Summary of some of the biological pathways involved in citrus fruit ripening. Red boxes indicate genes/proteins that were upregulated in MT compared with WT, brown boxes indicate genes/proteins that were upregulated during fruit ripening in WT, green boxes indicate genes/proteins that were downregulated in MT compared with WT, grey boxes indicate genes/proteins that were downregulated during fruit ripening in WT, and blue boxes represent genes/proteins that were shown to have mixed expression patterns (both up- and downregulation) in MT compared with WT. ACO, 1-aminocyclopropane-1-carboxylate oxidase; ETR, ethylene receptor; EBF, EIN3-binding F-box protein; ERF1, ethylene-responsive transcription factor; NCED, 9-cis-epoxycarotenoid dioxygenase; AAO, abscisic-aldehyde oxidase; PYR/PYL, abscisic acid receptor; PP2C, protein phosphatase 2C; SnRK2, serine/threonine-protein kinase SRK2; XET, xyloglucan endotransglycosylase; PG, polygalacturonase; PE, pectinesterase; GAUT, alpha-1,4-galacturonosyltransferase; SPS, sucrose-phosphate synthase; SS, sucrose synthase; CS, citrate synthase; and IDH, isocitrate dehydrogenase. (This figure is available in colour at JXB online.)