Tranbarger Timothy auteur aut IRD Fooyontphanich K. auteur aut IRD Roongsattham P. auteur aut IRD Pizot M. auteur aut IRD Collin Myriam auteur aut IRD Jantasuriyarat C. auteur aut IRD Suraninpong P. auteur aut IRD Tragoonrung S. auteur aut IRD Dussert Stéphane auteur aut IRD Verdeil J. L. auteur aut IRD Morcillo F. auteur aut IRD text journalArticle eng text/pdf reformatted digital access The oil palm (Elaeis guineensis), a monocotyledonous species in the family Arecaceae, has an extraordinarily oil rich fleshy mesocarp, and presents an original model to examine the ripening processes and regulation in this particular monocot fruit. Histochemical analysis and cell parameter measurements revealed cell wall and middle lamella expansion and degradation during ripening and in response to ethylene. Cell wall related transcript profiles suggest a transition from synthesis to degradation is under transcriptional control during ripening, in particular a switch from cellulose, hemicellulose, and pectin synthesis to hydrolysis and degradation. The data provide evidence for the transcriptional activation of expansin, polygalacturonase, mannosidase, beta-galactosidase, and xyloglucan endotransglucosylase/hydrolase proteins in the ripening oil palm mesocarp, suggesting widespread conservation of these activities during ripening for monocotyledonous and eudicotyledonous fruit types. Profiling of the most abundant oil palm polygalacturonase (EgPG4) and 1-aminocyclopropane-1-carboxylic acid oxidase (AGO) transcripts during development and in response to ethylene demonstrated both are sensitive markers of ethylene production and inducible gene expression during mesocarp ripening, and provide evidence for a conserved regulatory module between ethylene and cell wall pectin degradation. A comprehensive analysis of NAG transcription factors confirmed at least 10 transcripts from diverse NAC domain clades are expressed in the mesocarp during ripening, four of which are induced by ethylene treatment, with the two most inducible (EgNAC6 and EgNAC7) phylogenetically similar to the tomato NAG-NOR master-ripening regulator. Overall, the results provide evidence that despite the phylogenetic distance of the oil palm within the family Arecaceae from the most extensively studied monocot banana fruit, it appears ripening of divergent monocot and eudicot fruit lineages are regulated by evolutionarily conserved molecular physiological processes. specialized ripening cell wall NAC domain oil palm monocotyledon mesocarp ethylene 076 8 art. 603 [12 p.] 2017 1664-462X https://www.documentation.ird.fr/hor/fdi:010069977 10.3389/fpls.2017.00603 1664-462X [F B010069977] https://www.documentation.ird.fr/hor/fdi:010069977 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-05/010069977.pdf IRD - Base Horizon / Pleins textes 2017-06-01 2023-07-11 fdi:010069977 fre