滤纸对青蒿丛生芽诱导及遗传转化的影响

研究了滤纸对青蒿丛生芽诱导及遗传转化的影响.结果表明,培养基上加铺一层滤纸能够明显促进青蒿丛生芽的诱导,丛生芽诱导率可达到97%.在高效丛生芽诱导体系的基础上,探讨了滤纸在根癌农杆菌介导的青蒿遗传转化中的应用.优化后的青蒿转化体系,抗性丛生芽诱导率可达到59.7%,其中,12.5%的抗性丛生芽能发育成抗性生根植株,生根植株PCR检测均为阳性.在部分PCR检测阳性植株中检测到了GUS的稳定表达.该优化的转化体系对青蒿素生物合成分子调控的研究具有重要意义.图5表1参26     

GUS基因在诸葛菜子叶原生质体中的瞬间表达

本文以诸葛菜无菌苗子叶组织为材料，采用原生质体培养获得成功，建立了原生质体培养高频再生体系，植板率３％，植株再生频率１００％。在此基础上，本文首次研究了ＰＥＧ介导转化诸葛菜原生质体的影响因素，系统地试验了ＰＥＧ法转化子叶原生质体的过程，发现：最适质粒量为２５－３０μｇ；ＰＥＧ终浓度为１５％，ｐＨ８．０；另外，表达效率还与质粒的大小有关，较小的质粒具有相对较高的转化效率；而ＣＴ－ＤＮＡ以及热击处理未     

Adsorption and degradation of sulfosulfuron in soils

Adsorption of sulfosulfuron was studied in two soils (topsoil from Alfisol and Inceptisol). The adsorption of sulfosulfuron was greater in topsoil collected from Alfisol than in Inceptisol. The soil sorption coefficient K and the soil organic carbon sorption coefficient K _oc are the basic parameters used for describing the environmental fate of the herbicides. In topsoil the calculated K values from Alfisol was 4.43 and in topsoil from Inceptisol was 2.00. K _c values were 6.06 in topsoil from Alfisol and 3.33 in topsoil from Inceptisol. The K _oc values were 886.36 in topsoil from Alfisol and 770.26 in topsoil from Inceptisol. Field experimental plots with no previous history of sulfosulfuron were selected and studied the degradation of sulfosulfuron in the topsoil collected from Alfisol and Inceptisol. The half-life of sulfosulfuron in topsoil from Alfisol: T ₁− 3.97 days and T ₂− 4.54 days; topsoil from Inceptisol: T ₁ − 4.68 days and T ₂ − 5.52 days. The degradation of sulfosulfuron followed first-order kinetics. The persistence of sulfosulfuron was found relatively longer in the Inceptisol than in Alfisol. The combination of degradation data (t _1/2 – soil) and organic carbon based sorption (K _oc) data of herbicides have been used to assess the pesticide environmental impact in soils through Gustafson Ubiquity Score (GUS). The GUS values were found to be 0.69 in topsoil from Alfisol and 0.83 in Inceptisol.     

Use of different organic wastes in reducing the potential leaching of propanil,isoxaben, cadusafos and pencycuron through the soil

In this study, we examined the effect of four different organic wastes (OW)—composted sheep manure (CSM), spent coffee grounds (SCG), composted pine bark (CPB) and coir (CR)—on the potential groundwater pollution of propanil and isoxaben (herbicides), cadusafos (insecticide) and pencycuron (fungicide) under laboratory conditions. For this purpose, leaching studies were conducted using disturbed soil columns filled with a clay loam soil (Hipercalcic calcisol). The addition of organic matter (OM) drastically reduced the movement of the studied pesticides. The results obtained point to the interest in the use of agro-industrial and composted OW in reducing the groundwater pollution by pesticide drainage.     

