Immunohistochemical study of DNA methylation dynamics during plant development

• Published in: Journal of experimental botany Vol. 52; no. 365; pp. 2265 - 2273
• Main Authors: Zluvova, Jitka, Janousek, Bohuslav, Vyskot, Boris
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-12-2001; OXFORD UNIVERSITY PRESS
• Subjects: Antibodies; Apical meristems; Biological and medical sciences; Cell and Molecular Biology, Biochemistry and Molecular Physiology; Cell Differentiation - physiology; Cell division; Cell Division - physiology; Cell Wall - metabolism; Cotyledon - growth & development; Cotyledon - metabolism; Cotyledon - ultrastructure; Cytosine - metabolism; DNA; DNA Methylation; DNA replication; DNA, Plant - metabolism; Fundamental and applied biological sciences. Psychology; Germination; Hypocotyl - growth & development; Hypocotyl - metabolism; Hypocotyl - ultrastructure; Hypocotyls; Immunohistochemistry; Meristem - growth & development; Meristem - metabolism; Meristem - ultrastructure; Meristems; Methylation; Molecular and cellular biology; Molecular genetics; Plant growth. Development of the storage organs; Plant physiology and development; Plants; seed germination; Seedlings; Seeds - genetics; Seeds - growth & development; Seeds - metabolism; shoot apical meristem; Silene - genetics; Silene - growth & development; Silene - metabolism; Silene latifolia; Transcription. Transcription factor. Splicing. Rna processing; Vegetative apparatus, growth and morphogenesis. Senescence; Immunohistochemistry; Weed; Transcription; Growth; Germination; Cell division; Tissue specificity; Gene expression; Time variation; Caryophyllaceae; Meristem; Regulation(control); Dicotyledones; DNA; Angiospermae; Replication; Spermatophyta; Developmental stage; Methylation
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jexbot/52.365.2265

DNA methylation represents one of the key processes that play an important role in the transcriptional control of gene expression. The role of cytosine methylation in plant development has been demonstrated by at least three different kinds of evidence: parent‐specific expression of some genes in developing seeds, control of flowering time and floral morphogenesis, and correlation with silencing of intrusive DNA sequences (mobile genetic elements and transgenes). In this work global changes in DNA methylation during seed germination and shoot apical meristem development in Silene latifolia have been studied using an indirect immunohistochemical approach. The data presented show that a rapid decrease in global DNA methylation during seed germination occurs first in endosperm tissue and subsequently in the hypocotyl. Using 5‐bromo‐2′‐deoxyuridine pulses, it has been demonstrated that these demethylation events occurred before cell division had begun. In the early post‐germination period, a decrease in DNA methylation was detected in cotyledons, also before cell division was observed. Taken together, these results indicate that DNA demethylation takes place in a non‐replicative way, probably by an active mechanism. The central zone of the shoot apical meristem remains highly methylated during the whole period of vegetative growth and in this region, only a low cell division activity was found. However, upon the transition of the shoot apical meristem to the floral bud, the meristem both decreased its high methylation status and its cells started to divide. These data indicate that the central zone of the shoot apical meristem can represent a relatively quiescent ‘germ‐line’ which is activated upon flowering to form spores and gametes.