Methylation of DNA in the chloroplasts and amyloplasts of the pea, Pisum sativum 

 -  Plant Science, 78(1), p.33-42, 1991 .
<br/><br/> Digestion with methyl-sensitive and methyl-insensitive isoschisomers of several restriction endonucleases showed that a small but significant amount of cytosine residues of the chloroplast DNA in the pea, Pisum sativum, was methylated. HPLC analysis of component nucleosides indicated that about 0.5 percent of cytosine residues in the chloroplast DNA was methylated at C-5. The methylationwas not related to aging of the plant. Cytosine residues of most of the CC(A/T)GG sites and some of the GATC sites in the chloroplast DNA were partially methylated in three genes examined, rbcL, atpB and psbDC. Most of the cytosine residues at the same sites in the amyloplast DNA were also methylated, while some of the sites were not methylated in the amyloplast DNA. Apparently, these methylation cannot be involved in the regulation of gene expression, and possible roles of the methylation of chloroplast DNA are discussed. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>5-METHYLCYTOSINE<br/>AMYLOPLAST DNA<br/>CHLOROPLAST DNA<br/>DNA METHYLATION<br/>PISUM SATIVUM