Metabolomic analyses during chayote (Sechium edule var. virens levis) seed germination under the influence of growth regulators

The fruit of chayote ( Sechium edule ) has a recalcitrant seed, as a consequence, viviparism (seed germination inside the fruit) occurs in the first 13 days after harvest. However, at the moment no phytohormone–dependent metabolic changes have been described that would allow us to understand the hormonal relationship during germination. Untargeted and targeted metabolomic analyses were performed on chayote seed treated with plant growth regulators, evaluated in fruits at 7 and 10 days after harvest. Exogenous application of 2–chloroethylphosphonic acid (ethylene releaser) and gibberellic acid 3 accelerated germination and viviparism, while auxins and abscisic acid delayed them. Metabolic pathways and possible key metabolites regulating germination were identified, including ethylene, gibberellins, auxins and abscisic acid. This study suggests a likely hormone interaction model during chayote seed germination. • Gibberellins and ethylene promoted early seed germination in chayote fruit. • Auxins and abscisic acid delay the basal opening of the fruit. • Hormonal relationships that regulate viviparism are analyzed by metabolomic tools.