Fruit cuticle,which is composed of cutin and wax and biosynthesized during fruit development,plays important roles in the prevention of water loss and the resistance to pathogen infection during fruit development and postharvest storage.However,the key factors and mechanisms regarding the cuticle biosynthesis in citrus fruits are still unclear.Here,fruit cuticle ofNewhallnavel orange(Citrus sinensis Osbeck)was studied from the stages of fruit expansion to postharvest storage from the perspectives of morphology,transcription and metabolism.The results demonstrated cutin accumulation is synchronous with fruit expansion,while wax synthesis is synchronous with fruit maturation.Metabolic profile of fruits peel revealed that transition of metabolism of fruit peels occurred from 120 to 150 DAF and ABA was predicted to regulate citrus wax synthesis during the development of Newhall fruits.RNA-seq analysis of the peel from the above two stages manifested that the genes involved in photosynthesis were repressed,while the genes involved in wax,cutin and phenylpropanoids biosynthesis were significantly induced at later stages.Further real-time PCR revealed that MYB transcription factor GL1-like was predicted to regulate citrus fruits wax synthesis.These results are valuable for improving the fruit quality during development and storage.