Abstract
Fruit colour, a quality attribute of great importance for melon, is related to the accumulation of carotenoids, which are essential for human health as they are vitamin A precursors and vary in content, giving rise to different pulp colours. Thus, this study aimed to investigate the colour characteristics anPd expression of candidate genes involved in carotenoid metabolism in climacteric ‘Gaucho’ and non-climacteric ‘Eldorado’ melon fruit during development and ripening. The change in rind and pulp coloration in ‘Gaucho’ occurred suddenly in the last stages of maturation, whereas this transition occurred continuously and gradually in ‘Eldorado’. The expression of phytoene synthase 3 was higher in ‘Gaucho’ than in 'Eldorado' and remained constant throughout the developmental period. In addition, two carotene isomerase genes and one carotene hydroxylase gene showed higher expression in ‘Gaucho’, indicating the greater significance of these genes in the formation of aromatic compounds and other derivatives of carotenoid metabolism since they alone do not explain the formation of different colours in the cultivar Gaucho. This study contributes to our understanding of the carotenoid pathway in the Cucurbitaceae family and provides a foundation for future research on the manipulation of nutritional and commercial quality.