In the present study, bisulfite sequencing(BS-seq) was performed to detect alterations in DNA methylation of acid invertase gene promoters in Cu-tolerant(MP) and nontolerant populations(NMP) of metallophyte Elsholtzia haichowensis under Cu treatment. We found that the vacuolar invertase gene(v INV) promoter of E. haichowensis was generally methylated in the CG site,whereas the cell wall invertase gene(cw INV) promoter displayed hypomethylation at the CG site. Methylation changes at a special CHG site of the...