The Regulation Mechanisms of Carotenoid Biosynthesis in Apricot (Prunus armeniaca)

摘要

To elucidate the regulation mechanisms of carotenoid biosynthesis in apricot fruit (Prunus armeniaca), two colour-contrasted apricot varieties, 'Goldrich' (GO) and 'Moniqui' (MO), were analysed at biochemical and molecular levels. Fruits from GO are orange and mainly accumulate beta-carotene as well as uncoloured precursors of carotenoids, phytoene and phytofluene. MO fruits are ivory coloured and only accumulate phytoene and phytofluene. These results suggest regulations at transcriptional level ofcarotenogenic genes, and more particularly of some key genes encoding phytoene synthase (psy), phytoene desaturase (pds) or zeta -carotene desaturase (zds). The corresponding genes (cDNA) were isolated in both apricot varieties and their expression werequantified during apricot development and ripening. Results showed that expression of each gene increased during ripening process and that expression was higher in the ivory MO variety than in the orange GO. According to physiological, biochemical and molecular approaches, different suggestions on carotenoid regulation in apricots are presented and discussed.