Carotenoid isomerase （CRTISO）is a key enzyme that catalyzes the conversion of cis-lycopene to all- trans tycopene. In this study, we isolated and characterized the CRTISO gene from Lycium chinense （LcCRTISO） for the first time. The open reading flame of LcCRTISO was 1 815 bp encoding a protein of 604 amino acids with a molecular mass of 66.24 kDa. Amino acid sequence analysis revealed that the LcCRTISO had a high level of simi- larity to other CRTISO. Phylogenetic analysis displayed that LcCRTISO kept a closer relationship with the CRTISO of plants than with those of other species. Semi-quantitative PCR analysis indicated that LcCRTISO gene was expressed in all tissues tested with the highest expression in maturing fruits. The overexpression of LcCRTISO gene in transgenic tobacco resulted in an increase of total carotenoids in the leaves with [3-carotene and lutein being the predominants. The results obtained here clearly suggested that the LcCRTISO gene was a promising candidate for carotenoid production.
