LEC2 induces somatic embryogenesis through DNA-methylation-mediated activation of regulators plant cell totipotency regulator (PRJCA033386)

Many plant species can develop embryos from somatic cells without fertilization. During this process, known as somatic embryogenesis, changes in the DNA methylation patterns and reprogramming of gene expression have emerged as critical factors. However, the underlying mechanisms connecting DNA methylation and regulation of gene expression have remained largely unknown. Here, we show that during somatic embryogenesis induced by overexpressing the transcription factor LEC2 in Arabidopsis, CHH hypermethylation is deposited by LEC2-activated RNA-directed DNA methylation (RdDM) pathways. A SUVH-SDJ reader complex binds to the CHH hypermethylation regions and recruits AHL chromatin modification proteins to increase chromatin accessibility, resulting in the transcriptional activation of cell totipotency-regulating genes. Our work reveals a molecular framework of how epigenetic modifications mediate somatic cell reprogramming, offering a pathway toward enhancing somatic embryogenesis in agricultural regeneration biology.