Effect of different light quality on DNA methylation variation for brown cotton (<i>Gossypium hirstum</i>)

Abstract

DNA methylation plays an important role in regulating gene expression during plant development. We studied the effects of different light quality on DNA methylation patterns of brown cotton (Gossypium hirstum) by using the methylation sensitive amplified polymorphism (MSAP). We selected 66 pairs of MSAP selective amplification primers to assess the status of cytosine methylation, with diverse patterns and percentages of DNA methylation under different light quality. When the brown cotton was treated with blue, white + ultraviolet-B, red, white and yellow lights, respectively, frequency of total and full methylation were 24.15/13.64, 25.68/15.23, 27.09/16.35, 19.29/7.58 and 21.92/11.08%, respectively. In addition, 4 monomorphic fragments and 1 polymorphic fragment that appeared in the electrophoretogram were sequenced and analyzed. The sequences alignment revealed that both coding and non-coding regions could be methylated or demethylated by differing light quality, suggesting an epigenetic response of plants to light.

Key words: DNA methylation, methylation sensitive amplified polymorphism (MSAP), light response, light quality, cotton.