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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #322372
Title: A DEMETER-like DNA demethylase governs tomato fruit ripening

Author
item LIU, RUIE - University Of Bordeaux
item HOW-KIT, ALEXANDRE - University Of Bordeaux
item STAMMITTI, LINDA - University Of Bordeaux
item TEYSSIER, EMELINE - University Of Bordeaux
item ROLIN, DOMINIQUE - University Of Bordeaux
item HALLE, STEFANIE - University Of Bordeaux
item Giovannoni, James
item GALLUSCI, PHILIPPE - University Of Bordeaux

Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2015
Publication Date: 8/25/2015
Citation: Liu, R., How-Kit, A., Stammitti, L., Teyssier, E., Rolin, D., Halle, S., Giovannoni, J.J., Gallusci, P. 2015. A DEMETER-like DNA demethylase governs tomato fruit ripening. Proceedings of the National Academy of Sciences. 112:10804-10809.

Interpretive Summary: In plants, DNA Glycosylase Lyases (DNAGL) also called DEMETER-Like (DML) proteins are involved in active DNA demethylation and have been associated with endosperm imprinting, global demethylation of the endosperm and the removal of improper methylation. Yet their physiological role remains largely unknown. Here we show that DMLs govern tomato fruit ripening and most likely other aspects of plant development. Tomato RNAi lines with reduced DML expression develop fruits with delayed and partial ripening. In these fruits, the expression of genes that either control (RIN, NOR, CNR) or are involved (PSY1) in the ripening process is extremely delayed and reduced. Indeed, the promoter region of these genes remained methylated in the fruits of the DML RNAi lines whereas it is demethylated in wild type (WT) fruits. Our results demonstrate that active DNA demethylation is an essential component of the regulatory cascade controlling fruit ripening but may also be involved in other aspects of plant development including leaf shape and flower development. The results are the foundation of a new paradigm where epigenetic regulatory pathways are central to the regulation of fruit ripening and are consistent with genomic demethylation having a previously unrecognized but important role in plant developmental processes.

Technical Abstract: This work shows that active DNA demethylation governs ripening, an important plant developmental process. Our work defines a molecular mechanism, which has until now been missing, to explain the correlation between genomic DNA demethylation and fruit ripening. It demonstrates a direct cause-and-effect relationship between active DNA demethylation and induction of gene expression in fruits. The importance of these findings goes far beyond understanding the developmental biology of ripening and provides an innovative strategy for its fine control through fine modulation of epimarks in the promoters of ripening related genes. Our results have significant application for plant breeding especially in species with limited available genetic variation.