Metabolomics reveals how ethylene-auxin interaction delays tomato ripening maintaining fruit nutritional and sensorial quality

The antagonistic roles of ethylene and auxin are well established, although the exact role of auxin in ripening regulation remains unclear. A metabolomic approach can be a strategy to understand the role of this phytohormone in improving tomato quality. This study used metabolomic approaches to investigate how the interaction between ethylene and auxin affects tomato fruit nutritional and sensorial quality, with a particular emphasis on aroma metabolites. Tomato (Solanum lycopersicum cv. Micro-Tom) fruits were randomly grouped according to treatment with ethylene (ETHY), auxin (IAA), or both (ETHY + IAA) phytohormones. Fruits without treatment were grouped in CTRL. Ethylene and auxin treatments affected carbohydrates (fructose, sucrose, and glucose), organic acids (citric and malic acids), and amino acids (valine, asparagine, and GABA), with the main volatile organic compounds precursors positively impacting ETHY + IAA aroma compounds. In conclusion, the comparison of metabolome profiles suggests that auxin regulation may overlap the ethylene regulatory system. Furthermore, tomato fruits treated with both phytohormones maintained metabolic profiles similar to those of untreated fruits in delayed ripening conditions, besides the improved tomato aroma. Employing metabolomic approaches to investigate how the interaction between ethylene and auxin affects tomato fruit quality, this study provides new insights into how both phytohormones may regulate tomato primary metabolism. Furthermore, it suggests how this combined treatment could enhance tomato quality in delayed ripening conditions. image