DNA METHYLTRANSFERASE1‐mediated shoot regeneration is regulated by cytokinin‐induced cell cycle in Arabidopsis

Abstract

SummaryDNA methylation plays a critical role in diverse biological processes of plants. Arabidopsis DNA METHYLTRANSFERASE1 (MET1) represses shoot regeneration by inhibiting WUSCHEL (WUS) expression, which is essential for shoot initiation. However, the upstream signals regulating MET1 expression during this process are unclear.We analyzed the signals regulating MET1 expression using a number of established strategies, such as genetic analysis, confocal microscopy, quantitative real-time PCR and chromatin immunoprecipitation.MET1 expression patterns underwent dynamic changes with the initiation of WUS during shoot regeneration. The cell cycle regulator E2FA was characterized as an upstream factor directly promoting MET1 expression. Moreover, cytokinin promoted MET1 expression partially by enhancing CYCD3 expression.Our findings reveal that MET1-mediated shoot regeneration is regulated by the cytokinininduced cell cycle, and provide new insights into the regulation of DNA methylation in shoot regeneration.

Insight into the Role of Epigenetic Processes in Abiotic and Biotic Stress Response in Wheat and Barley

“…In plants, cytosine methylation is detected in the context of CG, CHG, and CHH (where H is any nucleotide except G) [28,29], in which CG is the most abundant and widespread methylation site [30]. It has been revealed that the DNA de novo C methylation in Arabidopsis is catalyzed by methyltransferase DOMAINS REARRANGED METHYLTRANFERASE 1 (DRM1) and DRM2 [29], while the maintenance of DNA methylation in mitosis and meiosis relies on the METHYLTRANSFERASE 1 (MET1) [31], CHROMOMETHYLASE 2/3 (CMT2/3) [27,31]. High-resolution DNA methylation profiling in Arabidopsis and rice revealed that DNA methylation could take place in many chromatin regions, including intergenic transposable elements (TE), gene promoters and even gene-body [32][33][34][35].…”

Phytohormone and Chromatin Crosstalk: The Missing Link For Developmental Plasticity?

“…Chromatin-modifying complexes target key phytohormone-regulated genes that specify meristem cell identity and whose ectopic expression can result in cell reprogramming and homeosis (Zuo et al, 2002; Galinha et al, 2007). For example, the SAM-organizing homeobox gene WUSCHEL ( WUS ) is regulated by cytokinin signaling, DNA methylation, H3K27me, or chromatin remodeling (Kwon, 2005; Dodsworth, 2009; Cao et al, 2015; Liu H. et al, 2018), and loss of DNA methylation in WUS promoter is connected to in-vitro shoot initiation induced by cytokinin (Li et al, 2011). Other stem cell niche-defining TFs such as WOX4, WOX5, PLT1 , or PLT2 are potential PRC2 targets (Oh et al, 2008; Lafos et al, 2011).…”

Global profiling of N6‐methyladenosine methylation in maize callus induction

“…In Arabidopsis, DNA hypermethylation suppresses the expression of the genes that block the cell state change, thereby influencing callus induction (Berdasco et al., 2008). In Arabidopsis, a loss‐of‐function mutation in the DNA methyltransferase MET1 prevents WUS expression and E2Fa ‐dependent cell cycle regulation (Liu, Zhang, Dong, Hao, & Zhang, 2018).…”