CHROMOMETHYLTRANSFERASE3/KRYPTONITE maintains the <i>sulfurea</i> paramutation in <i>Solanum lycopersicum</i>.

Abstract

SignificanceParamutation involves the transfer of a repressive epigenetic mark between silent and active alleles. It is best known from exceptional non-Mendelian inheritance of conspicuous phenotypes in maize but also in other plants and animals. Recent genomic studies, however, indicate that paramutation may be less exceptional. It may be a consequence of wide-cross hybridization and may contribute to quantitative trait variation or unstable phenotypes in crops. Using the <i>sulfurea</i> (<i>sulf</i>) locus in tomato, we demonstrate that a self-reinforcing feedback loop involving DNA- and histone-methyl transferases CHROMOMETHYLTRANSFERASE3 (CMT3) and KRYPTONITE (KYP) is required for paramutation of <i>sulf</i> and that there is a change in chromatin organization. These findings advance the understanding of non-Mendelian inheritance in plants.