Jasmonates negatively interfere with fruit development and ripening in peach (Prunus persica L. Batsch).

Jasmonates (JAs) are signal molecules which elicit stress responses through JAs-responsive genes; they are also involved in developmental processes, including fruit growth and ripening. In the present study, methyl jasmonate (MJ) and n-propyl dyhydrojasmonate (PDJ) were applied to peach trees at the S1, S3 and S4 phases. In all cases, both chemicals inhibited climacteric ethylene production and delayed flesh softening leading to a ripening delay. A trascriptome profiling of JA-treated versus control fruit indicated that MJ down-regulates genes positively involved in fruit ripening (for instance 1-aminocyclopropane-1-carboxylic acid oxidase and polygalacturonase) while up-regulates several defence-related genes, including allene oxide synthase (AOS) which is involved in JA biosynthesis, and cell wall-related genes.