Low-level atmospheric ozone exposure induces protection against Botrytis cinerea with down-regulation of ethylene-, jasmonate- and pathogenesis-related genes in tomato fruit

► Tomato fruit pre-exposed to ozone had reduced fungal lesion development and enhanced protection. ► Tomatoes subjected to ozone enrichment retained fruit firmness. ► Wounded and/or inoculated (with Botrytis cinerea) tomato fruit had enhanced expression of both signal transduction and defence-related genes. ► Ozone treatment inhibited the expression of both signal transduction and defence-related genes.