Leaching potential of some phenylureas and their main metabolites through laboratory studies

BACKGROUND, AIMS AND SCOPE: Laboratory studies were conducted with the aim of defining the leaching potential of some phenylureas and their metabolites. A first study was performed for calculating their leaching index (as GUS) on the base of intrinsic properties: persistence (as DT50) and mobility (as Koc) in soil. Another study consisted of aged column leaching experiments whose meaning was to semi-quantify the occurrence of the tested compounds in the leachates, so simulating in field conditions. METHODS: The tested compounds were: diuron, linuron and monolinuron (parents); 3,4-dichloroaniline (DCA), 4-chloroaniline (CLA), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU), 1-(3,4-dichlorophenyl)urea (DCPU), 1-(4-chlorophenyl)urea (CPU) and monuron, this latter considered both as a metabolite and parent compound. The Koc values of the examined substances were determined by the HPLC screening methods, according to the OECD TG 121. DT50 determinations and aged column leaching experiments were carried out according to SETAC procedures. RESULTS AND DISCUSSION: The examined compounds showed a rather wide range of persistence in soil, with DT50 values less than 2 days for DCA and CLA, close to 8 days for DCPU and CPU and from 16 (diuron) up to 24.8 (DCPMU) days for the others. Their mobility was generally high, based on their Koc values, which ranged from 33 (CPU) to 406 (linuron). The GUS indices indicated that monuron has a clear potential to contaminate groundwater (> 2.8); DCPMU, monolinuron, CPU and diuron are intermediate contaminants (1.8-2.8). Linuron, DCPU, CLA and DCA exhibited a non-leaching behaviour (< 1.8). The aged leaching column experiments showed that parents were found in the leachates at very high percentages respect to the doses applied. The metabolites reached much less percentages, the highest values were observed for monuron from diuron (5.7), CPU (7.2) and DCPMU (8.2%). CONCLUSION: Diuron, Monuron, CPU and DCPMU on the basis of their intrinsic properties, formation from their parents and occurrence in leachates from aged column leaching studies, seem to possess the characteristics of groundwater contaminants. The methodological approach of this study is relatively easy and rapid, hence it can represent a tool for a first screening of compounds such as pesticide metabolites (generally available only in small quantities and for which a field study is not conceivable) or other compounds for which not adequate environmental data are available.     

等鞭金藻的电转化体系

以等鞭金藻(Isochrysis sp.CCMM5001)为材料,探索了影响其电转化的主要因素,建立了等鞭金藻电转化体系。结果表明,真空抽滤法收集藻体获得的细胞存活率明显高于离心收集法;藻体收集的最适缓冲液为1.0 mmol/L HEPES(pH7.5)(含0.5 mol/L蔗糖);相同电场强度下,对数早期的藻细胞存活率最高,早、中、晚期的半致死电场强度分别为0.82～1.63 kV/cm、0.79～1.34 kV/cm、0.54～1.18 kV/cm;最佳脉冲时间为5 ms;冰浴时间为10 min。通过电击转化法向球等鞭金藻中导入质粒pCAMBIA2301,并对转基因球等鞭金藻进行GUS组织化学染色和GUS荧光定量分析,检测pCaMV 35S启动下的GUS报告基因的表达。得到转基因球等鞭金藻的GUS活性为0.52 nmolMU/(min.mg)。通过PCR方法检测固体平板上的单藻落,结果显示转化藻株能够检测到nptII基因。本研究建立了等鞭金藻的电转化体系,为外源基因的导入及其功能的研究奠定了基础。     

Exotic gene expression in transgenic plants as a tool for monitoring environmental pollution

Environmental monitoring can benefit from the application of molecular and biochemical techniques as biomarkers. In principle, molecular biomarkers may have some advantage over more classical, organismal level markers because of their sensitivity, efficiency and reproducibility. Nevertheless, some disadvantages such as the cost, resource requirements and lack of specificity have limited their widespread use. Molecular genetics and recombinant DNA technologies, however, allow to improve simplicity and cost, together with reliability, efficiency and sensitivity, of molecular biomarkers. The stress inducible promoter of the barley gene Hvhspl7, which is induced by a number of environmental stress (including some heavy metals), has been fused to the reporter gene GUS in a plasmid. This plasmid was used for stable transformation of tobacco. Some of the transgenic plants obtained after selection showed enhanced GUS expression after exposure to some heavy metals. Maintenance of the plants for three generations, and the analysis of the response to treatments, suggest that these transgenic plants may be utilised as an affordable biomarker for monitoring heavy metal pollution.