海马齿对不同比例淡海水组培的生长和生理响应

以红树林伴生植物海马齿为研究对象,通过水培试验系统考察了海马齿植株在不同淡海水组合培养条件下的生长和生理变化,以探讨海马齿植株盐环境的适应性和耐盐机制.结果显示,随着培养液中海水比例增加,海马齿植株生长速度变慢,节间变短,叶片肉质化程度加重,但都能健康生长并完成其固有的生长周期.随着培养液中海水比例的增加,海马齿植株叶片叶绿素含量、蛋白质含量以及节间长度均呈下降趋势,可溶性糖、脯氨酸含量和茎周长却逐渐增加,叶片水分含量和根系活力先升高后降低,而叶片干物质和丙二醛含量则呈先降低后升高趋势.2∶1淡/海水组合培养液中海马齿植株的长势最好,根系活力最强.研究结果表明,海马齿植株最适宜在一定比例的淡/海水培养液中或一定盐浓度环境下生长,其具有很强的耐盐碱特性,渗透调节是其适应外界盐胁迫的机制之一.     

铅胁迫对大灰藓几种生理指标的影响

苔藓植物是对环境最为敏感的指示植物之一。灰藓属（Hypnum）植物被广泛用于监测环境污染。为了更好地了解藓类植物对重金属的胁迫反应,测定了不同Pb浓度胁迫下大灰藓总叶绿素含量、丙二醛、脯氨酸和可溶性糖生理指标,并对4种生理指标与铅浓度之间进行了拟合。研究结果显示,在低浓度Pb（〈0.01mmol/L）胁迫下,总叶绿素含量升高。当Pb浓度≥1mmol/L时,总叶绿素含量下降。而丙二醛、脯氨酸及可溶性糖含量则在低Pb浓度（≤0.1mmol/L）下增加不明显,在较高Pb浓度（≥1mmol/L）下均有明显的升高,表现出对铅胁迫的适应性反应。4种生理指标与铅胁迫浓度之间表现出较好的剂量-效应关系。     

Pb胁迫条件下狭叶香蒲种子的萌发特性及其幼苗的生理响应

对0、30、150、300、450和600μmol·L-1Pb胁迫条件下狭叶香蒲（TyphaangustifoliaLinn.）种子的萌发特性进行了研究,并分析了0、450、900、1800和2700μmol·L-1Pb胁迫对狭叶香蒲幼苗叶片及根系中部分生理生化指标的影响。结果表明：随Pb浓度提高,狭叶香蒲种子的发芽率、发芽势、发芽指数和活力指数以及下胚轴长度均逐渐下降且低于对照,而其下胚轴长度抑制指数则逐渐增大,但在30μmol·L-1Pb胁迫条件下各项萌发指标均与对照无显著差异。叶片叶绿素a、叶绿素b及总叶绿素含量随Pb浓度提高呈逐渐下降趋势,但在450和900μmol·L-1Pb胁迫条件下与对照无显著差异,而在1800和2700μmol·L-1Pb胁迫条件下显著低于对照。在Pb胁迫条件下叶片和根中SOD活性均显著高于对照但变化趋势不同;随Pb浓度提高,叶片SOD活性呈波动但整体上升的趋势,而根中SOD活性则呈逐渐降低的趋势。叶片和根中POD活性均随Pb浓度提高呈持续上升的趋势,其中,在450和900μmol·L-1Pb胁迫条件下叶片的POD活性低于对照、根的POD活性高于对照,但均与对照无显著差异;而在1800和2700μmol·L-1Pb胁迫条件下叶片和根的POD活性均显著高于对照。在Pb胁迫条件下叶片和根中AsA和MDA含量均高于对照。随Pb浓度提高,叶片的AsA含量总体上逐渐增加但在450和900μmol·L-1Pb胁迫条件下与对照无显著差异;而根的AsA含量则呈先增加后降低的趋势且均与对照差异显著。随Pb浓度提高,叶片的MDA含量先增后降但均与对照无显著差异;而根的MDA含量呈“高-低-高”的波动趋势且仅在450μmol·L-1Pb胁迫条件下与对照差异显著。综合分析结果显示：狭叶香蒲幼苗根系对Pb胁迫的敏感性可能强于叶片;狭叶香蒲种子可在轻度Pb污染水体中萌发和生长;其幼苗对Pb胁迫具有一定的耐性,可用于中度Pb污染水体的修复。     

