Jasmonates are phytohormones required for plant development and stress responses. During flower development, JA-insensitivity leads in the tomatomutant jai1 (jasmonate insensitive 1) to female sterility and reduced male fertility. This contrasts to the male sterile phenotype of the JA-insensitive A. thalianamutant coi1 (coronatine insensitive 1). Hormone profiles, untargeted transcriptome and metabolome analysis, as well as histological and physiological analysis were used for development of a model proposing how JA acts in tomato flower development. In stamen, JA regulates pollen nutrition and determines the function of the hormone ethylene regulating anther and pollen maturation afterwards. During ovule development, JA regulates defense, stability and supply of nutrition to the embryosac.