LncRNA4504 involved in methyl jasmonate-induced resistance to Botrytis cinerea in postharvest tomato fruit

•MeJA induced lncRNA4504 expression and tomato fruit resistance to B. cinerea.•The silence of lncRNA4504 aggravated the development of tomato fruit disease.•LncRNA4504 silence counteracted the effects of MeJA on fruit disease resistance.•LncRNA4504 positively regulated MeJA-induced tomato fruit resistance to B.cinerea. Our previous study screened a long non-coding RNA, lncRNA4504, whose expression was largely increased responding to methyl jasmonate (MeJA) treatment in tomato fruit. However, the roles of lncRNA4504 in MeJA-induced fruit resistance remains unclear. Here, lncRNA4504 was silenced using virus-induced gene silencing (VIGS) to investigate its function in MeJA-mediated defense responses to Botrytis cinerea (B. cinerea) in tomato fruit. The data showed that tomato fruit treated with MeJA (0.05 mmol L−1, 12 h) exhibited lower disease symptoms, and higher total phenols and flavonoids contents and defensive enzymes activities, as well as higher transcripts of pathogenesis-related genes (SlPR1 and SlPR-STH2) than control fruit during storage. In addition, MeJA treatment also promoted the transcripts of genes related to jasmonic acid (JA) biosynthesis (SlLOXD, SlAOS and SlAOC) and its signal transduction (SlMYC2 and SlCOI1) along with increased endogenous JA content compared to control. However, lncRNA4504 silence almost counteracted the effects of MeJA on the above indexes, leading to higher disease incidence and lesion diameter in (lncRNA4504-silenced + MeJA) group than those in MeJA group. These findings indicated that lncRNA4504 may play vital roles in the tomato disease resistance induced by MeJA, possibly by promoting the accumulation of total phenols and total flavonoids, enhancing defense enzyme activities, and upregulating the expression of JA signal pathway genes.