，研究ALA和MgSO4对幼苗光合特性及干物质积累的影响。结果表明，ALA和MgSO4无论是单独处理还是共同处理，均可显著或极显著提高红掌叶片的叶绿素含量、叶绿素a的比率、净光合速率、叶片气孔导度、胞间CO2浓度、水分利用率、瞬时羧化效率、干鲜比(干重/鲜重)以及电子传递到 QA-下游的其他电子受体的概率，降低气孔限制值。其中以ALA和MgSO4混合处理的效果最佳，该处理的叶绿素含量比对照高20.53%，净光合速率比对照提高1.58倍，差异均达极显著水平。由此可见，ALA和MgSO4混合处理能更有效提高红掌光合性能，促进干物质的积累。     

高温胁迫下黄嘌呤脱氢酶基因超表达对水稻幼苗的保护作用

【目的】黄嘌呤脱氢酶(xanthine dehydrogenase, XDH)是嘌呤代谢的关键酶。通过分析高温胁迫对OsXDH超表达转基因水稻株系幼苗叶片生理指标的影响,探究XDH缓解水稻高温胁迫的生理机制。【方法】以OsXDH超表达转基因株系(xdh1和xdh5)及受体品种日本晴(WT)为材料,研究了高温胁迫对水稻幼苗叶片叶绿素含量、相对含水量、可溶性蛋白含量、活性氧代谢、抗氧化酶活性、XDH活性及嘌呤代谢产物尿囊素(allantoin)和尿囊酸(allantoate)含量等生理指标的影响。【结果】高温胁迫处理前,超表达株系的叶绿素含量、相对含水量、可溶性蛋白含量、活性氧代谢及抗氧化酶活性等生理指标均与野生型无显著差异;高温胁迫5 d,超表达株系的叶绿素、相对含水量、可溶性蛋白含量及抗氧化酶活性均高于野生型,而过氧化氢(H₂O₂)及丙二醛(MDA)的含量显著低于野生型;适温恢复生长5 d,野生型和超表达株系的叶绿素含量、相对含水量及可溶性蛋白含量均有所提高,超表达株系均高于野生型,H₂O₂ 和MDA的含量降低,超表达株系均低于野生型;受高温诱导超表达株系与野生型中XDH酶活性及尿囊素和尿囊酸的含量均提高,且在整个处理过程中超表达转基因株系均高于野生型。【结论】XDH通过调控酰脲类物质的合成,补偿自身的抗氧化能力并增强抗氧化酶系统的活性,从而有效提高水稻幼苗对高温胁迫的耐受能力。     

大豆GmPRP转基因拟南芥抗盐性鉴定

为研究大豆脯氨酸富集蛋白基因Gm PRP在植物应对盐胁迫中的作用,利用前期克隆的Gm PRP基因,以p PZP为植物表达载体,构建了由组成型启动子Ca MV35S驱动Gm PRP基因的植物表达载体。通过Floral dip法对拟南芥进行遗传转化,获得7株阳性转基因株系。盐处理后,转基因拟南芥的种子萌发率高于野生型且叶片中丙二醛含量极显著低于野生型,表明Gm PRP提高了转基因拟南芥的抗盐性。     

大豆GmDof2.2 提高转基因烟草对盐胁迫的敏感性

Dof转录因子参与植物对非生物胁迫应答。本研究对大豆GmDof2.2进行克隆及耐盐性功能鉴定。实时荧光定量PCR结果显示GmDof2.2在大豆幼苗中可以响应非生物胁迫,GmDof2.2基因开放阅读框全长867 bp,编码288个氨基酸的蛋白,其分子量31.4 kDa,等电点10.23,蛋白质序列中含有一个保守的Dof结构域。GmDof2.2启动子区含有3种胁迫响应相关的顺式作用元件（ARE、MBS和WUN-motif）和3种激素响应相关顺式作用元件（ABRE、P-box和TCA-element）。将GmDof2.2构建植物表达载体并转化烟草,共获得4株GmDof2.2异源表达的转基因烟草株系（OE1-OE4）,OE1中GmDof2.2的表达量最高,其次为OE2。盐胁迫处理后,转基因烟草萎蔫程度高于野生型烟草,转基因烟草叶片的叶绿素、可溶性糖及脯氨酸含量均显著低于野生型烟草,而丙二醛含量则高于野生型烟草。表明GmDof2.2的异源表达提高了转基因烟草株系对盐胁迫的敏感性。本研究为大豆Dof转录因子抗逆机制研究及应用提供理论依据。     

