Carbon Dynamics, Development and Stress Responses in Arabidopsis: Involvement of the APL4 Subunit of ADP-Glucose Pyrophosphorylase (Starch Synthesis)

Cécile Sulmon (1) , Gwenola Gouesbet (1) , Fanny Ramel (1) , Francisco Cabello-Hurtado (1) , Christophe Penno (1) , Nicole Bechtold (2) , Ivan Couée (1) , Abdelhak El Amrani (1)

1 ECOBIO - Ecosystèmes, biodiversité, évolution [Rennes]
2 UR254 - Unité de Recherche en Génétique et Amélioration des Plantes

An Arabidopsis thaliana T-DNA insertional mutant was identified and characterized for enhanced tolerance to the singlet-oxygen-generating herbicide atrazine in comparison to wild-type. This enhanced atrazine tolerance mutant was shown to be affected in the promoter structure and in the regulation of expression of the APL4 isoform of ADP-glucose-pyrophosphorylase, a key enzyme of the starch biosynthesis pathway, thus resulting in decrease of APL4 mRNA levels. The impact of this regulatory mutation was confirmed by the analysis of an independent T-DNA insertional mutant also affected in the promoter of the APL4 gene. The resulting tissue-specific modifications of carbon partitioning in plantlets and the effects on plantlet growth and stress tolerance point out to specific and non-redundant roles of APL4 in root carbon dynamics, shoot-root relationships and sink regulations of photosynthesis. Given the effects of exogenous sugar treatments and of endogenous sugar levels on atrazine tolerance in wild-type Arabidopsis plantlets, atrazine tolerance of this apl4 mutant is discussed in terms of perception of carbon status and of investment of sugar allocation in xenobiotic and oxidative stress responses.

Mots clés: Arabidopsis; stress responses; ADP-glucose pyrophosphorylase; APL4 gene; atrazine tolerance; carbon

Domaines: Biodiversité et Ecologie

Cécile Sulmon, Gwenola Gouesbet, Fanny Ramel, Francisco Cabello-Hurtado, Christophe Penno, et al.. Carbon Dynamics, Development and Stress Responses in Arabidopsis: Involvement of the APL4 Subunit of ADP-Glucose Pyrophosphorylase (Starch Synthesis). PLoS ONE, 2011, 6 (11), pp.e26855. ⟨10.1371/journal.pone.0026855⟩. ⟨hal-00671124⟩