Open AccessThe phytopathogen Rhodococcus fascians breaks apical dominance and activates axillary meristems by inducing plant genes involved in hormone metabolism
Author(s) -
SIMÓNMATEO CARMEN,
DEPUYDT STEPHEN,
DE OLIVEIRA MANES CARMEM LARA,
CNUDDE FILIP,
HOLSTERS MARCELLE,
GOETHALS KOEN,
VEREECKE DANNY
Publication year - 2006
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/j.1364-3703.2006.00322.x
Subject(s) - biology , meristem , arabidopsis , plant hormone , gibberellin , apical dominance , axillary bud , gene , auxin , microbiology and biotechnology , abscisic acid , genetics , botany , mutant , shoot , explant culture , in vitro
SUMMARY Rhodococcus fascians is a Gram‐positive bacterium that interacts with many plant species and induces multiple shoots through a combination of activation of dormant axillary meristems and de novo meristem formation. Although phenotypic analysis of the symptoms of infected plants clearly demonstrates a disturbance of the phytohormonal balance and an activation of the cell cycle, the actual mechanism of symptom development and the targets of the bacterial signals are unknown. To elucidate the molecular pathways that are responsive to R. fascians infection, differential display was performed on Nicotiana tabacum as a host. Four differentially expressed genes could be identified that putatively encode a senescence‐associated protein, a gibberellin 2‐oxidase, a P450 monooxygenase and a proline dehydrogenase. The differential expression of the three latter genes was confirmed on infected Arabidopsis thaliana plants by quantitative reverse transcription polymerase chain reactions, supporting their general function in R. fascians ‐induced symptom development. The role of these genes in hormone metabolism, especially of gibberellin and abscisic acid, in breaking apical dominance and in activating axillary meristems, which are processes associated with symptom development, is discussed.