Ethylene signalling affects susceptibility of tomatoes to S almonella

Summary Fresh fruits and vegetables are increasingly recognized as important reservoirs of human pathogens, and therefore, significant attention has been directed recently to understanding mechanisms of the interactions between plants and enterics, like S almonella . A screen of tomato cultivars for their susceptibility to S almonella revealed significant differences in the ability of this human pathogen to multiply within fruits; expression of the S almonella genes ( cysB ,   agfB ,   fadH ) involved in the interactions with tomatoes depended on the tomato genotype and maturity stage. Proliferation of S almonella was strongly reduced in the tomato mutants with defects in ethylene synthesis, perception and signal transduction. While mutation in the ripening‐related ethylene receptor Nr resulted only in a modest reduction in S almonella numbers within tomatoes, strong inhibition of the S almonella proliferation was observed in rin and nor tomato mutants. RIN and NOR are regulators of ethylene synthesis and ripening. A commercial tomato variety heterozygous for rin was less susceptible to S almonella under the greenhouse conditions but not when tested in the field over three production seasons.