DNA Methylation Differences in Soybean Hybrids and Their Parental Lines

Abstract

To understand the methylation level and genetic delivery from parental line to their hybrid in soybean (Glycine max (L.) Merr.), four groups of parental lines and their hybrids were analyzed using methylation sensitive amplification polymorphism (MSAP). Comparisons of the different methylation distributions revealed. (1) The methylation level of the whole hybrid was lower than that of the corresponding parent lines, and the internal cytosine-methylation pattern was dominant. (2) In this study, comparing the total methylation levels in hybrids and the midparent values we assume that the larger differences in DNA methylation between parental lines lead to stronger heterosis. (3) Four demethylated and one hyper-methylated fragments were sequenced and located in the reference genome by blast analysis. These methylation changes could cause expression levels changes of a protein kinase, zinc finger protein and a mitochondrial transcript, which would affect a variety of metabolic pathways in soybean, providing an explanation for the observed heterosis.