PT  - JOURNAL ARTICLE
AU  - van de Mortel, Judith E.
AU  - de Vos, Ric C.H.
AU  - Dekkers, Ester
AU  - Pineda, Ana
AU  - Guillod, Leandre
AU  - Bouwmeester, Klaas
AU  - van Loon, Joop J.A.
AU  - Dicke, Marcel
AU  - Raaijmakers, Jos M.
TI  - Metabolic and Transcriptomic Changes Induced in Arabidopsis by the Rhizobacterium <em>Pseudomonas fluorescens</em> SS101
AID  - 10.1104/pp.112.207324
DP  - 2012 Dec 01
TA  - Plant Physiology
PG  - 2173--2188
VI  - 160
IP  - 4
4099  - http://www.plantphysiol.org/content/160/4/2173.short
4100  - http://www.plantphysiol.org/content/160/4/2173.full
SO  - Plant Physiol.2012 Dec 01; 160
AB  - Systemic resistance induced in plants by nonpathogenic rhizobacteria is typically effective against multiple pathogens. Here, we show that root-colonizing Pseudomonas fluorescens strain SS101 (Pf.SS101) enhanced resistance in Arabidopsis (Arabidopsis thaliana) against several bacterial pathogens, including Pseudomonas syringae pv tomato (Pst) and the insect pest Spodoptera exigua. Transcriptomic analysis and bioassays with specific Arabidopsis mutants revealed that, unlike many other rhizobacteria, the Pf.SS101-induced resistance response to Pst is dependent on salicylic acid signaling and not on jasmonic acid and ethylene signaling. Genome-wide transcriptomic and untargeted metabolomic analyses showed that in roots and leaves of Arabidopsis plants treated with Pf.SS101, approximately 1,910 genes and 50 metabolites were differentially regulated relative to untreated plants. Integration of both sets of “omics” data pointed to a prominent role of camalexin and glucosinolates in the Pf.SS101-induced resistance response. Subsequent bioassays with seven Arabidopsis mutants (myb51, cyp79B2cyp79B3, cyp81F2, pen2, cyp71A12, cyp71A13, and myb28myb29) disrupted in the biosynthesis pathways for these plant secondary metabolites showed that camalexin and glucosinolates are indeed required for the induction of Pst resistance by Pf.SS101. Also for the insect S. exigua, the indolic glucosinolates appeared to play a role in the Pf.SS101-induced resistance response. This study provides, to our knowledge for the first time, insight into the substantial biochemical and temporal transcriptional changes in Arabidopsis associated with the salicylic acid-dependent resistance response induced by specific rhizobacteria.GlossarySARsystemic acquired resistanceISRinduced systemic resistancePGPRplant growth-promoting rhizobacteriaJAjasmonic acidETethyleneSAsalicylic acidPf.SS101Pseudomonas fluorescens SS101PstPseudomonas syringae pv tomatoCFUcolony-forming unitsCol-0ColumbiaPf.WCS417rPseudomonas fluorescens strain WCS417rDPIdays post inoculationORAoverrepresentation analysisLCliquid chromatographyMSmass spectrometryTTSStype III secretion systemPAMPpathogen-associated molecular patternKBKing’s medium BGLMgeneralized linear modelRQrelative quantificationCTthreshold cycleQTOFquadrupole time-of-flight