扁穗牛鞭草水培无性苗构件组成特点的研究

在水培条件下,测定扁穗牛鞭草茎节形成无性苗的构件组成,结果说明:牛鞭草茎节具有无性繁殖能力,自身贮存营养可满足形成构件完整植株的需求;茎节长度与无性苗构件组成和生物量关系不大;无性苗构件间存在着差异,叶片数、叶干重、茎长度和茎干重的变异系数分别为15.08%、28.95%、22.34%、23.37%,根数、根系长、根干重的变异系数分别为45.75%、26.14%、52.86%;无性苗构件间存在着相关性,茎长度与叶片数和叶干重表现为极显著正相关(P<0.01),茎长度与根数和茎干重与根干重表现为显著正相关(P<0.05),叶干重与茎长度、叶片数、根数、根干重都表现为极显著正相关,再生生物量与叶干重为显著正相关,与茎干重、根干重为极显著正相关,根、茎、叶干重之间表现为正相关,说明无性苗地上、地下各构件生长发育是相互协调的,构件间营养分配是均衡的,从而保证了无性苗构件平衡和株型完善。     

毛乌素沙地3种典型灌木生物量分配与土壤含水量特征

灌木生物量是评价植被生产力的一个重要参数,研究不同灌木类型的生物量分配规律对指导荒漠生态系统的植被恢复具有重要科学意义。以毛乌素沙地柠条锦鸡儿、油蒿、杨柴3种典型灌木为研究对象,分析了不同灌木的生物量分配与土壤含水量特征。结果表明,3种灌木标准株整株生物量与各器官生物量均为柠条锦鸡儿﹥油蒿﹥杨柴,且均达到了显著性差异(P0.05);在根、茎、叶生物量分配及其比例方面,3种沙生灌木均表现为茎﹥根﹥叶,但各器官分配比例具有明显的差异。在植物含水率方面,杨柴和柠条锦鸡儿两种灌木各器官含水率表现为叶﹥根﹥茎,而油蒿则表现为根﹥茎﹥叶。3种灌木除叶片外(R2=0.45),整株(R2=0.74)和根(R2=0.66)的含水率均与土壤含水量存在着显著的正相关性(P0.05),而茎(R2=0.86)的含水率与土壤含水量之间达到了极显著正相关(P0.01)。3种沙生灌木在形态结构和水分调节利用方面均采取不同的方式来适应干旱生境,但其长效作用机制有待进一步研究。     

黄檗中生物碱含量的高效液相色谱分析

建立了一种简便、快速、准确的测定黄檗(Phellodendron amurense Rupr.)中生物碱含量的高效液相色谱分析方法.色谱条件:采用日本KYA HIQ sil C 18柱(250 mm×4.6 mm,5 μm),流动相乙腈/水溶液(1 000 mL溶液中含磷酸二氢钾3.4 g及十二烷基磺酸钠1.7 g)1∶1,流速1.0 mL/min,检测波长345 nm,进样量10 μL.样品制备以63 %的乙醇作溶剂,在41 ℃下超声波提取黄檗茎皮64 min.用HPLC分别测定了黄檗根皮、茎皮和叶中小檗碱、掌叶防己碱、药根碱的含量,结果表明:小檗碱和药根碱在根皮中的含量最高,茎皮次之,叶最低,而掌叶防己碱在茎皮中的含量最高,根皮次之,叶最低.     

不同地理种源麻栎苗期变异和初步选择

利用13个省(区)的36个种源麻栎种子在安徽省滁州市红琊山林场进行苗期试验,结果表明:不同种源麻栎苗高、根长、地径、高径比、生物量、热值和能量均存在极显著差异.麻栎苗高和地径生长均表现"S"型曲线,7-9月为生长速生期;麻栎不同器官热值大小排序为叶＞茎＞根,生物量为根＞茎＞叶,能量为茎＞根＞叶.主成分分析表明:种源的差异主要是由各器官生物量决定.初步选出安徽太湖、安徽太平、浙江开化、江苏句容、浙江建德、浙江龙泉和贵州榕汀种源为优良种源.     