海马齿对无机汞的耐性和吸附积累

报道了海马齿(Sesuvium portulacastrum)对重金属汞的耐性和吸附特性。 在10 μmol·L^-1汞胁迫时, 海马齿中脯氨酸含量明显低于对照; 丙二醛(MDA)含量、根的电解质外渗率(Electrolyte leakage rate, ELR)无明显变化; 叶绿素含量增加; 植物生长良好, 形态、生长速率、鲜重和根的长度与对照无区别, 且有新的须根形成。结果表明: 低浓度汞对海马齿的生长发育起着促进作用。海马齿能大量吸附积累汞离子, 主要积累在根组织中。当培养液中汞浓度为50 μmol·L^-1时, 海马齿根中汞含量最高可达到33.9 μg·g^-1DW, 是相同处理下地上部分的70倍。培养液中汞浓度为10 μmol·L^-1时, 植物并未受到伤害, 且能快速生长, 此时根部的汞含量可达到12.02 μg·g^-1 DW。由此可见, 海马齿植物表现为很强的耐汞和吸收汞特性。     

复合重金属胁迫对两种藓类植物生理特性的影响

研究混合金属离子(Zn2+,Cu2+,Pb2+和Cd2+)溶液对东亚砂藓(Racomitrium japonicum)和拟垂枝藓(Rhytidiadelphus squarrosus)的膜系统、光合系统的损伤情况及其抗氧化酶系统的变化。结果表明:随着处理重金属浓度的增加,两种藓类植物体中的游离脯氨酸含量先降后升高再下降;丙二醛含量具应激效应;SOD、POD和CAT活性在低浓度下升高(东亚砂藓≤50μmol.L-1,拟垂枝藓≤30μmol.L-1)。在高浓度下降低(东亚砂藓50μmo.lL-1,拟垂枝藓30μmol.L-1);可溶性蛋白含量在东亚砂藓中表现为降低-升高-降低,而拟垂枝藓先升后降;叶绿素含量呈抑制效应。拟垂枝藓的生理变化较东亚砂藓明显,更有利于检测重金属的污染。     

盐胁迫对盆栽滁菊生理特性的影响

以滁菊扦插苗为材料,采用不同盐浓度进行盆栽实验,研究了在不同 NaCl 浓度(0、100、200、300、400、500 mmol·L-1)下,滁菊的形态及叶绿素含量、可溶性糖含量、脯氨酸含量、MDA 含量、叶片伤害率和根系活力等生理指标的变化情况。结果表明：叶绿素含量、根系活力随盐胁迫强度的增强而下降;可溶性糖和MDA 含量随盐胁迫强度的增强呈先升后降趋势;叶片伤害率、脯氨酸含量随盐胁迫强度的增强而增加。研究发现滁菊扦插苗能耐受较低浓度的盐胁迫,当盐浓度较高时,其生长受到较大抑制。     

CO_2浓度和温度对甘肃风毛菊生理特性的协同影响

该研究以分布在青藏高原东缘的特有种菊科风毛菊属植物甘肃风毛菊为材料,利用CO_2人工气候箱模拟CO_2浓度升高和温度变化,分析其对甘肃风毛菊各项生理指标的影响。结果表明:CO_2浓度和温度升高对甘肃风毛菊的生理指标影响显著,存在显著的交互作用。在CO_2浓度为550μmol·mol~(-1)时,甘肃风毛菊叶片叶绿素总量、可溶性糖和可溶性蛋白含量达到最大值,而丙二醛(MDA)和超氧阴离子自由基含量均为最小值;在较高温度下,甘肃风毛菊叶片叶绿素总量、可溶性糖和可溶性蛋白含量均增加;丙二醛(MDA)和超氧阴离子自由基含量均降低。当CO_2浓度为550μmol·mol~(-1)时,升高温度能显著提高甘肃风毛菊叶片的叶绿素总量、可溶性糖和可溶性蛋白含量,并且显著减少丙二醛(MDA)和超氧阴离子自由基含量。该研究表明CO_2浓度和温度的升高对甘肃风毛菊的生长具有一定的促进作用。     

