The ethylene receptor ETR 1 is required for F usarium oxysporum pathogenicity

F usarium oxysporum is a ubiquitous vascular wilt plant pathogen causing severe yield losses in a wide range of economically important crops. In this study, the interaction between F usarium oxysporum f. sp. raphani and A rabidopsis thaliana plants impaired in the salicylate ( SA ), jasmonate ( JA ) and ethylene ( ET ) defence signalling pathways was investigated to better understand the nature of this plant–microbe interaction. The in planta bioassays revealed a key role for the ETR1 receptor as the etr1‐1 mutant plants exhibited statistically less F usarium wilt symptoms compared to the other mutant and Col‐0 plants. Quantitative polymerase chain reaction ( qPCR ) analysis associated the decrease in symptom severity shown in etr1‐1 plants with reduced vascular growth of the pathogen, suggesting the activation of defence mechanisms in etr1‐1 plants against F . oxysporum . Furthermore, the early activation and increased accumulation of the SA ‐responsive PR1 , PR2 and PR5 genes in the etr1‐1 plants, in contrast to the Col‐0 plants that showed higher transcript levels of the JA / ET ‐responsive PR3 , PR4 and PDF1.2 genes after F . oxysporum inoculation, can lead to speculation that F . oxysporum hijacks ETR1 ‐mediated ethylene signalling to promote disease development in plants.