摘要: Carotenoids, one of the most abundant groups of lipid-soluble antioxidants in higher plants, play important roles in light harvesting and photoprotection. Although nearly all genes of carotenoid biosynthetic pathway (CBP)have been reported in Arabidopsis thaliana, little is known about expression and regulation of CBP genes in tetraploid plants such as Nicotiana tabacum. To unravel the expression and regulation of CBP genes in tetraploid plants, a systematic transcriptional analysis of CBP genes was performed in Nicotiana species at fast growing period. Results showed that carotenoid contents and expression of NtPSY, NtPDS, NtZDS, NtCRTISO, Ntβt-LCY, Ntβ-OHase, NtZE, NtVDE in the leaves of modern tobacco cultivars were higher than those in the ancestral species. In addition, the expression levels of NtPSY, NtPDS, NtZDS, NtCRTISO, Ntβ-LCY, NtZE, NtVDE were higher in leaves than in other organs while Ntβ-OHase displayed the highest level in petal and pistil. Carotenoid contents were highly correlative to CBP gene transcript levels. These results suggest that CBP has genetically evolved to accumulate more carotenoids in leaves of modern tobacco cultivars.