Krittaya Supathaweewat and Preekamol Klanrit

pp. 517 - 527

Abstract

We report on the cloning of Psy1, Pds and Zds cDNAs encoding the enzymes responsible for lycopene biosynthesis,
namely phytoene synthase 1 (PSY1), phytoene desaturase (PDS) and  ζ-carotene desaturase (ZDS), respectively, from highlycopene tomato cultivar, Solanum lycopersicum KKU-T34003. DNA sequence analyses showed that the complete open
reading frames of Psy1, Pds and Zds cDNAs were 1,239, 1,752 and 1,767 base pairs in length and encoded proteins of 412,
583 and 588 amino acids, respectively. Phylogenetic and the conserved domain analyses suggest that PSY1, PDS and ZDS
from S. lycopersicum KKU-T34003 potentially have similar structures and biological functions to the corresponding proteins
from other plants. Gene expression studies showed that Psy1 was expressed only in the petal and the breaker fruit, whereas
the expressions of Pds and Zds were observed in the petal, the breaker fruit and the leaf. The highest expression level for all
genes was detected in the breaker-stage fruit, suggesting that carotenoid accumulation was developmentally regulated in
the chromoplast-containing tissues.