Cloning and expression of CitPDS1, a gene encoding phytoene desaturase in citrus

A cDNA clone encoding phytoene desaturase (PDS) was isolated from citrus (C itrus unshiu Marc,), The transcript of the isolated PDS (CitPDS1) was not d etected by conventional RNA gel-blot analysis; instead, it was detected by a sensitive reverse transcription-PCR (RT-PCR), The CitPDS1 transcript in t he juice sacs/ segment epidermis (edible part) was at a low level in the yo ung fruit, and it increased toward maturation like citrus phytoene synthase (CitPSY1), In the peel, in contrast to CitPSY1, the transcript of which wa s induced toward maturation, the level of the CitPDS1 transcript remained c onstant after an increase in July, indicating non-coordinate regulation of CitPDS1 and CitPSY1 in the peel.