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Biological control of bacterial wilt in Arabidopsis thaliana involves abscissic acid signalling
Author(s) -
Feng Dong Xin,
Tasset Céline,
Hanemian Mathieu,
Barlet Xavier,
Hu Jian,
Trémousaygue Dominique,
Deslandes Laurent,
Marco Yves
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2012.04113.x
Subject(s) - ralstonia solanacearum , bacterial wilt , biology , jasmonic acid , mutant , arabidopsis thaliana , microbiology and biotechnology , salicylic acid , arabidopsis , strain (injury) , inoculation , gene , pathogen , genetics , horticulture , anatomy
Summary• Means to control bacterial wilt caused by the phytopathogenic root bacteria Ralstonia solanacearum are limited. Mutants in a large cluster of genes ( hrp ) involved in the pathogenicity of R. solanacearum were successfully used in a previous study as endophytic biocontrol agents in challenge inoculation experiments on tomato. However, the molecular mechanisms controlling this resistance remained unknown. • We developed a protection assay using Arabidopsis thaliana as a model plant and analyzed the events underlying the biological control by genetic, transcriptomic and molecular approaches. • High protection rates associated with a significant decrease in the multiplication of R. solanacearum were observed in plants pre‐inoculated with a Δ hrpB mutant strain. Neither salicylic acid, nor jasmonic acid/ethylene played a role in the establishment of this resistance. Microarray analysis showed that 26% of the up‐regulated genes in protected plants are involved in the biosynthesis and signalling of abscissic acid (ABA). In addition 21% of these genes are constitutively expressed in the irregular xylem cellulose synthase mutants ( irx ), which present a high level of resistance to R. solanacearum . • We propose that inoculation with the Δ hrpB mutant strain generates a hostile environment for subsequent plant colonization by a virulent strain of R. solanacearum .