The Cold Function Indentifiction And Mechanism Of PtrICEl

Plants always suffer the adversity stress like low temperature in natural environment, and the transcription factor called ICE1plays an important regulating effect in plant hardiness,but its mechanism of action research is still very clear. In this study, we have identified the cold resistance of transgenic tobacco,and analyzing the transgenic plants of cold hardiness and its possible mechanism. The main results are as follows:1.We found that the wild type plants were more serious withering than transgenic tobacco (OE22and C12) after0℃in the condition of dark treatment for24h. Relative conductivity showed that the transgenic plants were lower than WT; DAB and NBT staining results showed that the staining of the transgenic lines OE22and C12were weaker than WT,indicating that WT accumulated more H2O2and O2-.Enzyme assay results showed that POD、CAT and SOD enzyme activity in two transgenic lines were significantly higher than WT.2.The polyamine of transgenic and WT tobacco plants were detected by high performance liquid chromatography (HPLC) after subjected to cold stress for24h,the results which showed that the levels of put、spd and spm in transgenic plants were significantly higher than in the WT.RT-PCR showed that expression levels of ADC1and ADC2were higher than that in the WT after subjected to cold stress.The transgenic plants were sprayed ADC inhibitor in normal condition with the concentration of5mmol Per liter,and the phenotype identification result showed that the cold resistance of transgenic plants has reduced.At the same time,we preliminary found that there were interactions among PtADC and PtICE1genes by yeast two-hybrid technology.3.Two positive transgenic plants were identified by PCR in poncirus transformed with PtrICE1-RNAi.We choose the two transgenic system named S13and S17which were treated in the dark enviroment with-4℃for24h.The interference suffered greater damage than the WT.Relative conductivity was significantly higher than the WT.DAB and NBT staining results showed that the staining of the transgenic lines S13and S17were stronger than WT,indicating that the transgenic plants accumulated more H2O2and O2-.