转α-微管蛋白基因SoTUA甘蔗T2代的生理生化特性分析

本研究对已获得的转α-微管蛋白基因SoTUA的T₂代甘蔗株系进行PCR扩增及测序,从检测阳性的转基因甘蔗中选6个转基因株系（T1、T2、T3、T4、T5、T6）与非转基因野生型甘蔗对照（WT）进行了低温胁迫（4 ℃）处理,在处理0、5、10 d测定甘蔗叶片丙二醛（MDA）和渗透调节物（可溶性糖、可溶性蛋白）含量以及过氧化物酶（POD）和超氧化物歧化酶（SOD）活性,并采用RT-qPCR法分析了低温处理下甘蔗叶片α-微管蛋白基因的表达情况。结果表明：在4 ℃低温处理下,6个转SoTUA基因甘蔗与WT中α-微管蛋白的转录因子表达量随着胁迫时间的延长上调表达。胁迫后5、10 d转基因株系的相对表达量始终高于WT甘蔗,低温处理10 d时转基因T1显著高于其他株系（P<0.05）。在低温胁迫下,甘蔗的MDA含量逐渐增高,而转基因甘蔗增幅显著低于WT甘蔗,10 d时转基因株系MDA的含量比WT低41.77%（P<0.05）;POD活性在不同株系之间变化趋势不同,但转基因甘蔗POD活性显著高于WT甘蔗（P< 0.05）;转基因T1、T2、T4、T6株系的SOD活性随着胁迫天数增加呈现先增加后减少的趋势,而WT与转基因T3、T5的SOD活性逐渐升高;甘蔗的可溶性糖含量逐渐上升,转基因甘蔗的可溶性蛋白含量在0 d显著高于野生型甘蔗,胁迫后变化趋势在株系之间有所差异;转基因甘蔗SoTUA相对表达量与可溶性糖含量呈极显著的正相关。利用隶属函数综合分析评价,抗寒性排序结果为：T3>T2>T1>T5>T6>T4>WT。在低温胁迫下,转基因甘蔗SoTUA基因的上调表达能提高甘蔗的抗寒性,且具有遗传稳定性。     

转正义和反义PPase基因对马铃薯块茎休眠相关生理指标的影响

将转正、反义无机焦磷酸酶(PPase)基因马铃薯‘甘农薯2号’块茎分别贮藏于4℃和25℃下90 d,测定其PPase活性和无机Pi含量等生理生化指标。结果表明,在25℃贮藏温度下,与未转基因对照相比,转正义PPas e基因的两个株系(G-2-4和G-2-5)块茎中PPase活性、Pi与可溶性糖含量均增加,与未转基因对照相比差异显著,G-2-4的淀粉含量与未转基因对照相比显著降低。转反义PPas e基因的两个株系(G-1-1和G-1-2)PPase活性、Pi与可溶性糖含量均降低,与未转基因对照相比差异显著,G-1-2淀粉含量与未转基因对照相比极显著增加。与25℃贮藏温度相比,4℃贮藏温度下转正、反义基因株系块茎中的PPase活性、Pi、可溶性糖和淀粉含量的变化趋势与25℃贮藏温度基本一致,但其PPase活性、Pi含量和淀粉含量高于25℃贮藏温度下的转基因株系块茎,而其可溶性糖含量低于25℃贮藏温度下的转基因株系块茎含量。     

