Phytoene desaturase (PDS) has recently been identified as an important enzyme in carotenoid biosynthesis pathway. A cDNA clone encoding phytoene desaturase gene is isolated from stigma of saffron (Crocus sativus L.) using RT-PCR technique. Sequence analysis shows 83% similarity to Narcissus pseudonarcissus, 79% to Zea mays, 78% to Arabidopsis thaliana, 77% to Lycopersicon esculentum. A new full-length cDNA is obtained by 5'-RACE and 3' -RACE techniques. The cDNA is 2149bp long with an open reading frame of 1697bp, which encodes a polypeptide of 565 amino acids. Southern analysis shows that the PDS gene is a single copy in saffron. Northern blot analysis shows higher expression level of PDS gene in stigma and anther than in leaves and stem.
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