DELLAs Regulate Chlorophyll and Carotenoid Biosynthesis to Prevent Photooxidative Damage during Seedling Deetiolation in Arabidopsis

TitreDELLAs Regulate Chlorophyll and Carotenoid Biosynthesis to Prevent Photooxidative Damage during Seedling Deetiolation in Arabidopsis
Type de publicationArticle de revue
AuteurCheminant, Soizic, Wild, Michael, Bouvier, Florence, Pelletier, Sandra, Renou, Jean-Pierre , Erhardt, Mathieu, Hayes, Scott, Terry, Matthew J, Genschik, Pascal, Achard, Patrick
EditeurAmerican Society of Plant Biologists
TypeArticle scientifique dans une revue à comité de lecture
Année2011
LangueAnglais
Date2011/05/01
Numéro5
Pagination1849 - 1860
Volume23
Titre de la revueThe Plant Cell Online
ISSN1040-4651
Résumé en anglais

In plants, light represents an important environmental signal that triggers the production of photosynthetically active chloroplasts. This developmental switch is critical for plant survival because chlorophyll precursors that accumulate in darkness can be extremely destructive when illuminated. Thus, plants have evolved mechanisms to adaptively control plastid development during the transition into light. Here, we report that the gibberellin (GA)-regulated DELLA proteins play a crucial role in the formation of functional chloroplasts during deetiolation. We show that Arabidopsis thaliana DELLAs accumulating in etiolated cotyledons derepress chlorophyll and carotenoid biosynthetic pathways in the dark by repressing the transcriptional activity of the phytochrome-interacting factor proteins. Accordingly, dark-grown GA-deficient ga1-3 mutants (that accumulate DELLAs) display a similar gene expression pattern to wild-type seedlings grown in the light. Consistent with this, ga1-3 seedlings accumulate higher amounts of protochlorophyllide (a phototoxic chlorophyll precursor) in darkness but, surprisingly, are substantially more resistant to photooxidative damage following transfer into light. This is due to the DELLA-dependent upregulation of the photoprotective enzyme protochlorophyllide oxidoreductase (POR) in the dark. Our results emphasize the role of DELLAs in regulating the levels of POR, protochlorophyllide, and carotenoids in the dark and in protecting etiolated seedlings against photooxidative damage during initial light exposure.

URL de la noticehttp://okina.univ-angers.fr/publications/ua7734
DOI10.1105/tpc.111.085233
Lien vers le document

http://dx.doi.org/10.1105/tpc.111.085233