Histone H3 Dynamics Reveal Domains with Distinct Proliferation Potential in the Arabidopsis Root. Issue 6 (20th May 2016)

• Record Type: Journal Article
• Authors: Otero, Sofía; Desvoyes, Bénédicte; Peiró, Ramón; Gutierrez, Crisanto
• Is Part Of: The Plant Cell. Volume 28:Issue 6(2016)
• Page Start: 1361
• Page End: 1371
• Publication Date: 2016-05-20
• DOI: 10.1105/tpc.15.01003
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : The dynamics of histones H3.1 and H3.3 characterize cells with different division potential in the growing root and a longer G2 phase in cells undergoing the last cell cycle before differentiation. Abstract: A coordinated transition from cell proliferation to differentiation is crucial for organogenesis. We found that extensive chromatin reorganization, shown here for histone H3 proteins, characterizes cell population dynamics in the root developmental compartments. The canonical H3.1 protein, incorporated during S-phase, is maintained at high levels in cells dividing at a high rate but is massively evicted in cells undergoing their last cell cycle before exit to differentiation. A similar pattern was observed in the quadruple mutant for the H3.1-encoding genes HTR1, HTR2, HTR3, and HTR9 ( htr1, 2, 3, 9 ), in which H3.1 is expressed only from the HTR13 gene. H3 eviction is a fast process occurring within the G2 phase of the last cell cycle, which is longer than G2 in earlier cell cycles. This longer G2 likely contributes to lower the H3.1/H3.3 ratio in cells leaving the root meristem. The high H3.1/H3.3 ratio and H3.1 eviction process also occurs in endocycling cells before differentiation, revealing a common principle of H3 eviction in the proliferating and endocycling domains of the root apex. Mutants in the H3.1 chaperone CAF-1 ( fas1-4 ) maintain a pattern similar to that of wild-type roots. Our studies reveal that H3 incorporation and eviction dynamics identify cells with different cell division potential during organ patterning.