As carotenoids were present in the ripe sarcotesta it was
possible to clone a partial cDNA coding for a phytoene
synthase (MgPHY), the expression of which was analyzed by
real-time PCR. Interestingly, the transcript amount was
highest in the orange samples, that is when pigment
accumulation occurs rapidly. Thereafter, in the red sarcotesta,
where most of the pigment had already accumulated, the
transcript amount showed a decrease (Fig. 4C, white
rectangles). Although in low amounts, transcripts of this
gene were always found in seeds deprived of their sarcotesta
(Fig. 4C, gray rectangles).