The Arabidopsis homolog of human G3BP1 is a key regulator of stomatal and apoplastic immunity

Aala Abulfaraj , Kiruthiga Mariappan , Jean Bigeard (1) , Prabhu Manickam , Ikram Blilou (2) , Xiujie Guo , Salim Al-Babili (3) , Delphine Pflieger (4) , Heribert Hirt (1) , Naganand Rayapuram

1 IPS2 (UMR_9213 / UMR_1403) - Institut des Sciences des Plantes de Paris-Saclay
2 Plant Development Biology
3 Cell Biology
4 EDyP - Etude de la dynamique des protéomes

Mammalian Ras-GTPase-activating protein SH3-domain-binding proteins (G3BPs) are a highly conserved family of RNA-binding proteins that link kinase receptor-mediated signaling to RNA metabolism. Mammalian G3BP1 is a multifunctional protein that functions in viral immunity. Here, we show that the Arabidopsis thaliana homolog of human G3BP1 negatively regulates plant immunity. Arabidopsis g3bp1 mutants showed enhanced resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato. Pathogen resistance was mediated in Atg3bp1 mutants by altered stomatal and apoplastic immunity. Atg3bp1 mutants restricted pathogen entry into stomates showing insensitivity to bacterial coronatine-mediated stomatal reopening. AtG3BP1 was identified as a negative regulator of defense responses, which correlated with moderate up-regulation of salicylic acid biosynthesis and signaling without growth penalty.

Mots clés: involvement; oxidative burst; signaling cascade; enboribonuclease g3bp; defense responses; salicylic-acid; systemic acquired-resistance; transcription; mosaic-virus; stress granules

Domaines: Génomique, Transcriptomique et Protéomique [q-bio.GN]

Aala Abulfaraj, Kiruthiga Mariappan, Jean Bigeard, Prabhu Manickam, Ikram Blilou, et al.. The Arabidopsis homolog of human G3BP1 is a key regulator of stomatal and apoplastic immunity. Life Science Alliance, 2018, 1 (2), pp.e201800046. ⟨10.26508/lsa.201800046⟩. ⟨hal-02083410⟩