DNA甲基化與植物基因之表現息息相關，因為那些經常不表現的基因有著高度的甲 基化情形的發生。DNA甲基化與基因表現之調控機制，可能直接與轉錄因子與DNA的鍵結與否 有關，或間接與染色質的結構發生關連。DNA去甲基化與基因表現的證據顯示基因表現與甲 基化的關係。一個可能的機制為DNA鍵結蛋白能否與DNA鍵結由DNA是否甲基化所調控而與基 因是是否表現有關。再者，植物賀爾蒙扮演訊息傳導而改變染色質構形而影響DNA鍵結蛋白 與DNA的交感作用，可能提供一個研究的方向。本文之目的即在於探討DNA甲基化與植物基因 表現的各種可能機制及其影響。
Methylation of deoxycytosine residues in plant nuclear genes at CpG dinucleotides is assumed to supress transcriptional activity. DNA methylation appears to be associated with gene inactivation. The cues for this may lie in the prevention of the binding or passage of transcription complexes or alteration of the conformation of chromatin, thus rendering the genes unable to be transcribed. The evidence of inactivation of gene activity by DNA methylation and the reactivation of gene expression by demethylation have shown us the involvement of methylation in gene regulation. A possible mechanism, through inhibition of DNA-protein interaction and chromatin conformation, has prompted us to realize that phytohormones (auxin, ABA) may mediate the gene regulation of plant development that can be used to explain the intrinsic trans-acting mechanism of DNA methylation occurring in plant systems associated with the chromatin structure and conformation, indication of the involvement of pyhtohormones in the regulation of DNA methylation pattern and gene expression may give us some clues to follow in further research. This paper discusses the relationship between DNA methylation and gene expression in the plant genome.