干旱胁迫下不同品种杨树矿质离子含量变化

【目的】了解杨树在干旱胁迫下矿质离子分布及其动态变化。【方法】以吴屯杨、新疆杨和荷兰杨为实验材料,在中度和重度干旱条件下测定了根、茎、叶和质外体的K^+、Ca^2+、Na^+和Mg^2+等4种离子含量的变化。【结果】干旱胁迫使K^+、Ca^2+和Na^+离子含量上升,Mg^2+含量下降,其中K^+和Ca^2+含量自胁迫开始明显升高,Na^+含量则在中度胁迫之后明显增加。离子在各器官分布情况为:K^+主要分布于杨树的叶片,Ca^2+、Na^+和Mg^2+主要分布于杨树根部,且离子分布存在品种间差异,荷兰杨和新疆杨中K^+分布为:叶>根>茎,而吴屯杨体内K^+分布则为:叶>茎>根;3种杨树中Ca^2+分布均为:根>叶>茎;吴屯杨和荷兰杨中Na^+分布为:根>茎>叶,新疆杨则为:根>叶>茎;在Mg^2+的分布上吴屯杨和新疆杨较为类似即:根>叶>茎,而荷兰杨为叶>根>茎。【结论】干旱胁迫下杨树首选吸收的离子是K^+和Ca^2+,K^+主要分布在杨树的叶片中,其次是根部,Ca^2+主要分布在杨树的根部。重度干旱胁迫下,杨树开始吸收Na^+,储存在杨树的根部。不同品种杨树之间离子的分布和吸收都存在品种差异。质外体作为离子的运输通道,在各干旱条件下运输4种矿质离子至杨树的其他部位,Mg^2+存在滞留在质外体中的情况。本研究可为植物在干旱胁迫下矿质离子吸收和分布的研究提供理论依据。     

国槐苯丙氨酸解氨酶基因的克隆、反义表达载体构建及遗传转化

根据其它植物PAL基因的保守区域,设计一对兼并引物,采用RT-PCR方法从国槐中克隆了一个长866 bp的PAL基因片段,命名为SjPAL.序列分析发现SjPAL多肽与其它植物的PAL氨基酸序列高度同源(87%以上),且包含与水稻和拟南芥的PAL类似的活性位点.系统进化树分析表明SjPAL与豆科植物的PAL亲缘关系较近.RT-PCR结果显示,SjPAL在根和茎的表达量约为叶中的3倍.利用反义RNA技术将SjPAL基因克隆至植物表达载体pBI121,构建了SjPAL反义RNA植物表达载体pBI121-PAL,通过根癌农杆菌EHA105将其导入拟南芥基因组,对获得的抗性植株进行PCR鉴定、Northern杂交分析、PAL活性分析以及总多酚含量和类黄酮含量分析.结果表明,该反义RNA已整合到拟南芥基因组中,转基因拟南芥的PAL基因表达量、单位材料PAL活性、总多酚含量和类黄酮含量均显著低于野生型对照.本研究为下一步利用该基因反义表达载体转化国槐,通过调节酚类物质含量提高其在再生体系中的生根能力提供了试验依据.     

栓皮栎不同种源苗期变异与初步选择

收集了栓皮栎分布区内25个种源种子,在肥西县花岗镇蔡冲村进行播种育苗试验,对其苗期生长性状、生物量进行测定分析。结果表明,栓皮栎苗高、地径生长均表现"S"形曲线,7—9月中旬为速生期;不同种源栓皮栎除根长存在显著差异外,苗高、地径、高径比、生物量均存在极显著差异;苗高与地径、茎、叶、总生物量呈极显著正相关,地径与根、茎、叶、总生物量也呈极显著正相关,根与茎、叶、总生物量同样呈极显著正相关。主成分分析表明,种源间的差异主要是由生物量和地径决定的。初步筛选出云南勐海、安徽东至、河南信阳、重庆酉阳、浙江杭州、安徽金寨2号、安徽绩溪7个优良种源。     

粗壮女贞的生物量研究

通过对粗壮女贞个体植株根、茎、叶生物量的测定，掌握了一年生粗壮女贞的实生苗和扦插苗的根、茎、叶的生物量。对8年生的实生苗造林植株也进行了生物量的测定。     

基质湿度对黄芪幼苗防御应答及根际微生物的影响

通过考察基质湿度对黄芪幼苗防御应答及根际微生物的影响,了解土壤水分在黄芪药材品质形成中的可能作用。采用渗灌控水方式控制盆栽黄芪基质水分,分光光度法测定黄芪幼苗根、茎、叶绿叶挥发物(green leaf volatiles,GLVs)合成途径关键酶——脂肪氧合酶(lipoxygenase,LOX)和苯丙烷类类物质合成关键酶——苯丙氨酸解氨酶(phenylalanin ammonia-lyase,PAL)活性和总黄酮含量,梯度稀释法测定根际细菌和真菌数量,SPSS软件进行数据分析。结果表明,高水分含量(81.6%)导致黄芪幼苗根际微生物数量显著下降,叶PAL和根LOX活性显著升高,但根中的总黄酮含量明显低于低湿度组的。相比较而言,低湿度组黄芪根际真菌和细菌数量无明显变化,且叶LOX活性较高。基质水分含量是影响黄芪黄酮合成与积累的重要因素,高基质湿度不利于黄芪黄酮类物质的合成与积累且很可能与根中高LOX活性有关,低基质湿度下较为稳定的根际微生物群落很可能是黄芪幼苗中黄酮类物质的合成与积累的有益因素。     

