RT Journal Article SR Electronic T1 The Arabidopsis homolog of human G3BP1 is a key regulator of stomatal and apoplastic immunity JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e201800046 DO 10.26508/lsa.201800046 VO 1 IS 2 A1 Aala A Abulfaraj A1 Kiruthiga Mariappan A1 Jean Bigeard A1 Prabhu Manickam A1 Ikram Blilou A1 Xiujie Guo A1 Salim Al-Babili A1 Delphine Pflieger A1 Heribert Hirt A1 Naganand Rayapuram YR 2018 UL https://www.life-science-alliance.org/content/1/2/e201800046.abstract AB 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.