Open AccessQuantification of induced resistance against Phytophthora species expressing GFP as a vital marker: β‐aminobutyric acid but not BTH protects potato and Arabidopsis from infection
Author(s) -
SiAmmour Azeddine,
MauchMani Brigitte,
Mauch Felix
Publication year - 2003
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 - 10.1046/j.1364-3703.2003.00168.x
Subject(s) - biology , phytophthora infestans , pathosystem , arabidopsis , inoculation , gus reporter system , green fluorescent protein , botany , microbiology and biotechnology , blight , genetically modified crops , gene , horticulture , genetics , transgene , mutant
SUMMARY Induced resistance was studied in the model pathosystem Arabidopsis ‐ Phytophthora brassicae (formerly P. porri ) in comparison with the agronomically important late blight disease of potato caused by Phytophthora infestans . For the quantification of disease progress, both Phytophthora species were transformed with the vector p34GFN carrying the selectable marker gene neomycine phosphotransferase ( nptII ) and the reporter gene green fluorescent protein ( gfp ). Eighty five per cent of the transformants of P. brassicae and P. infestans constitutively expressed GFP at high levels at all developmental stages both in vitro and in planta . Transformants with high GFP expression and normal in vitro growth and virulence were selected to quantify pathogen growth by measuring the in planta emitted GFP fluorescence. This non‐destructive monitoring of the infection process was applied to analyse the efficacy of two chemical inducers of disease resistance, a functional SA‐analogue, benzothiadiazole (BTH), and β‐aminobutyric acid (BABA) which is involved in priming mechanisms of unknown nature. BABA pre‐treatment (300 µ m ) via soil drench applied 24 h before inoculation completely protected the susceptible Arabidopsis accession Landsberg erecta (Ler) from infection with P. brassicae . A similar treatment with BTH (330 µ m ) did not induce resistance. Spraying the susceptible potato cultivar Bintje with BABA (1 m m ) 2 days before inoculation resulted in a phenocopy of the incompatible interaction shown by the resistant potato cultivar Matilda while BTH (1.5 m m ) did not protect Bintje from severe infection. Thus, in both pathosystems, the mechanisms of induced resistance appeared to be similar, suggesting that the Arabidopsis ‐ P. brassicae pathosystem is a promising model for the molecular analysis of induced resistance mechanisms of potato against the late blight disease.