种间竞争对甘草柠条生物量积累和分配的影响

研究不同种植密度和不同混栽比例条件下甘草和柠条的生物量积累、分配模式及种间竞争动态.结果表明:混栽后甘草和柠条播种苗的平均单株生物量较纯栽都有所降低,柠条受种间影响的程度较甘草大.混栽甘草的根部和单株生物量较纯栽分别减少了18.12%和14.52%,地下部分受到的影响较地上部分大;混栽柠条的根部和单株生物量较纯栽分别减少了36.51%和44.74%,地上部分受到的影响较地下部分大.甘草根、茎、叶和单株生物量混栽与纯栽之间的差异都不显著;柠条根、茎、叶和单株生物量混栽与纯栽之间的差异达到显著和极显著水平.总的来说,混栽条件下甘草和柠条的相对总生物量(RYT)随着生长时间延长和密度的增大呈减小趋势.低密度混栽时,甘草和柠条表现出一定的互惠关系;高密度混栽时,二者共用资源受限,表现出相互拮抗的关系,且随着生长时间延长而加强.混栽比例不同,甘草和柠条的种间竞争率(CR)存在一定的差异,在柠条占有较大比例的处理(甘草20%;柠条80%)中,甘草的竞争力较小;在甘草占有较大比例(甘草80%;柠条20%)和两者比例相等的处理(甘草50%;柠条50%)中,甘草的竞争力均大于柠条.苗期甘草在混栽群体中具有较强的竞争优势.     

A new polysaccharide from leaf of Ginkgo biloba L

A water-soluble polysaccharide, GPB, was obtained from leaf of Ginkgo biloba L by hot water extraction followed by precipitation with ethanol and fractionation with gel chromatography. The results of HPLC with TSK-GEL column and gel filtration chromatography with Sepharose CL-6B analysis indicated GPB was uniform in polarity and its molecular weight (MW) was about 10 kDa. The structure of GPB was analysed using chemical methods, IR spectroscopy, and NMR spectroscopy. GPB has a high branched structure with polygalactose as core part of backbone. The repeating unit of polygalactose consists of 1,6-linked Galactose (Gal) and 1,3,6-linked Gal.     

Purification, characterization and evaluation of insecticidal activity of trypsin inhibitor from Albizia lebbeck seeds

A Bowman-Birk inhibitor with activity against gut proteases of Helicoverpa armigera was extracted in 0.1 M sodium phosphate buffer from defatted seed flour of Albizia lebbeck. It was purified to 29.62 folds with 51.43% recovery using ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-100 column and ion exchange chromatography on DEAE-Sephadex A50. The purified protein had a molecular weight of 12,303 daltons as determined by SDS-PAGE. It was found to be heat stable up to 60°C and had two pH optima of 7.5 and 9.0. The inhibitor exhibited non-competitive pattern of inhibition with a low Ki value of 0.2 μM. The inhibitor was found to be susceptible to varying concentrations of reducing agents like DTT and 2-mercaptoethanol, thereby indicating the role of disulphide bridges in maintaining its three dimensional structure and stability. The purified inhibitor caused mortality and suppressed larval growth of Pieris brassicae larvae. It was also found to be effective against gut trypsin extracted from Spodoptera littoralis. The sequence of the genes encoding for such inhibitors can be determined and the genes expressing protease inhibitors can be used in vegetable crops to confer resistance against insect pests and other plant pathogens.     

Anti-angiogenic effect of soybean kunitz trypsin inhibitor on human umbilical vein endothelial cells

Soybean kunitz trypsin inhibitor (STI) was purified from aqueous extract of defatted soybean meal by affinity and ion exchange chromatography. In this study the effect of purified STI on cell migration and tubulogenesis in microcarrier-based fibrin gel was assayed. Purified STI had strong inhibitory effect on human umbilical vein endothelial cells migration and tubulogenesis in fibrin matrix, without toxic effects in the studied doses.     

美国白蛾核型多角体病毒多角体蛋白的SDS－PAGE分析

美国白蛾Hyphantria cunea(Drury)1979年传人我国辽宁丹东[1]后,迅速扩散蔓延成灾.现多数分布在天津市、河北、辽宁、山东、陕西等省.在我国的寄主植物多达49科108属175种[2],给林业生产造成重大损失.1984、1996年两次列入全国森林植物检疫对象名单.     

Purification of a lectin-like antifungal protein from the medicinal herb, Withania somnifera

A 30 KDa monomeric acidic lectin-like protein was purified from the leaves of an important medicinal herb, Withania somnifera (L.) Dunal (Solanaceae), by a series of gel filtration and affinity chromatography methods. The inhibitory concentration of the protein ranged from 7 microg to 11 microg against major phytopathogens under in vitro conditions. The peptide sequence showed similarity to concanavalin A like lectin from Canavalia ensiformis and caused distinct cell wall adhesion of the protein treated hyphae under SEM. Further, the antifungal activity of the protein was compared with standard lectins like concanavalin A, phytohemagglutinin and wheat germ agglutinin.     

