木薯试管块根诱导技术研究

以木薯主栽品种‘华南205’组培苗为材料,利用正交实验设计L9(34)分析蔗糖浓度、萘乙酸(NAA)、多效唑(PP333)和茉莉酸甲酯(Me JA)对木薯试管块根诱导的影响,筛选适宜木薯试管块根诱导的培养基配方,并对较优配方组合进行验证试验和根系内淀粉粒观察。结果表明:木薯试管块根诱导较优的配方为1/2 MS+6-BA0.02 mg/L+0.1 mg/L PP_(333)+0.02 mg/L NAA+10μmol/L Me JA+50 g/L蔗糖+6.3 g/L琼脂。在该配方诱导条件下,组培苗生根率达80%以上,组培苗形成的根系增粗明显,块根内有丰富的淀粉颗粒形成。PP_(333)在木薯试管块根诱导和增粗中起着重要作用。本研究成功获得了较优的木薯试管块根诱导培养基配方,为木薯块根发生发育机理和育种研究奠定了基础。     

茶树硝态氮转运蛋白NRT1.1基因的克隆及表达分析

以茶树(Camellia sinensis(L.))品种龙井43为试材,采用PCR结合RACE技术,克隆得到硝态氮转运蛋白基因(NRT1.1)的c DNA全长序列,基因序列全长1 880 bp,其中开放阅读框(ORF)1 788 bp,编码595个氨基酸,预测蛋白质分子量为65.9 k D,理论等电点为8.99,命名为Cs NRT1.1。序列分析表明,Cs NRT1.1与葡萄NRT1.1氨基酸序列的相似性最高。通过生物信息学分析,对Cs NRT1.1的氨基酸理化性质、亲/疏水性、跨膜区域及亚细胞定位进行了预测。实时定量PCR表达分析表明,茶树根和叶片中Cs NRT1.1在1 mol·L~(-1) NO3-处理5 min内均受到抑制,叶部Cs NRT1.1表达量0.5 h后即达到最大值,24 h内各个时间点均高于根部,根中表达量Cs NRT1.1始终低于对照。本研究结果为研究茶树对NO3-的吸收、转运和调控机理提供了分子生物学基础。     

苎麻BnNRT1.1基因的克隆及表达特性研究

硝酸盐转运蛋白1.1(nitrate transporter 1.1,NRT1.1)在植物对硝酸盐的吸收与利用过程中具有非常重要的作用,明确其对苎麻的作用机制,可有助于提高苎麻的氮素利用率。研究通过克隆得到苎麻Bn NRT1.1基因的全长c DNA序列,共1869 bp,其中开放阅读框(ORF)1776 bp,编码591个氨基酸。生物信息学分析结果表明,苎麻Bn NRT1.1基因编码的蛋白质分子量为65.25 k D,等电点为8.85,为疏水性蛋白,具有12个跨膜结构域和15个磷酸化位点,在信号转导与氮素转运等代谢途径中具有重要功能。系统进化分析表明苎麻Bn NRT1.1基因与樱桃、白梨、桑树等NRT1基因具有同源关系。组织特异性表达分析发现,Bn NRT1.1主要在苎麻根中表达,而在茎、叶中的表达量相对较低;硝酸盐诱导处理发现,Bn NRT1.1在苎麻氮高效品种龙潭大麻中的表达量高于氮低效品种青皮杆麻,并且诱导处理3 d后不同品种中Bn NRT1.1表达量均达到最大值。该研究结果为苎麻对硝酸盐的吸收、转运和调控提供了分子生物学基础,旨在提高苎麻的氮素利用率。     

铁皮石斛HDR基因克隆及真菌诱导子对其表达和生物碱含量的影响

以铁皮石斛原球茎为材料,采用同源克隆的方法,成功得到了铁皮石斛Do-HDR基因的全长,并通过q PCR对其相对表达量进行分析。结果表明:Do-HDR基因全长1 784 bp(Gen Bank登录号KJ946381),5′UTR为40 bp,3′UTR为361 bp,开放阅读框为1 382 bp,编码460个氨基酸。生物信息学分析结果表明,该基因编码的蛋白为稳定的亲水蛋白,不具有跨膜结构,不含信号肽,定位于内质网。采用灭活的尖孢镰刀菌菌液作为诱导子,分别以0、100、200、500、1 000 mg/L的浓度培养3 d后测定总生物碱含量,结果表明,总生物碱含量呈现先上升后下降的趋势;当诱导子浓度为200 mg/L时,总生物碱含量达到最大值。在此基础上通过q PCR分析Do-HDR基因的相对表达量,结果发现Do-HDR基因相对表达量在诱导子浓度为200 mg/L时也到达最大值。因此,推测Do-HDR基因与生物碱的合成与积累有关。     

小麦幼苗叶片中硝酸盐转运蛋白NRT1和NRT2家族基因对氮饥饿响应的表达分析

硝酸盐转运蛋白NRT1(Nitrate transporter 1)和NRT2(Nitrate transporter 2)家族基因在高等植物氮转运过程中发挥着重要作用。为探讨NRT1和NRT2家族基因在小麦幼苗响应氮饥饿中的作用,本研究测定了氮饥饿处理过程中小麦幼苗的生长参数和叶片中叶绿素、可溶性蛋白、硝酸盐和丙二醛(MDA)的含量,并利用荧光实时定量PCR(qPCR)技术分析了叶片中NRT1(7个)和NRT2(5个)家族基因的转录水平。结果表明,氮饥饿明显抑制小麦幼苗生长,其株高、干鲜重显著下降,叶片叶绿素含量、蛋白质含量和硝酸盐含量均显著降低,而MDA含量却显著升高。在氮饥饿处理后所有测定时间点(2d、4d、6d和8d),小麦幼苗叶片中TaNRT1.1、TaNRT1.2、TaNRT1.7、TaNRT2.3和TaNRT2.4的表达均受到显著抑制;然而,氮饥饿2d时,TaNRT1.4、TaNRT1.8和TaNRT2.1的表达量显著升高;氮饥饿4d时,TaNRT1.3、TaNRT1.5和TaNRT2.5的表达量也显著升高,推测TaNRT1.3、TaNRT1.4、TaNRT1.5、TaNRT1.8、TaNRT2.1和TaNRT2.5可能在小麦幼苗响应氮饥饿中发挥着重要作用。     

