The Accumulation of Lutein and β-Carotene and Transcript Profiling of Genes Related to Carotenoids Biosynthesis in Yellow Celery

Carotenoids are the general term of natural pigments. The formation of plant color is probably related to the components of carotenoids. As the yellow variety of celery, it is rich in the composition and content of carotenoids. However, the transcript profiling and roles of the genes related to carotenoids biosynthesis in yellow celery remain unclear. In this study, three yellow celery cultivars at different growth stages were used to analyze the content and composition of carotenoids and transcriptional changes of carotenoid biosynthesis-related genes. The lutein and beta-carotene were detected in yellow celery cultivar, while alpha-carotene and lycopene were not detected. The contents of lutein and beta-carotene were higher in leaf blades than in petioles. During the growth and development, the contents of lutein and beta-carotene gradually decreased in celery. Compared with the other two cultivars, the contents of lutein and beta-carotene were the highest in 'Huangtaiji' of 65 days after sowing (DAS) and 85 DAS and 'Liuhehuangxinqin' of 105 DAS, respectively. The expression levels of AgLCYB and AgPSY2 genes were significantly correlated with lutein and beta-carotene contents. This work provided a reference for the further study on carotenoid metabolisms in yellow celery and also made sense on the way of cultivating yellow celery with high carotenoids content.