低温胁迫对蝴蝶兰光合及生理特性的影响

本研究以‘大辣椒’、‘4 号’、‘富乐夕阳’、‘火凤凰’、‘婚宴’和‘满天红’6 个蝴蝶兰品种为试材， 分析了低温胁迫过程中蝴蝶兰叶片叶绿素荧光参数的变化，并从中挑选出抗冷品种‘大辣椒’和不抗冷品种‘富乐夕 阳’，再对这 2 个品种的叶绿素含量、渗透调节物质、光合酶 PEPC 及抗氧化酶活性进行测定。结果表明：低温胁迫 期间，蝴蝶兰叶片的叶绿素荧光参数 Fo 逐渐升高，其他均呈降低趋势，低温处理后期，‘大辣椒’的 Fv/Fm 最高，‘大 辣椒’的叶绿素含量高于‘富乐夕阳’；PEPC 活性先逐渐升高，后趋于平缓，‘大辣椒’PEPC 活性显著高于‘富乐 夕阳’；可溶性糖、可溶性蛋白含量先升后降，‘大辣椒’的积累量高于‘富乐夕阳’；脯氨酸含量变化规律不一致； SOD 活性均逐渐升高，而过氧化物酶 POD、过氧化氢酶 CAT、抗坏血酸过氧化物酶 APX 活性基本呈先升后降的趋势， ‘大辣椒’各抗氧化物酶活性升高幅度均大于‘富乐夕阳’。由结果可知，‘大辣椒’PEPC 和 SOD 活性显著高于‘富 乐夕阳’，可能是其抗冷性较强的重要原因。研究结果为蝴蝶兰抗冷品种的选育及抗性分子机理研究提供理论基础。     

利用“微创刷”法获得抗草甘膦转基因大豆

以发芽3 d的大豆成熟种子胚尖生长点为作用点,利用"微创刷"法将抗草甘膦基因(EPSPS)转入绥农22中,对转化植株T1代进行草甘膦筛选,对筛选后的抗性植株进行PCR检测,得到抗草甘膦转基因大豆。同时研究了不同浓度草甘膦对野生型绥农22与抗草甘膦转基因绥农22大豆植株的影响。结果表明:绥农22 T0代成株率为97.38%,对T1代具有草甘膦抗性的植株进行PCR检测,初步证明EPSPS基因成功转入大豆中,T1代转化效率为6.20%;对野生型绥农22与"微创刷"法获得的转基因绥农22大豆在不同浓度草甘膦进行相关生理指标测定,抗草甘膦转基因绥农22大豆在不同浓度草甘膦作用下叶片叶绿素含量指数、光合速率高于野生型绥农22大豆,莽草酸含量低于野生型绥农22大豆,进一步证明了大豆抗性植株对草甘膦的抗性。     

大豆转录因子GmNAC8的克隆及耐旱性功能分析

大豆转录因子GmNAC8在耐旱材料和敏感材料中明显差异表达,该基因CDS序列全长1 092bp,编码363个氨基酸残基。通过软件预测,蛋白质相对分子质量为41.82k D,等电点为8.51,其N-端含有42aa组成的NAC保守结构域,C-端高度变异。进化树分析表明,该蛋白与菜豆、红豆、绿豆同源关系最近。在洋葱表皮细胞中的亚细胞定位分析表明GmNAC8蛋白定位于细胞核。转录水平表达分析表明,GmNAC8基因在转基因株系叶中的表达量要明显高于根中的表达量;GmNAC8基因受0.1mmol/L IAA和ABA诱导表达量显著上升,受GA和SA抑制。GmNAC8基因在拟南芥中超量表达可以使拟南芥叶片更绿,耐旱能力增强。抗旱生理指标检测表明,在干旱处理10d后,转基因拟南芥叶中蛋白质含量、脯氨酸含量、POD活性均高于野生型拟南芥,丙二醛含量明显低于野生型拟南芥,仅为42%。本研究结果为进一步研究GmNAC8在植物耐旱反应中的分子机理奠定基础。     

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).