A guanosine tetraphosphate (ppGpp) mediated brake on photosynthesis is required for acclimation to nitrogen limitation in Arabidopsis
Shanna Romand,
Hela Abdelkefi,
Cécile Lecampion,
Mohamed Belaroussi,
Melanie Dussenne,
Brigitte Ksas,
Sylvie Citerne,
Jose Caius,
Stefano D'Alessandro,
Hatem Fakhfakh,
Stefano Caffarri,
Michel Havaux,
Ben Field
Affiliations
Shanna Romand
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Hela Abdelkefi
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France; University of Tunis El Manar, Faculty of Sciences of Tunis, Laboratory of Molecular Genetics, Immunology and Biotechnology, Tunis, Tunisia
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Mohamed Belaroussi
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Melanie Dussenne
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Brigitte Ksas
Aix-Marseille University, CEA, CNRS, BIAM, SAVE Team, Saint-Paul-lez-Durance, France
Sylvie Citerne
Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRAE Centre de Versailles-Grignon, Université Paris-Saclay, Versailles, France
Jose Caius
Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, France; Université de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, France
Stefano D'Alessandro
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Hatem Fakhfakh
University of Tunis El Manar, Faculty of Sciences of Tunis, Laboratory of Molecular Genetics, Immunology and Biotechnology, Tunis, Tunisia; University of Carthage, Faculty of Sciences of Bizerte, Bizerte, Tunisia
Stefano Caffarri
Aix-Marseille University, CEA, CNRS, BIAM, LGBP Team, Marseille, France
Michel Havaux
Aix-Marseille University, CEA, CNRS, BIAM, SAVE Team, Saint-Paul-lez-Durance, France
Guanosine pentaphosphate and tetraphosphate (together referred to as ppGpp) are hyperphosphorylated nucleotides found in bacteria and the chloroplasts of plants and algae. In plants and algae artificial ppGpp accumulation can inhibit chloroplast gene expression, and influence photosynthesis, nutrient remobilization, growth, and immunity. However, it is so far unknown whether ppGpp is required for abiotic stress acclimation in plants. Here, we demonstrate that ppGpp biosynthesis is necessary for acclimation to nitrogen starvation in Arabidopsis. We show that ppGpp is required for remodeling the photosynthetic electron transport chain to downregulate photosynthetic activity and for protection against oxidative stress. Furthermore, we demonstrate that ppGpp is required for coupling chloroplastic and nuclear gene expression during nitrogen starvation. Altogether, our work indicates that ppGpp is a pivotal regulator of chloroplast activity for stress acclimation in plants.
