Journal of Experimental Botany , Vol. 64, 63, No. No. 5, 2, pp. pp. 1153–1165, 695–709, 2012 2013 doi:10.1093/jxb/err313doi:10.1093/jxb/ers331 AdvanceAdvance AccessAccess publicationpublication 425 November, November 2011, 2012 This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details) RESEARCHDARWIN REVIEW PAPER InHormonalPosidonia regulation oceanica ofcadmium stem cell induces maintenance changes in roots in DNA methylation and chromatin patterning Yew Lee1, Woo Sung Lee2 and Soo-Hwan Kim1,* 1 MariaDivision Greco, of Biological Adriana Science Chiappetta, and Technology, Leonardo Yonsei BrunoUniversity, and Wonju Maria 220–710, Beatrice Republic Bitonti* of Korea 2 Department of Biological Science, Sungkyunkwan University, Suwon, 440–746, Republic of Korea Department of Ecology, University of Calabria, Laboratory of Plant Cyto-physiology, Ponte Pietro Bucci, I-87036 Arcavacata di Rende, Cosenza,* To whom Italy correspondence should be addressed. E-mail: [email protected] * To whom correspondence should be addressed. E-mail: [email protected] Received 19 April 2012; Revised 16 October 2012; Accepted 22 October 2012 Downloaded from Received 29 May 2011; Revised 8 July 2011; Accepted 18 August 2011 Abstract AbstractDuring plant embryogenesis, the apical–basal axis is established and both the shoot apical meristem (SAM) and the Inroot mammals, apical meristem cadmium (RAM) is widely are consideredformed. In both as a non-genotoxicmeristems, there carcinogen are slowly acting dividing through cells awhich methylation-dependent control the differ- http://jxb.oxfordjournals.org/ epigeneticentiation of mechanism. their surrounding Here, thecells effects called of the Cd organizing treatment centre on the (OC) DNA and methylation the quiescent patten centre are examined (QC) in the together shoot withand itsroot, effect respectively. on chromatin These reconfiguration centres with their in Posidoniasurrounding oceanica initial cells. DNA form methylation a ‘stem cell level niche’. and The pattern initial were cells analysed eventually in activelydifferentiate growing into organs,various underplant tissues, short- (6 giving h) and rise long- to plant (2 d or organs 4 d) term such and as lowlateral (10 shoots,mM) and flowers, high (50 leaves,mM) doses and oflateral Cd, throughroots. Plant a Methylation-Sensitivehormones are important Amplification factors involved Polymorphism in the balance technique between cell and division an immunocytological and differentiation approach, such that respectively.plant growth and The development expression of are one tightly member controlled of the inCHROMOMETHYLASE space and time. No single(CMT hormone) family, aacts DNA by methyltransferase,itself in regulating wasthe meristematic also assessed activity by qRT-PCR.in the root meristem. Nuclear chromatin Division and ultrastructure differentiation was are investigatedcontrolled by byinteractions transmission between electron sev- microscopy.eral hormones. Cd Intensive treatment research induced on a DNAplant hypermethylation,stem cells has focused as well on as how an cell up-regulation division is ofregulatedCMT, indicating to form specific that de novoplant organsmethylation and tissues, did indeed how differentiation occur. Moreover, is controlled, a high dose and ofhow Cd stem led cell to a fate progressive is coordinated. heterochromatinization In this review, recent of at Medical Sciences Library on May 27, 2016 interphaseknowledge nucleipertaining and apoptoticto the role figuresof plant were hormones also observed in maintaining after long-termroot stem treatment.cells including The the data QC demonstrate is summarized that and Cd perturbsdiscussed. the Furthermore, DNA methylation we suggest status diverse through approaches the involvement to answering of a specific the main methyltransferase. question of how root Such stem changes cells are linkedregulated to nuclearand maintained chromatin by plant reconfiguration hormones. likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants. Key words: Hormone cross-talk, plant hormone, quiescent centre, root apical meristem, root development, stem cell niche. Key words: 5-Methylcytosine-antibody, cadmium-stress condition, chromatin reconfiguration, CHROMOMETHYLASE, DNA-methylation, Methylation- Sensitive Amplification Polymorphism (MSAP), Posidonia oceanica (L.) Delile. Introduction IntroductionA root is formed from a reservoir of undifferentiated cells, on the effect of hormonal interactions. The possible involve- called root stem cells, in the root apical meristem (RAM). ment of