TY - JOUR
T1 - Role of the GacS sensor kinase in the regulation of volatile production by plant growth-promoting Pseudomonas fluorescens SBW25
AU - Cheng, Xu
AU - Cordovez, Viviane
AU - Etalo, Desalegn W.
AU - van der Voort, M.
AU - Raaijmakers, Jos M.
PY - 2016/11/18
Y1 - 2016/11/18
N2 - In plant-associated Pseudomonas species,the production of several secondary metabolites and exoenzymes is regulated by the GacS/GacA two-component regulatory system (the Gac-system). Here,we investigated if a mutation in the GacS sensor kinase affects the production of volatile organic compounds (VOCs) in P. fluorescens SBW25 (Pf.SBW25) and how this impacts on VOCs-mediated growth promotion and induced systemic resistance of Arabidopsis and tobacco. A total of 205 VOCs were detected by Gas Chromatography Mass Spectrometry for Pf. SBW25 and the gacS-mutant grown on two different media for 3 and 6 days. Discriminant function analysis followed by hierarchical clustering revealed 24 VOCs that were significantly different in their abundance between Pf.SBW25 and the gacS-mutant,which included three acyclic alkenes (3-nonene,4-undecyne,1-undecene). These alkenes were significantly reduced by the gacS mutation independently of the growth media and of the incubation time. For Arabidopsis,both Pf.SBW25 and the gacS-mutant enhanced,via VOCs,root and shoot biomass,induced systemic resistance against leaf infections by P. syringae and rhizosphere acidification to the same extent. For tobacco,however,VOCs-mediated effects on shoot and root growth were significantly different between Pf.SBW25 and the gacS-mutant. While Pf.SBW25 inhibited tobacco root growth,the gacS-mutant enhanced root biomass and lateral root formation relative to the non-treated control plants. Collectively these results indicate that the sensor kinase GacS is involved in the regulation of VOCs production in Pf.SBW25,affecting plant growth in a plant species-dependent manner.
AB - In plant-associated Pseudomonas species,the production of several secondary metabolites and exoenzymes is regulated by the GacS/GacA two-component regulatory system (the Gac-system). Here,we investigated if a mutation in the GacS sensor kinase affects the production of volatile organic compounds (VOCs) in P. fluorescens SBW25 (Pf.SBW25) and how this impacts on VOCs-mediated growth promotion and induced systemic resistance of Arabidopsis and tobacco. A total of 205 VOCs were detected by Gas Chromatography Mass Spectrometry for Pf. SBW25 and the gacS-mutant grown on two different media for 3 and 6 days. Discriminant function analysis followed by hierarchical clustering revealed 24 VOCs that were significantly different in their abundance between Pf.SBW25 and the gacS-mutant,which included three acyclic alkenes (3-nonene,4-undecyne,1-undecene). These alkenes were significantly reduced by the gacS mutation independently of the growth media and of the incubation time. For Arabidopsis,both Pf.SBW25 and the gacS-mutant enhanced,via VOCs,root and shoot biomass,induced systemic resistance against leaf infections by P. syringae and rhizosphere acidification to the same extent. For tobacco,however,VOCs-mediated effects on shoot and root growth were significantly different between Pf.SBW25 and the gacS-mutant. While Pf.SBW25 inhibited tobacco root growth,the gacS-mutant enhanced root biomass and lateral root formation relative to the non-treated control plants. Collectively these results indicate that the sensor kinase GacS is involved in the regulation of VOCs production in Pf.SBW25,affecting plant growth in a plant species-dependent manner.
KW - GC-MS
KW - ISR
KW - Plant growth promotion
KW - Pseudomonas
KW - Two-component regulation
KW - Volatile organic compounds
U2 - 10.3389/fpls.2016.01706
DO - 10.3389/fpls.2016.01706
M3 - Article
AN - SCOPUS:84996480142
VL - 7
JO - Frontiers in Plant Science
JF - Frontiers in Plant Science
SN - 1664-462X
M1 - 1706
ER -