除草剂Basta对11个木薯品种(品系)组培苗生长的影响

以11个木薯品种(品系)组培苗的单芽茎段为组培材料,研究在培养基中添加不同浓度除草剂Basta对木薯组培苗发根、茎伸长和存活率的影响.结果表明:随着Basta浓度的升高,木薯发根数、生长量和存活率均表现出不同程度的下降;在浓度为0.9 mg/L时,华南124的发根数为1.06条/株,株高为1.3 cm,存活率为74％,均显著高于其他品种(系),表现出优于其他品种(品系)的耐Basta能力;Basta对国内几个常见木薯品种(品系)组培苗筛选浓度为0.6～0.9 mg/L.     

木薯苹果酸脱氢酶基因克隆和表达分析

为从木薯块根中获得苹果酸脱氢酶(MDH)基因,并研究其在转录水平的表达变化规律,利用RACE技术从木薯“华南8号”块根中克隆得到了苹果酸脱氢酶基因,其cDNA全长1 175 bp,包含999 bp的开放阅读框,共编码332个氨基酸.从木薯“华南8号”中获得的MDH氨基酸序列,与其它物种的该序列相似度达84％～94％,包含细胞质苹果酸脱氢酶中高度保守的NAD结合基元“TGAAGQI”和催化基元“IWGNH”.木薯MDH基因与块根淀粉合成相关,在块根发育前期表达量较低,膨大期表达量较高,膨大后期表达量逐渐降低.     

茶树硝酸根转运蛋白基因NRT2.5的克隆及表达分析

通过RACE克隆从茶树[Camellia sinensis (L.)]叶片中获得NRT2.5基因cDNA全长序列。所得基因序列全长为2 457 bp,其中开放阅读框为1 362 bp,编码454个氨基酸,推测蛋白分子量为48.7 kD,理论等电点为9.63。生物信息学分析表明,该基因与可可树、拟南芥等的NRT2.5基因具有高度同源性,且其编码的蛋白质具有NRT家族共有的结构特征。实时定量PCR分析表明,NRT2.5基因在茶树不同组织中均有表达,但主要在成熟叶和根中表达;不同氮浓度处理后,茶树NRT2.5基因在低浓度下的表达量高于高浓度下。     

水稻纹枯病菌RsPhm基因的克隆及其表达分析

【目的】为了阐明苯酚2-单加氧酶基因(Rs Phm)在水稻纹枯病菌(Rhizoctonia solani AG-1ⅠA)黑化中的功能,【方法】采用常规PCR和RT-PCR技术对该基因进行克隆和生物信息学分析,通过荧光定量PCR(q RT-PCR)技术检测在儿茶酚胁迫下该基因的相对表达量。【结果】生物信息学分析结果表明,Rs Phm基因的DNA和c DNA全长序列分别为2 628 bp和1 983 bp,编码660个氨基酸。系统进化树分析显示,Rs Phm基因在立枯丝核菌(R.solani)不同融合群中具有较近的亲缘关系,在不同真菌之间在进化上具有一定保守性。通过q RT-PCR技术分析了在不同浓度儿茶酚胁迫下水稻纹枯病菌Rs Phm基因的转录表达情况。外源儿茶酚能提高Rs Phm基因的表达量,在12.5μg/m L浓度下表达量最高,极显著上调35.7倍,在25μg/m L和50μg/m L浓度下表达量分别上调19.1倍和28.4倍,但在100μg/m L浓度下表达量仅上调2.1倍。【结论】获得了Rs Phm基因全长序列,了解了其基本生物学信息,明确了其在儿茶酚胁迫下的表达模式。研究结果为科学、系统地阐明水稻纹枯病菌Rs Phm基因调控黑色素形成机制奠定了理论基础。     

大豆胞囊线虫热激蛋白基因Hsp70的克隆与原核表达

采用RT-PCR技术结合基因组步移技术,从大豆胞囊线虫(Heterodera glycines)中克隆了热激蛋白70基因(Hsp70)的全长cDNA序列(Hg-Hsp-70),全长1 953 bp,GenBank登录号为FJ816100.1。碱基序列分析结果表明,该序列含有9个外显子与8个内含子,与其它线虫具有较高的同源性。氨基酸序列分析表明,该基因编码650个氨基酸,相对分子量为70.7 kD,具有2个Hsp70基因家族的签名序列,与其它线虫的该基因氨基酸序列具有很高的同源性。构建了原核表达载体Hsp70pEASY-E1,采用IPTG诱导蛋白表达,SDS-PAGE电泳结果表明,当IPTG终浓度为0.2～1.2 mmol.L-1时均能显著诱导表达;以终浓度0.8 mmol.L-1的IPTG诱导5 h蛋白表达量达到最大值。     

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.     

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.     

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.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

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.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

---

Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

---

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.