Pb uptake, accumulation, subcellular distribution in a Pb-accumulating ecotype of Sedum alfredii (Hance)

Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes of Sedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations supplied as Pb(NO3)2. Lead concentrations in leaves and stems of the accumulating ecotype were 4-9 times and 3-5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of the accumulating ecotype were 4-9 times and 8-11 times higher than those of the non-accumulating ecotype, respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots to shoots. The subcellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fraction in stems of the accumulating ecotype and the percentage increased to 80% both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb.     

Pb uptake,accumulation, subcellular distribution in a Pb-accumulating ecotype of<Emphasis Type="Italic">Sedum alfredii</Emphasis> (Hance)

Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes ofSedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations supplied as Pb(NO₃)₂. Lead concentrations in leaves and stems of the accumulating ecotype were 4–9 times and 3–5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of the accumulating ecotype were 4–9 times and 8–11 times higher than those of the non-accumulating ecotype, respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots to shoots. The subcellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fraction in stems of the accumulating ecotype and the percentage increased to 80% both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb. Project supported by a Key Project from the Educational Ministry of China (No:02180) and by the Outstanding Young Scientist Grant from the National Natural Science Foundation of China (No: 39925024).     

牛膝营养器官解剖结构与三萜皂苷积累的关系

采用组织化学定位、显微制片和定量分析方法,对牛膝(Achyranthes bidentata)营养器官解剖结构特点、三萜皂苷含量及三萜皂苷积累场所进行了研究。结果表明,牛膝的根和茎均属于异常结构,根中具有同心环状排列的三生维管束,三生维管束的轮数最多可达7~8环;茎中具有2个髓维管束;叶为异面叶,海绵组织中具有发达的通气组织。牛膝根、茎和叶中均积累三萜皂苷,含量依次为:叶>根>茎。根中以三生韧皮部为主要积累场所;叶内主要积累于栅栏组织细胞内。     

植物修复的应用:毛竹苗对铅的积累与耐性研究(英文)

目的:探索毛竹在修复铅污染土壤的植物修复潜力。创新点:使用了毛竹作为一种全新的植物修复材料进行研究。得到了毛竹幼苗在铅胁迫下的生长与生理反应情况,不同植物组织对铅的吸收与积累情况,铅胁迫下毛竹幼苗表层与细胞超微结构的特征。方法:根系形态分析(图3)、植物重金属含量分析(表1)、扫描电镜分析(图4)和透射电镜分析(图5)。结论:各组织部位铅浓度的值揭示了,毛竹是一个很好的固定铅污染土壤的植物材料;但是由于毛竹茎的高生物量,也可以作为铅污染土壤的植物修复材料。在0~200μmol/L铅处理下,毛竹的生物量与根系形态没有显著性差异,生长正常未出现中毒症状。通过扫描电镜观察铅胁迫导致叶片的气孔减少,根与茎内含物增多。通过透射电镜观察高浓度的铅胁迫导致部分细胞内部叶绿体变形、内质网消失、细胞核与核仁缩小和类囊体膜消失。尽管超微结构观察到细胞内部的损害,但是未出现视觉的毒性症状。毛竹铅的高耐性与茎的高生物量,提供了毛竹作为材料修复土壤重金属铅更大的可能性。     

Accumulation and ultrastructural distribution of copper in Elsholtzia splendens

Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At ＞250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast＞cell wall＞soluble fraction＞other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels＞250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels＞250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens.     

铅胁迫对凤眼莲氮代谢关键酶的影响

研究不同浓度Pb2＋胁迫凤眼莲0.25,6,20,60 d,其氮代谢关键酶活性的变化.结果表明：在凤眼莲根、叶中均有谷氨酰胺合成酶（GS）和谷氨酰胺α-酮戊二酸氨基转移酶（GOGAT）的分布,无论是否有Pb2＋胁迫,凤眼莲的根、叶的GS活性大于NADH-GOGAT活性,且GS活性和NADH-GOGAT活性均表现为叶大于根.0.1~2 mmol.L-1Pb2＋胁迫凤眼莲0.25,6,20,60 d,其根和叶的GS活性降低,但在胁迫60 d后随着凤眼莲新生组织的萌生,各处理浓度GS活性均出现不同程度的上升.凤眼莲叶片的GOGAT活性受Pb2＋的影响在其处理60 d后极为明显,极显著上升.     