干旱胁迫下叶面喷施褪黑素对滁菊幼苗生理生化特性的影响

以滁菊品种"金玉"幼苗为材料,通过日光温室内盆栽实验,在中度干旱胁迫条件下(土壤田间持水量的40%),研究叶面喷施外源褪黑素(MT,100μmol·L-1)对滁菊幼苗生长及生理生化特性的影响,探讨提高滁菊耐干旱性的新途径。结果表明:(1)与对照相比,干旱胁迫处理降低了滁菊叶片叶绿素含量、净光合速率和水分利用效率,提高了可溶性蛋白质、可溶性糖和脯氨酸含量,而叶片MDA含量和相对电导率显著增加,显著抑制了滁菊幼苗的生长。(2)在干旱胁迫条件下,外源MT可显著提高滁菊幼苗叶片脯氨酸、可溶性蛋白质和可溶性糖的含量,并显著降低了叶片相对电导率和MDA含量,使幼苗保持较高叶绿素含量和净光合速率。(3)与干旱胁迫处理相比,外源MT处理的滁菊地上部和根系干重、鲜重均显著增加。研究发现,外源褪黑素(MT)在一定程度上可通过促进滁菊幼苗渗透调节物质的积累,有效降低干旱胁迫对其细胞膜的伤害,维持其正常的细胞膜功能,保持其较高的光合速率和水分利用效率,从而增加其对干旱环境的适应性。     

NaCl胁迫对'金光'杏梅幼苗生长及其生理指标的影响

以‘金光’杏梅盆栽幼苗为试验材料,研究了NaCl胁迫对‘金光’杏梅幼苗生长和生理指标的影响.结果表明:NaCl胁迫显著抑制了‘金光’杏梅幼苗的生长,随着NaCl浓度的升高,‘金光’杏梅的株高、叶面积、叶鲜重、叶干重、茎干重、根干重、叶绿素含量和净光合速率均呈下降趋势;叶片细胞膜透性、丙二醛(MDA)、可溶性糖、脯氨酸(Pro)含量以及POD活性显著增加;而SOD活性在低NaCl浓度下上升,在高NaCl浓度下下降.     

独脚金内酯类似物GR24对山定子幼苗低氮胁迫的缓解作用

研究叶面喷施不同浓度独脚金内酯类似物GR24(0、1、5、10、20μmol·L^-1)对低氮胁迫下山定子幼苗叶片光合生理特性及根系活性氧代谢和氮同化的影响，以期探索应用GR24缓解山定子幼苗低氮胁迫的适宜方法。结果表明：低氮胁迫下山定子幼苗地上部生物量显著降低，根冠比升高；叶片中叶绿素含量降低，类胡萝卜素含量升高，光合活性降低；根系中超氧化物歧化酶和过氧化氢酶活性变化不显著，但过氧化物酶和抗坏血酸过氧化物酶活性及可溶性糖、游离脯氨酸和活性氧含量显著升高，可溶性蛋白含量显著降低；根系中硝酸根离子含量降低，铵根离子含量升高，硝酸还原酶和谷氨酸合成酶活性均降低。与不喷施GR24相比，低氮胁迫和正常供氮条件下叶面喷施10和20μmol·L^-1 GR24处理都不同程度增加了山定子幼苗生物量和根冠比，提高了叶绿素含量，增强了净光合速率、蒸腾速率和气孔导度等光合参数，改善了PSⅡ最大光化学效率和单位面积电子传递量子产额等荧光特性，增加了根系渗透调节物质(可溶性蛋白、可溶性糖和游离脯氨酸)含量，增强了根系谷氨酰胺合成酶活性；低氮胁迫下叶面喷施10和20μmo...     

