Effect of Ripening Temperature and Fluorescent Light Irradiation on Carotenoid Biosynthesis of Tomato 「Shonan Pomoron Red」

Abstract

In this study, we determined the appropriate ripening conditions for early harvesting, and analyzed the phenotype and gene expression of 「Shonan Pomoron Red」 a tomato bred in Kanagawa Agricultural Technology Center. Tomatoes harvested at the breaker stage ripened at various temperatures, and the results showed that accumulation of lycopene was promoted by 20-25°C ripening treatments. Gene expression levels of phytoene synthase (PSY) and carotenoid isomerase (CRTISO) were also higher at similar temperatures. On the other hand, at 5 or 35°C, the level of lycopene accumulations was low. Fluorescent lamp irradiation also increased accumulations of lycopene and β-carotene, and accelerated fruit coloration. Moreover the expression of carotenoid biosynthesis-related genes was also increased indicating that fluorescent lamp irradiation activates the carotenoid biosynthesis pathway. These results indicate that the appropriate ripening temperature and light irradiation of 「Shonan Pomoron Red」 can affect lycopene and β-carotene accumulations and expressions of carotenoid biosynthesis-related genes at phenotypic and gene expression levels.