Evaluation of Carotenoids Accumulation and Biosynthesis in Two Genotypes of Pomelo (Citrus maxima) during Early Fruit Development

Abstract

Pomelo is rich in bioactive compounds (carotenoids, phenolics and essential oil) in the early stage of fruit development, but it is often wasted in the cultivation and management process. To gain an insight into the carotenoid metabolism pathway in pomelo, the carotenoid profiles and the expression patterns of carotenogenic genes were investigated in two genotypes of pomelo during early fruit development. The results showed that a higher carotenoid content was observed in honey pomelo as compared with golden pomelo, which may be related to different gene regulation mechanisms. Lutein, α-carotene, and β-carotene were the main carotenoids in pomelo young fruit, and lutein was the highest one. The accumulation of carotenoids during fruit early development in honey pomelo is related to the transcriptional regulation of ZISO and LUT5. In golden pomelo, the rate-limiting gene for carotenoids is PDS and ZDS. In addition, the expression of seven genes except CRTISO in honey pomelo was higher than that in golden pomelo. The results are helpful to further clarify the regulatory mechanism of carotenoid accumulation during early fruit development and provide a direction for the high-value utilization of young fruits in pomelo.

Volatiles Accumulation during Young Pomelo (Citrus maxima (Burm.) Merr.) Fruits Development

“…Two genotypes of young pomelos Golden Pomelo (GP) and Honey Pomelo (HP) studied in the present work were grown in Meizhou Honey Pomelo National Industrial Park (Meizhou, China; 24°19′ N, 116°07′ E) with systematical management. The growing condition could be referred to the published work [ 11 ]. Each variety of young pomelos were collected at four developmental stages (Stage 1 to 4), which were divided by pomelos diameters around 2, 4, 6, and 8 cm (corresponding days after pollen: 30, 40, 47 and 54), and were from three pomelo trees with similar growth patterns.…”

“…J inyou , GP) and Honey Pomelo ( Citrus grandis cv. Miyou , HP), are widely planted and predominantly traded [ 11 ]. Similarity in outlooks, the two varieties are discrepant in flavors.…”

Citrus maxima (Brum.) Merr. (Rutaceae): Bioactive Chemical Constituents and Pharmacological Activities

“…Carotenoids are important dietary constituents and also improve the immune response in the plant [ 71 ]. The isolated carotenoids from the fruit include β -carotene, phytoene, lutein, zeaxanthin, α -carotene, β -cryptoxanthin, and lycopene [ 45 – 48 , 72 ].…”

α‐Carotene: a valuable carotenoid in biological and medical research

“…), and bright-colored flowers (chrysanthemum, marigold, lonicera japonica, etc.). [13][14][15][16][17][18]…”