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.

Abbreviation

UV-B, Ultraviolet B; CPRF1, common plant regulatory factor 1;CPRF2, common plant regulatory factor 2; LAF1, long after far-red light 1; bHLH,basic helix-loop-helix protein; CTAB, cetyl trimethyl ammonium bromide; MIP, major intrinsic proteins; TIP, tonoplast intrinsic protein; PIF, proteolysis-inducing factor;phy, phytochrome; GBFs, G-box-binding transcription factors; MSAP, methylation-sensitive amplified polymorphism; PCR, polymerase chain reaction; EDTA,ethylenediaminetetraacetic acid; BLAST, Basic Local Alignment Search Tool;NCBI, National Center for Biotechnology Information; MIP, major intrinsic proteins;BAC, bacterial artificial chromosome; PEP, phosphoenolpyruvate.