Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis

0459908 - ÚEB 2017 RIV GB eng J - Journal Article
Grosskinsky, D. K. - Tafner, R. - Moreno, M. V. - Stenglein, S. A. - Garcia de Salamone, I. E. - Nelson, L. M. - Novák, Ondřej - Strnad, Miroslav - van der Graaff, E. - Roitsch, Thomas
Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis.
Scientific Reports. Roč. 6, MAR 17 (2016), s. 23310. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA MŠMT(CZ) LO1204; GA ČR GA15-22322S; GA MŠMT(CZ) LO1415
Institutional support: RVO:61389030 ; RVO:67179843
Keywords : GROWTH-PROMOTING RHIZOBACTERIA * PLANT-GROWTH * SALICYLIC-ACID
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 4.259, year: 2016

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience.
Permanent Link: http://hdl.handle.net/11104/0260064