The Arabidopsis ISR1 Locus is Required for Rhizobacteria-Mediated Induced Systemic Resistance Against Different Pathogens

Abstract

In Arabidopsis thaliana, non-pathogenic, root-colonizing Pseudomonas fluorescens WCS417r bacteria trigger an induced systemic resistance (ISR) that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). In contrast to SAR, WCS417r-mediated ISR is controlled by a salicylic acid (SA)-independent signalling pathway that requires an intact response to the plant hormones jasmonic acid (JA) and ethylene (ET). Arabidopsis accessions RLD1 and Ws-0 fail to express ISR against Pseudomonas syringae pv. tomato and show enhanced disease susceptibility to this pathogen. Genetic analysis of progeny from crosses between WCS417r-responsive and non-responsive accessions demonstrated that ISR inducibility and basal resistance against P. syringae pv. tomato are controlled by a single dominant locus (ISR1) on chromosome III (Ton et al., 1999[8]). Here, we investigated the role of the ISR1 locus in ISR, SAR and basal resistance against three additional pathogens: Xanthomonas campestris pv. armoraciae, Peronospora parasitica and turnip crinkle virus (TCV), using accessions Col-0 (ISR1), RLD1 (isr1) and Ws-0 (isr1) as host plants.

Abbreviations

ISR: induced systemic resistance

SAR: systemic acquired resistance

SA: salicylic acid

JA: jasmonic acid

ET: ethylene

Key words

Arabidopsis - basal resistance - ethylene - induced systemic resistance - plant defence - Pseudomonas fluorescens - systemic acquired resistance

References

• 01 Kachroo,  P.,, Yoshioka,  K.,, Shah,  J.,, Dooner,  H. K.,, and Klessig,  D. F.. (2000);  Resistance to turnip crinkle virus in Arabidopsis is regulated by two host genes and is salicylic acid dependent but NPR1, ethylene and jasmonate independent.  Plant Cell. 12 677-690
• 02 Pieterse,  C. M. J.,, Van Pelt,  J. A.,, Van Wees,  S. C. M.,, Ton,  J.,, Léon-Kloosterziel,  K. M.,, Keurentjes,  J. J. B.,, Verhagen,  B. W. M.,, Knoester,  M.,, Van der Sluis,  I.,, Bakker,  P. A. H. M.,, and Van Loon,  L. C.. (2001);  Rhizobacteria-mediated induced systemic resistance: triggering, signalling and expression.  Eur. J. Plant Pathol.. 107 51-61
• 03 Pieterse,  C. M. J.,, Van Wees,  S. C. M.,, Hoffland,  E.,, Van Pelt,  J. A.,, and Van Loon,  L. C.. (1996);  Systemic resistance in Arabidopsis induced by biocontrol bacteria is independent of salicylic acid accumulation and pathogenesis-related gene expression.  Plant Cell. 8 1225-1237
• 04 Pieterse,  C. M. J.,, Van Wees,  S. C. M.,, Van Pelt,  J. A.,, Knoester,  M.,, Laan,  R.,, Gerrits,  H.,, Weisbeek,  P. J.,, and Van Loon,  L. C.. (1998);  A novel signaling pathway controlling induced systemic resistance in Arabidopsis. .  Plant Cell. 10 1571-1580
• 05 Ryals,  J. A.,, Neuenschwander,  U. H.,, Willits,  M. G.,, Molina,  A.,, Steiner,  H.,, and Hunt,  M. D.. (1996);  Systemic acquired resistance.  Plant Cell. 8 1809-1819
• 06 Sticher,  L.,, Mauch-Mani,  B.,, and Métraux,  J.-P.. (1997);  Systemic acquired resistance.  Annu. Rev. Phytopathol.. 35 235-270
• 07 Thomma,  B. P. H. J.,, Eggermont,  K.,, Penninckx,  I. A. M. A.,, Mauch-Mani,  B.,, Vogelsang,  R.,, Cammue,  B. P. A.,, and Broekaert,  W. F.. (1998);  Separate jasmonate-dependent and salicylate-dependent defense-response pathways in Arabidopsis are essential for resistance to distinct microbial pathogens.  Proc. Natl. Acad. Sci. USA. 95 15107-15111
• 08 Ton,  J.,, Pieterse,  C. M. J.,, and Van Loon,  L. C.. (1999);  Identification of a locus in Arabidopsis controlling both the expression of rhizobacteria-mediated induced systemic resistance (ISR) and basal resistance against Pseudomonas syringae pv. tomato. .  Mol. Plant-Microbe Interact.. 12 911-918
• 09 Ton,  J.,, Davison,  S.,, Van Wees,  S. C. M.,, Van Loon,  L. C.,, and Pieterse,  C. M. J.. (2001);  The ISR1 locus of Arabidopsis controlling induced systemic resistance is involved in ethylene signaling.  Plant Physiol.. 125 652-661
• 10 Ton,  J.,, Van Pelt,  J. A.,, Van Loon,  L. C.,, and Pieterse,  C. M. J.. (2002);  Differential effectiveness of salicylate-dependent, and jasmonate- and ethylene-dependent induced resistance in Arabidopsis. .  Mol. Plant-Microbe Interact.. 15 27-34
• 11 Van Loon,  L. C.,, Bakker,  P. A. H. M.,, and Pieterse,  C. M. J.. (1998);  Systemic resistance induced by rhizosphere bacteria.  Annu. Rev. Phytopathol.. 36 453-485
• 12 Van Wees,  S. C. M.,, Pieterse,  C. M. J.,, Trijssenaar,  A.,, Van't Westende,  Y. A. M.,, Hartog,  F.,, and Van Loon,  L. C.. (1997);  Differential induction of systemic resistance in Arabidopsis by biocontrol bacteria.  Mol. Plant-Microbe Interact.. 10 716-724
• 13 Van Wees,  S. C. M.,, De Swart,  E. A. M.,, Van Pelt,  J. A.,, Van Loon,  L. C.,, and Pieterse,  C. M. J.. (2000);  Enhancement of induced disease resistance by simultaneous activation of salicylate- and jasmonate-dependent defense pathways in Arabidopsis thaliana. .  Proc. Natl. Acad. Sci. USA. 95 1933-1937

Section Editor: J. Draper