Herbicide treatments alter carotenoid profiles for ¹⁴C tracer production from tomato (Solanum lycopersicum cv. VFNT cherry) cell cultures

Progress in learning about underlying carotenoid bioactivity mechanisms has been limited because of the lack of commercially available radiolabeled lycopene (LYC), phytoene (PE), and phytofluene (PF). Tomato (Solanum lycopersicum cv. VFNT cherry) cell cultures have been treated to produce [ ¹⁴C]-PE and PF but with relatively low yields. To increase carotenoid production, two bleaching herbicides were administered during the culture incubation, 2-(4-chlorophenyl-thio)triethylamine and norflurazon, separately or in combination to produce varying ratios of PE, PF, and LYC. Treatment with both herbicides resulted in optimal production of all three carotenoids. Subsequently, cultures were incubated in [ ¹⁴C]-sucrose-containing media to produce labeled LYC, PE, and PF. Adding [ ¹⁴C]-sucrose on day 1 of the 14 day culture incubation cycle to norflurazon-treated cultures led to a small increase in labeling efficiency compared to adding it on day 7. Improved culture conditions efficiently provided sufficient ¹⁴C- carotenoids for future cell culture and animal metabolic tracking studies.