SET domain-containing protein genes are involved in Arabidopsis thaliana embryogenesis

Abstract

Many genes are temporally and spatially regulated during embryogenesis in higher plants. Although many studies have examined transcriptional factors relating to gene regulation during embryogenesis, the molecular mechanisms relating to the initiation of embryogenesis are still unclear. In animals, it was reported that gene regulation by chromatin remodeling contributes to embryogenesis. In contrast, the relationship between chromatin remodeling and the initiation of embryogenesis in higher plants remains to be determined. LEAFY COTYLEDON1 (LEC1) is an important factor in early embryogenesis and is ectopically expressed in the pkl1-1 mutant, which is deficient in chromatin remodeling factor. Therefore, there is a high probability that chromatin remodeling regulates the expression of LEC1. To confirm this possibility, the histone methylation level, which is involved in chromatin remodeling, was examined for the genomic region of LEC1 by chromatin immunoprecipitation analysis. In the promoter region of LEC1, methylation of histone H3 lysine 4 in somatic embryos was higher in rosette leaves. SET domain-containing proteins are an important factor in histone methylation. To isolate the SET domain-containing protein genes (SET gene) involved in Arabidopsis thaliana embryogenesis, expression analyses using RT-PCR were performed. Among 37 SET genes, seven were found to have a high probability of involvement in embryogenesis.