应用FTIR分析过量表达HPS/PHI转基因与野生型天竺葵叶片在甲醛胁迫下的生理特性差异

摘要

6-磷酸已酮糖合成酶(HPS)和6-磷酸果糖异构酶(PHI)是细菌同化甲醛的关键酶.13 C-NMR分析结果说明在天竺葵叶绿体中过量表达HPS/PHI融合蛋白可把RuMP途径整合成卡尔文循环的一个支路,在转基因天竺葵叶绿体中创造一个甲醛光合同化途径.运用FTIR技术分析过量表达HPS/PHI转基因与野生型天竺葵在甲醛胁迫下体内各物质含量的变化规律及光谱表征,考察FTIR能否成为一种鉴定有甲醛光合同化途径的转基因植物与野生型植物表型差异的新方法.分别用4 mmol- L-1甲醛处理野生型和转基因植物0,1,2,3,4d,通过对两种植物经甲醛处理不同时间后各光谱特征的比较分析发现,用4 mmol·L-1甲醛处理4d后转基因植物中的碳水化合物、蛋白质、脂肪族化合物等的含量明显高于野生型植物.这可能是由于安装HPS/PHI甲醛光合同化途径后使转基因植物同化代谢甲醛的能力更强,能将更多的甲醛固定为6-磷酸果糖,然后进入各种同化途径用于合成细胞内的各种组份所致,说明FTIR可作为一种鉴定有甲醛光合同化途径的转基因天竺葵与野生型天竺葵表型差异的新方法.%In the present study, FTIR was used to analyze changes in chemical component contents and spectra characters of 3-hexulose-6-phosphate synthase/6-phosphate-3-hexuloisomerase (HPS/PHI) over-expressing transgenic and wild-type (WT) geraniums under formaldehyde (HCHO) stress to examine if FTIR could be a new method for identification of phenotypic differences between the transgenic plants with a photosynthetic HCHOassimilation pathway and the WT plants. The WT and transgenic geranium plants were treated with 4 mmol·L-1 HCHO for 0, 1, 2, 3 and 4 days, respectively. The comparison of FTIR spectral characteristics at different time points between the transgenic and WT plants indicated that the contents of carbohydrate, proteins and aliphatic compounds were significantly higher than those in the WT plants after 4 days of HCHO-treatment. This may be due to installation of the photosynthetic HCHO-assimilation pathway in the transgenic geranium, which enhanced its a-bility to metabolize and assimilate HCHO, thus allowed more HCHO to be fixed to 6-phosphate fructose, and then entered assimilation pathways for synthesis of a variety of intracellular components. The results suggest that FTIR can be a new method to identify the phenotypic differences between transgenic plants with a photosynthetic HCHO-assimilation pathway and WT plants.