Premium
Induction of systemic resistance in tomato by N ‐acyl‐L‐homoserine lactone‐producing rhizosphere bacteria
Author(s) -
SCHUHEGGER REGINA,
IHRING ALEXANDRA,
GANTNER STEPHAN,
BAHNWEG GüNTHER,
KNAPPE CLAUDIA,
VOGG GERD,
HUTZLER PETER,
SCHMID MICHAEL,
VAN BREUSEGEM FRANK,
EBERL LEO,
HARTMANN ANTON,
LANGEBARTELS CHRISTIAN
Publication year - 2006
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2005.01471.x
Subject(s) - biology , rhizosphere , quorum sensing , microbiology and biotechnology , rhizobacteria , alternaria alternata , homoserine , bacteria , chitinase , salicylic acid , serratia , systemic acquired resistance , population , jasmonic acid , mutant , pseudomonas , biofilm , biochemistry , botany , gene , arabidopsis , genetics , demography , sociology
N ‐acyl‐L‐homoserine lactone (AHL) signal molecules are utilized by Gram‐negative bacteria to monitor their population density (quorum sensing) and to regulate gene expression in a density‐dependent manner. We show that Serratia liquefaciens MG1 and Pseudomonas putida IsoF colonize tomato roots, produce AHL in the rhizosphere and increase systemic resistance of tomato plants against the fungal leaf pathogen, Alternaria alternata . The AHL‐negative mutant S. liquefaciens MG44 was less effective in reducing symptoms and A. alternata growth as compared to the wild type. Salicylic acid (SA) levels were increased in leaves when AHL‐producing bacteria colonized the rhizosphere. No effects were observed when isogenic AHL‐negative mutant derivatives were used in these experiments. Furthermore, macroarray and Northern blot analysis revealed that AHL molecules systemically induce SA‐ and ethylene‐dependent defence genes (i.e. PR1a, 26 kDa acidic and 30 kDa basic chitinase). Together, these data support the view that AHL molecules play a role in the biocontrol activity of rhizobacteria through the induction of systemic resistance to pathogens.