Abstract: To reveal the function of ζ-carotene desaturase(ZDS) in Nicotiana tabacum(N.tabacum),NtZDS gene was homologously cloned from N.tabacum and its phylogenetic analysis was conducted.Fluorescence quantitative PCR technology was used to analyze the temporal and spatial expression patterns of NtZDS and tobacco rattle virus induced gene silencing(VIGS) system was employed to inhibit the expression of ZDS in Nicotiana benthamiana.The expression levels of upstream and downstream genes were further analyzed by fluorescence quantitative PCR,and the changes of pigment contents in tobacco plants were determined.The results showed that there existed at least two homologous copies of NtZDS gene in N.tabacum with the similarity of more than 90% in coding sequence to ZDS genes in tomato and potato.The expression level of NtZDS was the highest in leaves and flowers at flowering stage.Comparing with the control,the leaves of tobacco plants presented severe bleaching phenotype after NtZDS silencing,it provided a good candidate for reporter gene for VIGS system;meanwhile the expression levels of upstream and downstream genes and pigment contents(carotenoid and chlorophyll) significantly decreased,it implied that ZDS gene played an important role in the course of growth,development and carotenoid formation of N.tabacum.