Carpel, a new Arabidopsis epi-mutant of the SUPERMAN gene: Phenotypic analysis and DNA methylation status

Abstract

The carpel (car) mutation affects the morphology of reproductive organs in Arabidopsis thaliana, car flowers have an increased number of carpels, on average 2.7±0.8 instead of two in the wild type. Through allelism test with fon1-3 and analysis of the methylation state of the SUPERMAN (SUP) gene in car mutants, we show that car is an epi-mutation of SUP. The methylation pattern of car is clearly distinct from that of fon1-3, another epi-mutation of the SUP gene. Methylation was found predominantly in Cp(A/T)p(A/G) triplets and in CpG pairs. We suggest that the extensive SUP methylation in car has arisen from an abundant methylation of a single CpG site that was already present in abscisic acid-insensitive (abi3-4) mutants, from which car was segregating.