Quantitative Trait Loci Pyramiding Can Improve the Nutritional Potential of Tomato (Solanum lycopersicum) Fruits

Abstract

Solanum lycopersicum represents an important source of antioxidants and other bioactive compounds. Previously two Solanum pennellii introgression lines (IL 7-3 and IL 12-4) were identified as carrying quantitative trait loci (QTL) increasing fruit ascorbic acid and phenolics content. Novel tomato lines were obtained by pyramiding these selected QTLs in the genetic background of the cultivated line M82. Pyramided lines revealed significant increases of total phenolics, phenolic acids, ascorbic acid, and total antioxidant activity compared to parental lines IL 7-3 and IL 12-4 and the cultivated line M82. In addition, tomato extracts obtained from the pyramided lines had no cytotoxic effect on normal human cells while exhibiting a selective cytotoxic effect on aggressive cancer cells. Therefore, the present study demonstrates that it is possible to incorporate favorable wild-species QTLs in the cultivated genetic background to obtain genotypes with higher nutritional value.

Antioxidant bioactive compounds in tomato fruits at different ripening stages and their effects on normal and cancer cells

“…Hydrophilic and lipophilic fractions were obtained according to Rigano et al (2014). Briefly, 3 g of tomato frozen powder were extracted with 30 mL of 70% methanol into an ultrasonic bath for 60 min at 30°C.…”

“…Ascorbic acid (AsA) determination was carried out by a colorimetric method (Stevens, Buret, Garchery, Carretero, & Causse, 2006), with modifications previously reported by Rigano et al (2014). TCA 6% (300 µL) was added to 500 mg of frozen powder.…”

“…Total phenolic compounds were evaluated by using the Folin-Ciocalteu assay (Singleton & Rossi, 1965) with modifications reported by Rigano et al (2014). Briefly, 62.5 µL of FolinCiocalteu's phenol reagent and 250 µL of dd H2O were added to 62.5 µL of supernatant obtained from the above extractions.…”

“…The extract was passed through a 0.45 µm Millipore nylon filter (Bedford, MA, USA). Flavonoids and phenolic acids were separated and quantified by using a HPLC Spectra System SCM 1000 (Thermo Electron Corporation, San Jose, CA, USA) equipped with a Gemini column (3 µm C18, 110 A, 250 × 4.6 mm; Phenomenex, Torrance, CA, USA) and UVvisible detector according to the procedure reported by Rigano et al (2014). Chromatograms were recorded at 280 nm for gallic acid and chlorogenic acid, and at 365 nm for coumaric acid, ferulic acid, rutin and its derivative, quercetin and naringenin.…”

“…Hydrophilic tomato extracts, obtained as reported above, were concentrated in a rotary evaporator and the residue was dissolved in 5% dimethyl sulphoxide (DMSO) in PBS and then added to the cells (3 mg/mL final concentration) 24 hours after seeding for time course cytotoxicity assays. At the end of incubation, cell viability was assessed by MTT assay as described by Rigano et al (2014). For each cell line, a calibration curve was obtained by plating an increasing number of cells per well (0.5-7 × 10 3 ).…”