Development of transgenic tomato lines with enhanced lycopene content using RNAi approach

Abstract:

Most people eat tomatoes for flavour, but it’s the lycopene that fights oxidative damage in their cells. This research used RNA interference (RNAi) to silence the lycopene β-cyclase (LCY-B) gene in tomato (Solanum lycopersicum cv. Micro-Tom), redirecting carotenoid flux toward lycopene accumulation. Three independent RNAi lines (RNAi-1, -2, -3) and the wild type were grown in controlled-environment chambers at Fukuoka and Sapporo during 2021–2023. HPLC analysis showed that the best line, RNAi-1, accumulated 14.8 mg lycopene 100 g^-1 FW—139% above the wild type (6.2 mg 100 g^-1). LCY-B transcript was suppressed by 78–89% in RNAi lines. β-carotene fell proportionally (41–58% reduction), confirming that the silencing redirected substrate away from the cyclisation branch. Fruit size, yield per plant, and Brix values were not significantly affected. These lines provide proof-of-concept for RNAi-mediated nutritional improvement of tomato and could serve as pre-breeding material for high-lycopene cultivar development.