highly significantP < 0.001
Notably, the proportion of DMA in total rice arsenic concentrations exhibited a highly significant positive correlation with the core methylator-to-demethylator ratio ( r = 0.76, P < 0.001), which was much stronger than the correlation observed with the ratio of arsM to mcrA genes measured via qPCR ( r = 0.13, P = 0.053) ( SI Appendix , Fig.