Monteuuis O. auteur aut IRD Doulbeau Sylvie auteur aut IRD Verdeil J. L. auteur aut IRD text journalArticle eng text/pdf born digital access A meristem-issued rejuvenated line was obtained in 1986 from a 100-year-old Sequoiadendron giganteum tree and has been since then micropropagated in tissue culture conditions maintaining its juvenile-like characteristics. By contrast, grafts and rooted microcuttings from the same genotype planted in outdoor conditions for several years exhibited mature foliage traits and the grafts started to produce cones, which are obvious indicators of physiological aging. These three different clonal lines were compared with regard to global DNA methylation assessed by HPLC. The in vitro rejuvenated line showed a much higher level of DNA methylation (23% as average value) than the two other outdoor origins from the same clone which displayed similar degrees of global methylation (average values of 13.4% for the grafts and 13.8% for the cuttings). Overall these DNA global methylation values obtained for the first time in S. giganteum are consistent with the level of methylation reported for many plants using the same HPLC protocols. The fact that shoots exhibiting a juvenile-like leaf morphology can be characterized by higher DNA methylation than mature-like ones is discussed in relation to physiological aging, referring to other studies on the same topic. specialized Aging Coniferous species Dna methylation Maturational traits Phase change 076 22 6 779-784 2008 0931-1890 https://www.documentation.ird.fr/hor/fdi:010044130 10.1007/s00468-008-0238-3 0931-1890 [F B010044130] https://www.documentation.ird.fr/hor/fdi:010044130 https://www.documentation.ird.fr/intranet/publi/2008/12/010044130.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-01-09 2017-08-23 fdi:010044130 fre