Differential Methylation during Maize Leaf Growth Targets Developmentally Regulated Genes      . Issue 3 (31st January 2014)

• Record Type: Journal Article
• Authors: Candaele, Jasper; Demuynck, Kirin; Mosoti, Douglas; Beemster, Gerrit T.S.; Inzé, Dirk; Nelissen, Hilde
• Is Part Of: Plant physiology. Volume 164:Issue 3(2014)
• Page Start: 1350
• Page End: 1364
• Publication Date: 2014-01-31
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.113.233312
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : The successive growth processes of cell division and cell elongation in maize leaves are characterized by differential DNA methylation that is correlated with differential expression . Abstract: DNA methylation is an important and widespread epigenetic modification in plant genomes, mediated by DNA methyltransferases (DMT s). DNA methylation is known to play a role in genome protection, regulation of gene expression, and splicing and was previously associated with major developmental reprogramming in plants, such as vernalization and transition to flowering. Here, we show that DNA methylation also controls the growth processes of cell division and cell expansion within a growing organ. The maize ( Zea mays ) leaf offers a great tool to study growth processes, as the cells progressively move through the spatial gradient encompassing the division zone, transition zone, elongation zone, and mature zone. Opposite to de novo DMT s, the maintenance DMT s were transcriptionally regulated throughout the growth zone of the maize leaf, concomitant with differential CCGG methylation levels in the four zones. Surprisingly, the majority of differentially methylated sequences mapped on or close to gene bodies and not to repeat-rich loci. Moreover, especially the 5′ and 3′ regions of genes, which show overall low methylation levels, underwent differential methylation in a developmental context. Genes involved in processes such as chromatin remodeling, cell cycle progression, and growth regulation, were differentially methylated. The presence of differential methylation located upstream of the gene anticorrelated with transcript expression, while gene body differential methylation was unrelated to the expression level. These data indicate that DNA methylation is correlated with the decision to exit mitotic cell division and to enter cell expansion, which adds a new epigenetic level to the regulation of growth processes.