Abstract: The β-carotene hydroxylase-1（HYD-1）, flavonone-3-hydroxylase（F3H） and flavonol synthase（FLS）are key enzymes in biosynthesis of flavonoid and carotenoid. The transcript levels of genes of these three key enzymes were investigated by semi-quantitative RT-PCR under drought (withholding watering for 0, 7, 10, 12, 14 days respectively) in drought tolerance genotype of diploid H145 and drought susceptive genotype of diploid H214. The results showed that the gene transcript of these three key enzymes was increased in leaves and roots of two genotypes under mild and moderate drought. In the genotype of H145, the transcript level of F3H gene in leaves increased faster than that in roots, and the duration of transcript of FLS & HYD-1 gene in leaves was longer than that in roots under drought stress. In genotype of H214, the duration of transcript of F3H gene in leaves was longer than that in the roots, the transcript level of FLS & HYD-1 gene in leaves increased slower than that in roots under drought stress. The results suggest that the genes of β-carotene hydroxylase-1, flavonone-3-hydroxylase and flavonol synthase were concerned with the drought tolerance in potato, and there might be different acting models of these genes under drought in different genotypes.

Key words: potato, Solanum tuberosum L., drought stress, flavonoid, carotenoid