Y-chromosome Data and Tribal Affiliations of Allenopithecus and Miopithecus

The phylogeny of Old World monkeys has remained unresolved in part because of a lack of resolution in the Cercopithecinae. Competing morphological hypotheses have had Allen's swamp monkey (Allenopithecus nigroviridis) and the talapoins (Miopithecus spp.) as basal branches of either the tribe Cercopithecini or the tribe Papionini. Previous molecular analyses have not adequately addressed the issue. To better understand the evolutionary history of these primates, we sequenced and subjected to phylogenetic analysis 3.1 kb of 2 loci (TSPY and SRY) from the non-recombining portion of the Y-chromosome. Individuals from the genera Allenopithecus, Miopithecus, Erythrocebus, Chlorocebus, and Cercopithecus were surveyed and their sequences compared with those previously published for the Papionini and Colobinae. The results suggest Allenopithecus and Miopithecus are more closely related to the Cercopithecini than Papionini. Our data also support the hypothesis that within the Cercopithecini, Erythrocebus and Chlorocebus share a close evolutionary relationship, distinct from the other members of the tribe.     

Identification of novel oocyte and granulosa cell markers

Here we present novel gene expression patterns in the ovary as part of an ongoing assessment of published micro-array data from mouse oocytes and embryos. We present the expression patterns of 13 genes that had been determined by micro-array to be expressed in the mature egg, but not during subsequent preimplantation development. In-situ hybridization of sectioned ovaries revealed that these genes were expressed in one of two distinct patterns: (1) oocyte-specific or (2) expressed in both the oocyte and surrounding granulosa cells. Despite the fact that micro-array data demonstrated expression in the egg, several of these genes are expressed at low levels in the oocyte, but strongly expressed in granulosa cells. Eleven of these genes have no reported function or expression during oogenesis, indicating that this approach is a necessary step towards functional annotation of the genome. Also of note is that while some of these gene products have been well characterized in other tissues and cell types, others are relatively unstudied in the literature. Our results provide novel gene expression information that may provide insights into the molecular mechanisms of follicular recruitment, oocyte maturation and ovulation and will direct further experimentation into the role these genes play during oogenesis.     

Nystatin and killer toxin sensitivity of free and immobilizedSaccharomyces cerevisiae

The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.     

The hernandez and fernandez genes of Drosophila specify eye and antenna

The formation of different structures in Drosophila depends on the combined activities of selector genes and signaling pathways. For instance, the antenna requires the selector gene homothorax, which distinguishes between the leg and the antenna and can specify distal antenna if expressed ectopically. Similarly, the eye is formed by a group of "eye-specifying" genes, among them eyeless, which can direct eye development ectopically. We report here the characterization of the hernandez and fernandez genes, expressed in the antennal and eye primordia of the eye-antenna imaginal disc. The predicted proteins encoded by these two genes have 27% common amino acids and include a Pipsqueak domain. Reduced expression of either hernandez or fernandez mildly affects antenna and eye development, while the inactivation of both genes partially transforms distal antenna into leg. Ectopic expression of either of the two genes results in two different phenotypes: it can form distal antenna, activating genes like homothorax, spineless, and spalt, and it can promote eye development and activates eyeless. Reciprocally, eyeless can induce hernandez and fernandez expression, and homothorax and spineless can activate both hernandez and fernandez when ectopically expressed. The formation of eye by these genes seems to require Notch signaling, since the induction of ectopic eyes and the activation of eyeless by the hernandez gene are suppressed when the Notch function is compromised. Our results show that the hernandez and fernandez genes are required for antennal and eye development and are also able to specify eye or antenna ectopically.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (1–3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC₅₀'s 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC₅₀'s 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).     

Lysine Dendrimers and Their Starburst Polymer Derivatives: Possible Application for DNA Compaction and in vitro Delivery of Genetic Constructs

We attempted to find some compounds for the effective delivery of gene constructs into cells and obtained two trispherical dendrimers on the basis of lysine, (Lys)₈-(,-Lys)₄-(,-Lys)₂-(,-Lys)-Ala-NH₂ (D1) and ((Lys)₈-(,-Lys)₄-(,-Lys)₂-,-Lys)-Ala-[Lys(Plm)]₂-Ala-NH₂ (D2), as well as the starburst polymeric derivatives of D1, (pVIm) ₈ -D1 and (pLys) _n -D1, containing poly(N-vinylimidazole) and polylysine chains single-point bound to the dendrimer amino groups. The conditions of dendrimer–plasmid DNA complex formation were studied. The intracellular localization of these complexes and the expression of gene constructs delivered with their help were analyzed in transfection experiments on the HeLa cell cultures of human epithelial carcinoma and on mouse C2C12 myoblasts. It was found that the chemical structure of dendrimer D1 and its derivatives significantly affected the structure and properties of complex.     

