The Effects Of Two Stress Treatments On Arabidopsis DNA Methylation

This paper uses model plant Arabidopsis thaliana as material,analyzing its methylation variations after cryopreservation treetment and heavy metals cadmium stress seprately.It was used methylation-sensitive amplified polymorphism(MSAP)technique to analyze the genomic DNA methylation.The main findings are as follows:1.The sample survival rates after cryopreservation influnced by the level of seeds germination,if the former is not complete,it had the low survival rate of seedlings after cryopreservation;and contrarily a higher survival rate.We can say that the survival rate of Seedlings after cryopreservation is higher than cryopreservation of seeds.Two days after the first cryopreservation,the control seedlings grew well and the two treatment groups very slow grew very slow;The difference gradually reduced at latter and it had grew basically the same.The second cryopreservation of two samples did not find differences in growth,both were growing well.2.The genome DNA of treatments and controls were analyzed by amplified fragment lenth polymorphism(AFLP)technique.The DNA were digested by EcoRâ… and Mseâ… ,and 594 bands were scored using 8 pairs of primers combination.No variation of bands was found during the five samples,which suggested that no nucleotide sequence of the seedlings had altered during cryopreservation.3.Methylation-sensitive amplification polymorphism(MSAP)was used to analyze the DNA methylation status of the treetments and controls.In all the 477 bands,100 bands were found changerable in the samples,and there were 24 bands could maintain the same between two descendants after the first cryopreservation.Amplification strips of all samples with a maximum of bands patternâ… ;â…¡bands pattern followed;â…¢bands pattern at least.4.The CdCl₂ treetment concentrations were 0.5,1.0,1.5,2.0,2.5,5.0,7.5,10.0,12.5,15.0,20.0,25.0 mg/L seperately.When CdCl₂ concentrations were 0.5～1.5 mg/L it promoted seed germination, but.When CdCl₂ concentration above 1.5 mg/L it was inhibited seed germination.The general trend was the higher the concentration of CdCl₂,the lower the germination rate.It had the lowest germination rate when the cadmium concentration was 25.0 mg /L,was 89.5%.Using MSAP analyzed the DNA methylation,It was showed that with the increasing of CdCl₂ poisoning effect increasing,the DNA methylation bands for the increase and decrease are both increased.