Physiological effects of major up-regulated Alnus glutinosa peptides on Frankia sp. ACN14a

Lorena Carro Garcia (1, 2) , Petar Pujic (1) , Nicole Alloisio (1) , Pascale Fournier (1) , Hasna Boubakri (1, 3, 4) , Franck Poly (1) , Marjolaine Rey (5) , Abdelaziz Heddi (5) , Philippe Normand (1)

1 LEM - Laboratoire d'Ecologie Microbienne - UMR 5557
2 School of Biology
3 CNRS - Centre National de la Recherche Scientifique
4 UCBL - Université Claude Bernard Lyon 1
5 BF2I - Biologie Fonctionnelle, Insectes et Interactions

Alnus glutinosa has been shown previously to synthesize, in response to nodulation by Frankia sp. ACN14a, an array of peptides called Alnus symbiotic up-regulated peptides (ASUPs). In a previous study one peptide (Ag5) was shown to bind to Frankia nitrogen-fixing vesicles and to modify their porosity. Here we analyse four other ASUPs, alongside Ag5, to determine whether they have different physiological effects on in vitro grown Frankia sp. ACN14a. The five studied peptides were shown to have different effects on nitrogen fixation, respiration, growth, the release of ions and amino acids, as well as on cell clumping and cell lysis. The mRNA abundance for all five peptides was quantified in symbiotic nodules and one (Ag11) was found to be more abundant in the meristem part of the nodule. These findings point to some peptides having complementary effects on Frankia cells.

Mots clés: nitrogen fixation; defensin; symbiosis; amino acid; phylogeny

Mots clés: acide aminé; fixation de l'azote; peptide; symbiose; respiration; phylogénie

Domaines: Sciences du Vivant [q-bio]

Lorena Carro Garcia, Petar Pujic, Nicole Alloisio, Pascale Fournier, Hasna Boubakri, et al.. Physiological effects of major up-regulated Alnus glutinosa peptides on Frankia sp. ACN14a. Microbiology, 2016, 162 (7), pp.1173-1184. ⟨10.1099/mic.0.000291⟩. ⟨hal-01606507⟩