Insight into a meiotic role of the major histone H3 lysine 4 methyltransferase in Arabidopsis

Arabidopsis genome encodes at least 40 histone methyltransferase and only a few of them have been extensively studied. Recently , Berr and colleagues reported SDG2 as the major histone H3 Lysine 4 methyltransferase in Arabidopsis. Indeed, sdg2 lines show pleiotropic defects both at sporophytic and gametophytic level influencing plant size, cell cycle and the development of pollen, ovule and embryo. Among the reproductive anomalies affecting sdg2 mutant, Berr and colleagues reported a female sterility and the formation of triads, dyads and monads at the end of male meiosis. By performing microarray on premeiotic buds Berr and colleagues found a relationship between the gamethophytic defects and the missregulation of known gametophytic genes. However, no hypothesis was made about the causes of meiotic product defects. A further analysis of the microarray data from Berr and collegues was performed in this study in order to get new insights into SDG2 activity. We highlights the possible contribution of two meiotic genes to sdg2 phenotype. Moreover, based on the high number of differentially expressed genes, we confirm that SDG2 is a master regulator of transcription whose effect can be dependent directely on the histone methylation and /or indirectely through the histone acetylation.