离子注入对烟草苗期生长发育的影响

本文用不同剂量的氮离子注入Ｎｃ（８９）烟草种子，研究对苗期生长发育的影响。结果表明：离子注入不同剂量对烟草苗期生长有不同的作用。对叶片长、宽、茎高、整粗的增长及干物质的积累都有促进作用，与对照比较都达到显著水平，有些达到极显著水平，对烟苗出叶速率，根长，根幅、侧根数，多数处理有促进作用，其中表现较好的处理有Ｍ（１７）（１６０次），Ｍ５（４０次）．Ｍ９（８０次）。     

翻白草中鞣质的超声提取工艺研究

采用超声波提取方法,以提取物中总鞣质含量为评价指标,探讨翻白草中鞣质的最佳超声提取工艺．对影响鞣质提取效果的各个因素：提取剂种类及浓度、料液比、提取时间、提取次数、提取温度进行了优化选择．实验结果表明,最佳提取条件为50％乙醇、料液比为1：60、超声时间为4h,提取温度为50℃．对翻白草不同部位（根、茎和叶）鞣质含量的分别测定,发现根、茎的鞣质含量大于叶的鞣质含量．     

~(133)Cs胁迫对转IrrE油菜生理活性的影响

以转IrrE基因油菜为材料,以非转基因油菜为对照,砂培条件下研究了油菜对Cs的积累吸收情况和Cs胁迫对油菜SOD、POD酶活性、MDA含量及游离脯氨酸含量的影响.结果表明:随着处理浓度的增大,转基因油菜和非转基因油菜对Cs的吸收量都增大,二者根部的吸收量都大于其地上部分;转基因油菜根部的积累量大于非转基因油菜根部的量,而地上部分积累量小于非转基因油菜的含量;在不同Cs浓度的胁迫下,转基因和非转基因叶片的SOD和POD活性均呈现先升后降的趋势,4种Cs浓度处理下转基因油菜活性都高于非转基因油菜;转基因和非转基因油菜叶片的MDA含量均呈上升的趋势,但转基因油菜体内的MDA含量都低于非转基因油菜;4种处理下油菜叶片脯氨酸含量也表现出上升趋势,而转基因油菜产生的游离脯氨酸高于非转基因产生的.以上结果说明在油菜受到Cs胁迫时,转IrrE基因油菜比非转基因油菜更具有Cs胁迫耐受性.     

显齿蛇葡萄多糖的提取工艺及含量研究

采用热水浸提法提取显齿蛇葡萄多糖,用蒽酮-硫酸比色法测定糖含量,通过单因素试验研究提取温度、次数、时间及液料比对糖含量的影响,并采用L9（3^4）正交试验对提取工艺进行优化．以最佳工艺提取不同时期显齿蛇葡萄茎、叶的多糖并测定其含量．结果表明,对多糖含量的影响因素由大到小依次为提取温度、次数、时间和液料比．显齿蛇葡萄多糖...     

吲哚乙酸（IAA）对大蒜根生长发育的影响

以10^-4、10^-5、10^-6、10^-7、10^-8、10^-9、10^-10、10^-11、10^-12和0mol/L的IAA对大蒜进行生根处理7天后,观察根尖细胞有丝分裂指数、生根数量及根质量的变化。在一定浓度范围内,大蒜根生长发育与IAA浓度呈正相关,10^-9mol/LIAA最利于大蒜根生长发育,随IAA浓度进一步升高,反而抑制根的生长发育。吲哚乙酸对大蒜根的生长调控具有两重性,较低浓度促进生长,较高浓度抑制生长。     

云南鸡屎藤根、茎、叶水提取物的体外抗菌研究

目的：研究云南鸡屎藤根、茎、叶水提取物的体外抑菌、杀菌作用。方法：采用常量稀释法测定云南鸡屎藤根、茎、叶水提取物分别对金黄色葡萄球菌、痢疾杆菌、大肠杆菌、绿脓杆菌的体外抑菌、杀菌作用。结果：云南鸡屎藤根、茎、叶对4种供试菌均有抑菌、杀菌作用,其中根对绿脓杆菌的抑菌、杀菌作用最强,对4种供试菌的抑菌、杀菌作用在3个实验药中均最优。叶对痢疾杆菌的抑菌作用最强,对金黄色葡萄球菌的杀菌作用最强。结论：云南鸡屎藤根、茎、叶水提取物对4种供试菌都有抑菌、杀菌作用,但存在明显差异,为下一步中药抗菌的标准化提供基础。     

浅谈余秋雨的散文特色

余秋雨散文的特色 ,即 :追寻文化是根 ,表达民族情感是茎 ,描述生活点滴是叶 ,这三者共同熔铸了茂盛而充满活力的秋雨散文之树。     

一株互花米草耐重金属内生菌的分离及其特性分析

利用微生物分离培养方法从互花米草根部和叶片获得内生细菌,经重金属筛选,分离到一种耐受重金属Cu2＋、Pb2＋和Cr6＋的细菌．为了进一步鉴定分离菌株,利用 PCR 方法扩增其部分16S rDNA 序列,目标DNA条带约1500 bp,测序和在线分析结果后显示,所测序列均与基因库中已上传的 Lysinibacillus sphaericus菌株16S rDNA 序列（KJ878614．1,JN613478．1）相似性均为100％．初步鉴定该菌为 Lysinibacillus属球形芽孢杆菌（Lysinibacillus sphaericus）,命名为Lysinibacillus sphaericus QZ1-1．对该菌株采用促生长特性分析结果显示,该菌株具有产生 IAA和 ACC的能力,同时该菌能在无氮培养基中生长,具备固氮功能,为日后重金属污染生物修复相关研究提供了良好的目标菌株．     

