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Analysis of two important air pollutants, fluoride and ozone, in plants
Ion Chromatography;Ion Selective Electrode;Fluoride;tea;GDCH;ozone;Bidens pilosa var. radiat;Arabidopsis thaliana
|Issue Date: ||2013-11-07 12:20:56 (UTC+8)|
|摘要: ||The purpose of this research is to develop methods to evaluate the effects of two important air pollutants, fluoride and ozone, on plants and report some evaluation results.|
Fluoride is one main air pollutants affecting the quality and yields of crops in Taiwan. Tea (Camellia sinensis) is a perennial plant capable of taking up fluoride from soil and accumulating it in leaves. The fluoride ion selective electrode was first used to analyze the fluoride contents in tea leaves and tea infusions prepared from different types of tea. The fluoride contents in tea leaves were determined to be 133-451 mg/kg dry weight. Those in 1% infusions of 89 leaf tea samples, 42 bagged tea samples and 78 ready-to-drink tea beverage samples ranged from 0.14-2.31 mg/L, 0.23-3.60 mg/L and 0.43-2.51 mg/L, respectively. The daily exposure of fluoride from tea drinks for a Taiwanese was assessed. Furthermore, in order to correctly determine the fluoride content in tea infusion by ionic chromatography, a pretreated method was developed to eliminate the interference present in tea infusions.
In addition to fluoride, the increasing of troposphere ozone is another important pollutant affecting the quality and yield reduction of crops in Taiwan. Through successive self-pollinations, two F2 offspring plants that showed difference in ozone tolerance were obtained from one Bidens pilosa var. radiat plant. Two-dimensional (2-D) gel electrophoresis analysis of the total proteins of the two offspring plants revealed a protein spot specific only to the one offspring sensitive to ozone, but not the other offspring tolerant to ozone. This specific protein spot was identified to be the H subunits of the glycine decarboxylase (GDCH) protein complex by LS-MS/MS. cDNAs of GDCH from the two offspring were PCR-cloned and sequenced. At least one cDNA was found specific for the sensitive offspring, but not for the tolerant offspring, with PI and molecular weight corresponding to the specific protein spot in the 2-D gel. The model plant Arabidopsis thaliana was used to further analyze the role of GDCH in ozone tolerance by knock-in transgenic technology and western analysis. The results showed reduction of ozone tolerance with the two transgenic plants with low and undetectable expression of the H protein, but no difference with the transgenic plants that showed high expression of the H protein, as compared to the wild-type plant or the control transgenic plant that did not carry the cDNA of GDCH in the genome. It is hypothesized that small amount of exogenous H protein would decrease the amount of the endogenous GDCH protein complex (negative dominance). But high amount of the exogenous H protein would result in formation of H protein oligomers, with would have no effect on the endogenous GDC complex. Ozone tolerance of plant was very likely affected by the amount of the GDC protein complex in plant.
|Appears in Collections:||[依資料類型分類] 碩博士論文|
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