non-hormonal factors that might interact with plant InPlant the hormones Mediterranean control coastalroot growth ecosystem, and development the endemic by hormonesAlthough through not essential cell–cell forcommunication plant growth, is also in discussed. terrestrial seagrassbalancingPosidonia between cell oceanica division(L.) and Delile differentiation, plays a relevant and their role plants,Furthermore, Cd is readily we suggest absorbed diverse by approaches roots and translocatedto answering into the byinteractions ensuring are primary crucial production,for the temporal water and oxygenation spatial coordina and- aerialmain question organs while, of how in root acquatic stem plants,cells are it regulated is directly and taken main up- providestion of root niches development. for some Six animals, classical plant besides hormones, counteracting auxin, bytained leaves. by plant In plants, hormones. Cd absorption induces complex changes coastalabscisic erosionacid (ABA), through brassinosteroids its widespread (BRs), meadows cytokinin (Ott, (CK), 1980; at the genetic, biochemical and physiological levels which Piazziethylene,et and al., 1999;gibberellins Alcoverro (GAs),et al.are, all 2001). involved There in is post- also ultimately account for its toxicity (Valle and Ulmer, 1972; considerableembryogenetic evidence root organogenesis that P. oceanica and regulateplants the are formation able to Sanit di Toppi and Gabrielli, 1999; Benavides et al., 2005; Structurez and organization of the root cell absorband maintenance and accumulate of the RAM. metals The from effects sediments of plant hormones (Sanchiz Weber et al., 2006; Liu et al., 2008). The most obvious etand al. the, 1990; regulating Pergent-Martini, proteins are 1998; discussed Maserti inet several al., 2005) reviews thus symptomThe Arabidopsis of Cd toxicity root has is a reductiona simple,in concentric plant growth structure due to influencinglargely based metal on genetic bioavailability and molecular in the studies marine (Benkova ecosystem. and an(Fig. inhibition 1; Dolan ofet photosynthesis, al., 1993). The radial respiration, pattern and of nitrogenthe root ForHejatko, this 2009 reason,; Depuydt this seagrass and Hardtke, is widely 2011 considered). In this review, to be metabolism,is composed asof wellthe outermost as a reduction lateral in root water cap, and epidermis, mineral awe metal discuss bioindicator the effect of species individual (Maserti hormoneset al., on 1988; the Pergentforma- uptakeground (Ouzonidoutissue (cortexet al.and, 1997; endodermis), Perfus-Barbeoch pericycle,et al.and, 2000; the ettion al. and, 1995; maintenance Lafabrie ofet the al. RAM,, 2007). especially Cd is onethe quiescent of most Shuklainnermostetal. stele., 2003; Along Sobkowiak the longitudinal and Deckert, axis, the 2003). root is com- widespreadcentre (QC) heavyand root metals stem incells, both and terrestrialdiscuss recent and findings marine posedAt theof a geneticlateral root level, cap, in columella, both animals QC and and initials/stem plants, Cd environments. can induce chromosomal aberrations, abnormalities in ª© 2011The Author The Author(s). [2012]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved. ThisFor permissions, is an Open Access please articleemail: [email protected] under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by- nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 1154 | Lee et al. Downloaded from http://jxb.oxfordjournals.org/ Fig. 1. Structure of the Arabidopsis root. (A) Schematic longitudinal section of the Arabidopsis root. There are three distinct developmental zones: the meristematic zone (MZ), the transition zone (TZ), and the elongation zone (EZ). The meristematic zone can be divided into the distal meristem (DM) and the proximal meristem (PM). In the meristematic zone, there is a ‘stem cell niche’ (SCN) that consists of the QC and initials (stem cells). (B) Schematic longitudinal section of the Arabidopsis root tip. The area enclosed with the red line shows the SCN. Around the QC, there are four initials (root stem cells). QC, quiescent centre (purple); CEI, cortex/endodermis initials (light green); ELRCI, epidermis/lateral root cap initials (light brown); CI, columella initials (sky blue); SI, stele initials (light ochre); LRC, lateral root cap (pink); EPI, epidermis (green); COR, cortex (light sky blue); ENDO, endodermis (dark ochre); STE, stele (dark brown. The same colours are used to represent the same tissues (or cells) in Fig. 2. at Medical Sciences Library on May 27, 2016 cells, proximal meristem, transition