Looking at plant cell cycle from the chromatin window

Abstract

The cell cycle is defined by a series of complex events, finely coordinated through hormonal, developmental and environmental signals, which occur in a unidirectional manner and end up in producing two daughter cells. Accumulating evidence reveals that chromatin is not a static entity throughout the cell cycle. In fact, there are many changes that include nucleosome remodeling, histone modifications, deposition and exchange, among others. Interestingly, it is possible to correlate the occurrence of several of these chromatin-related events with specific processes necessary for cell cycle progression, e.g., licensing of DNA replication origins, the E2F-dependent transcriptional wave in G1, the activation of replication origins in S-phase, the G2-specific transcription of genes required for mitosis or the chromatin packaging occurring in mitosis. Therefore, an emerging view is that chromatin dynamics must be considered as an intrinsic part of cell cycle regulation. In this article, we review the main features of several key chromatin events that occur at defined times throughout the cell cycle and discuss whether they are actually controlling the transit through specific cell cycle stages.

Histone H2A/H2B chaperones: from molecules to chromatin‐based functions in plant growth and development

“…Histone incorporation into chromatin is critical for genome replication, because random transfer of parental histones is not sufficient to meet the requirement for packaging the duplicated nascent daughter DNA strands. Histone chaperones that escort histones from the cytoplasm to the nucleus and further assist nucleosome assembly are considered to play important roles in completion of genome duplication during the S phase of the cell cycle (Ransom et al ., ; Avvakumov et al ., ; Desvoyes et al ., ; Raynaud et al ., ). The in vitro formation of regularly spaced nucleosomes on DNA requires synergistic action of NAP1 with other chromatin factors such as CAF–1 (Ito et al ., ).…”

“…Chromatin composition and structure determine all DNA‐based processes, and mutually dynamic nucleosome assembly/disassembly/reassembly are associated with transcription, DNA replication and repair (Ransom et al ., ; Avvakumov et al ., ; Zhu et al ., ; Desvoyes et al ., ; Raynaud et al ., ; Van Lijsebettens and Grasser, ). Because of the intrinsic strong electrostatic interactions between DNA and histone molecules, the ordered formation of the nucleosome structure at physiological ionic strength conditions requires participation of histone chaperones.…”

Mitotic lifecycle of chromosomal 3xHMG‐box proteins and the role of their N‐terminal domain in the association with rDNA loci and proteolysis

“…The condensin complex is a central player in mitotic chromosome compaction and its subunits are conserved in Arabidopsis (Schubert, 2009;Hirano, 2012). Even though mitotic chromosome compaction and segregation are presumably the most obvious and easily observable DNA-related events, little is known about the molecular proceeding of these processes and their regulation in plants (Tiang et al, 2012;Raynaud et al, 2014;Desvoyes et al, 2015) and it remains to be seen if 3xHMG-box proteins possibly cooperate with the condensins during mitosis. Another attractive potential role of 3xHMG-box proteins in connection with linker histone H1 was proposed by Jerzmanowski & Kotlinski (2011).…”

ABCB19‐mediated polar auxin transport modulates Arabidopsis hypocotyl elongation and the endoreplication variant of the cell cycle

“…Despite recent major advances in understanding auxin receptor‐mediated signaling (Bargmann and Estelle, ) and the participation of small auxin up‐regulated RNAs in auxin action (Chae et al ., ; Spartz et al ., ), it is still not clear how auxin controls hypocotyl growth. Unlike the growth of leaves or roots, which depends on the production of new cells by a tightly controlled cell cycle (De Veylder et al ., ; Gutierrez, ; Desvoyes et al ., ), hypocotyl cells rarely undergo mitosis except in the few epidermal cells that produce stomata (Gendreau et al ., ). Post‐germination growth is essentially a manifestation of cell expansion.…”