美国红枫变色期苯丙氨酸解氨酶与查儿酮异构酶变化研究

以美国红枫‘秋天火焰’（Acer×freemanif‘Autumn Blaze’）和‘白兰地’（Acer rubrum‘Brandywine’）为试材,研究美国红枫变色过程中,叶片中花青苷含量及其合成相关酶苯丙氨酸解氨酶（PAL）和查儿酮异构酶（CHI））的活性变化。结果表明：两红枫品种叶片中花青苷含量随天数的增加均为单峰曲线,分别在第20d和25d出现峰值;PAL酶活性与花青苷含量成二次曲线关系,CHI酶活性与花青苷含量呈极显著的线性关系;PAI、CHI是秋天火焰花青苷合成的关键酶,CHI是白兰地花青苷合成的关键酶。     

Lectin from the trunk of Sophora japonica

Summary Lectin was purified from the bark of Sophora japonica trunk by a simple method, affinity chromatography on acid-treated agarose; the yield was about 27% of the total sap proteins. Its molecular weight was 135,000±5,000 shown by using gel filtration, similar to that of the seed lectin of this species. When analyzed by using polyacrylamide gel electrophoresis (PAGE) under acidic and basic conditions, the lectin showed multiple bands. These patterns were different from those obtained with the seed lectin of the same tree. The trunk lectin had a broader specificity for the blood types than the seed lectin. These observations demonstrate that the trunk and the seed lectins from the same tree are different molecular species.Authors are grateful to D. Med. Sci. Kazuhiko Ito and M. D. Hisahiro Yoshida, University Hospital of Kyoto Univ., for kindly providing us with human erythrocytes several times     

Influence of water table decline on growth allocation and endogenous gibberellins in black cottonwood

Cottonwoods occur in riparian areas where water table depth generally varies with the elevation of the adjacent river. Plant adaptation to the riparian zone requires the coordination of root elongation to maintain contact with the water table during the summer decline. We investigated the effects of rate of water decline on growth allocation and concentrations of endogenous gibberellins (GAs) in black cottonwood (Populus trichocarpa Torr. & A. Gray ex Hook.) saplings. Rhizopods were used to achieve water decline rates of 0, 2 and 4 cm day(-1). Root elongation approximately doubled in response to the 2 cm day(-1) treatment, whereas leaf area was reduced. A water decline rate of 4 cm day(-1) led to water stress, as evidenced by reduced growth, increased leaf diffusive resistance, decreased water potential, and leaf senescence and abscission. Endogenous GAs were extracted, purified and analyzed by gas chromatography-selected ion monitoring with internal [(2)H(2)]GA standards. Across the sampled plant organs, GAs were generally highest in shoot tips and sequentially lower in basal stems, root tips, leaves and upper roots; GAs were thus abundant in rapidly growing tissues. Of the GAs measured, GA(1) tended to predominate, followed sequentially by GA(3), GA(8), GA(19), GA(20), GA(29) and GA(4). There was little relationship between GA concentration and growth allocation across the water table decline treatments, although GA(8) was consistently reduced in plants experiencing water table decline. Because GA(8) is the final gibberellin in the metabolic sequence, it might be useful for assessing historic patterns of GAs and growth rate. This study demonstrated changes in growth allocation in response to water table decline, but provided little evidence that endogenous GAs play a primary role in the regulation of root elongation in response to water table decline.     

NADPH-dependent ferrireductase produced by white-rot fungusPhanerochaete sordida YK-624

An intracellular, soluble ferrireductase thought to be involved in the reduction of manganese dioxide by white-rot fungusPhanerochaete sordida YK-624 was purified for the first time. Two isoenzymes, NAD(P)H-dependent and NADPH-dependent, respectively, were detected by hydrophobic chromatography. The NADPH-dependent ferrireductase was purified to homogeneity by ammonium sulfate fractionation, hydrophobic interaction, gel permeation, and anion-exchange chromatography. The purified protein, which is monomeric, has a molecular mass of 35 kDa (determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and pl 5.1 (determined by isoelectric focusing). The purified protein did not use cellobiose as an electron donor. The purified protein reduced Fe(III)-nitrilotriacetate complex, Mn(III)-malonate complex, methoxy-p-benzoquinone, and cytochrome c; veratraldehyde, 2-hydroxy-1,4-naphthoquinone, phenazine methosulfate, and plumbagin could not be reduced. Particularly, the protein showed the highest reducing rate for Fe(III)-organic acid complexes, such as Fe(III)-nitrilotriacetate, among these electron acceptors.