The epigenetic basis of complex traits in plants

In the March 7^th issue of Science Cortijo et al. are able to quantify the impact of heritable epigenetic variation on traits in the model plant Arabidopsis. They used inbred plant lines that share identical DNA, yet have differentially methylated regions (DMRs). They showed that DMRs can be stably inherited independently of DNA sequence changes and function as epigenetic quantitative trait loci (QTL). Several of the DMRs acting at epigenetic QTL accounted for 60-90% of heritability for two complex traits, flowering time and primary root length. The detected epigenetic QTL have all the necessary phenotypic properties to become targets of natural or artificial selection. The authors suggest their findings are a component of the so-called “missing heritability.”