苦参不同器官中的生物碱含量分析

[目的]探讨苦参不同器官中的生物碱含量,为该资源植物的合理应用提供依据.[方法]用薄层色谱法(TLC)分析测定了辽宁产苦参不同器官中苦参碱及氧化苦参碱含量.[结果]各类器官,除叶片外,氧化苦参碱含量均显著超过苦参碱含量;苦参碱含量以种子中的为最高,占干重的0.065%,其次为茎(0.034%)、根(0.016%)、叶(0.013%);氧化苦参碱含量以根最高,占干重的3.847%,其次为种子(1.982%)、茎(0.140%),叶中未检测到;粗老根(直径大于1 cm)与细嫩根(直径在0.5~1.0 cm)中的两种生物碱含量差别不大.[结论]达到一定生长年限后,生物碱积累不再有明显增加而趋于饱和;大部分器官中,氧化苦参碱含量高于苦参碱含量;种子及茎更适合作为苦参碱的提取器官.     

番茄（Lycopersicum esculentum）几丁质酶基因LeCHI的克隆与序列分析

根据GenBank发布的几丁质酶基因序列设计PCR引物,从叶片cDNA中克隆到了番茄几丁质酶基因,并命名为LeCHI,基因在NCBI中的登陆号为FJ849060。测序结果表明,LeCHI编码区全长为762 bp,编码253个氨基酸。RT-PCR检测表明,LeCHI基因在根、茎、叶和花蕾中均有表达。序列比对结果表明,LeCHI编码的氨基酸序列与同科的马铃薯、辣椒有较高的同源性。     

乙醇和微波提取苦瓜叶中黄酮类物质的工艺研究

以苦瓜叶为原料,采用正交试验的方法对苦瓜叶中黄酮类物质用乙醇和微波法进行提取,试验结果表明,影响乙醇提取因素由强到弱顺序为:乙醇浓度>料液比>提取温度>提取时间,得到比较优势的组合为乙醇浓度为80%,料液比1:30,提取温度为70℃,提取时间4h.在微波法中影响苦瓜叶中总黄酮的提取效果各因素顺序为乙醇浓度>料液比>提取温度>提取时间,而得出比较优势组合为乙醇浓度为70%,液料比50:1,提取时间为3min,提取次数为3次.从时间及成本等方面考虑微波法值得推广采用.     

蝴蝶兰离体快繁新技术研究

采用正交设计的方法,研究6-苄基氨基腺嘌呤（6BA）浓度、萘乙酸（NAA）浓度、接种密度和蔗糖浓度4个因素对于蝴蝶兰繁殖系数的影响;采用无菌注射的方法,定期向培养基质泥炭藓中注射含NAA、6BA和蔗糖的MS液体培养基。结果表明,蝴蝶兰增殖系数可达到4.0以上,且试管苗健康茁壮,叶片油绿,气生根粗壮;移栽成活率可达到80%。     

土壤介质中镉污染对辣椒的影响

以盆栽辣椒为试验材料,用不同浓度的外源Cd处理土壤,观察记录辣椒的生长变化同时监测辣椒根、茎、叶、果实对Cd的累积吸收量;通过线性方程确定安全种植辣椒的Cd污染土壤的阈值.结果表明,随着土壤中添加的外源Cd量的增加,辣椒的长势明显变差,产量均小于对照,辣椒的根、叶、果实对Cd的吸收随着外源Cd量的增大而呈上升趋势,Cd在根内的积累大于在茎、叶、果实中的积累.当外源Cd质量浓度达到1.0 mg· kg^-1时,辣椒中的Cd含量可达到0.069 mg·kg^-1,超出GB2762-2005食品中污染物限量.该论文的工作为建立更加完善的绿色辣椒生产提供参考.     

南京市城郊零散菜地土壤及青菜中重金属含量特征

采集了南京市城郊零散菜地土壤和青菜配对样品各18个,用原子吸收光谱仪测定了其中铜、锌、铅、镉的含量,结果表明:南京市城郊菜地土壤中Cu、Zn、Pb、Cd全量高于农区菜地土壤,Cu、Zn达到显著差异,重金属含量在土样之间有较大的变异性,反映了人为活动已对南京城郊土壤重金属产生了明显影响。城郊土壤上种植的青菜其可食部分重金属含量高于农区,尤其是对人体健康影响较大的Pb、Cd含量与农区相比存在显著差异,大大超过国家食品卫生标准。