Effects of carbon concentration and carbon to nitrogen ratio on the growth and sporulation of several biocontrol fungi

Effects of carbon concentration and carbon to nitrogen (C:N) ratio on six biocontrol fungal strains are reported in this paper. All fungal strains had extensive growth on the media supplemented with 6–12 g l⁻¹ carbon and C:N ratios from 10:1 to 80:1, and differed in nutrient requirements for sporulation. Except for the two strains of Paecilomyces lilacinus, all selected fungi attained the highest spore yields at a C:N ratio of 160:1 when the carbon concentration was 12 g l⁻¹ for Metarhizium anisopliae SQZ-1-21, 6 g l⁻¹ for M. anisopliae RS-4-1 and Trichoderma viride TV-1, and 8 g l⁻¹ for Lecanicillium lecanii CA-1-G. The optimal conditions for P. lilacinus sporulation were 8 g l⁻¹ carbon with a C:N ratio of 10:1 for M-14 and 12 g l⁻¹ carbon with a C:N ratio of 20:1 for IPC-P, respectively. The results indicated that the influence of carbon concentration and C:N ratio on fungal growth and sporulation is strain dependent; therefore, consideration for the complexity of nutrient requirements is essential for improving yields of fungal biocontrol agents.     

Pericarp structure and phylogeny of theLamiaceae-Verbenaceae-complex

Pericarp structure was investigated in 158 species of the familiesLamiaceae andVerbenaceae. Data from 221 out of 262 genera ofLamiaceae s.l. and a few ofVerbenaceae s.str. were collected in a table. A cladistic analysis was performed on the basis of pericarp characters only. The abandonment of subfam.Pogostemonoideae as a taxonomic unit is considered. Examples of groups given additional support by similarities in pericarp characters are: (1) the gynobasic-styled labiates (subfamiliesPogostemonoideae, Lamioideae, Nepetoideae); (2) aLamioideae-Pogostemonoideae-group; (3)Nepetoideae; (4) aWestringia-Hemigenia-Hemiandra-Microcorys group (in subfam.Chloranthoideae); (5) aLepechinia-Chaunostoma-group (inNepetoideae); (6) aPrunella-Cleonia-group (inNepetoideae).     

甘菊ClHSP70与ClHSP90基因的克隆及表达分析

该研究以甘菊(Chrysanthemum lavandulifolium)为实验材料,通过RT-PCR方法从甘菊转录组数据中分离出热激蛋白合成相关基因,命名为ClHSP70和ClHSP90。序列分析表明,ClHSP70基因ORF全长为2 559bp,编码852个氨基酸,蛋白功能区预测表明含有典型的HSP70蛋白NBD和SBD保守结构域;ClHSP90基因ORF全长为2 094bp,编码697个氨基酸,含有HATPase结构域和HSP90保守结构域。生物信息学分析表明,甘菊ClHSP70与大豆(Glycine max)和烟草(Nicotiana tomentosiformis)HSP70蛋白有较高的一致性,ClHSP90基因编码的氨基酸序列与紫茎泽兰(Ageratina adenophora)HSP90高度相似;实时荧光定量表达分析表明,在42℃处理不同时间,甘菊叶片中ClHSP70和ClHSP90基因表达均在0.5h时显著增加,1h达到最大值,2h后缓慢下降;不同组织表达分析表明,甘菊在42℃处理1h后,ClHSP70在成熟叶中的表达量显著高于嫩叶和根等其他组织;ClHSP90在成熟茎中的表达量最高。研究说明,ClHSP70和ClHSP90基因具有热激蛋白特征,参与了甘菊热胁迫应答过程,该研究结果为以后深入研究其基因功能奠定了基础。