Molecular mechanisms of plant hormones and sugars regulates strawberry fruit development and ripening

The strawberry consists of two main parts: the dry achenes (the true fruit) and an enlarged receptacle (the fleshy part). These parts exhibit high metabolic synchrony during the development and ripening stages. Due to the low rates of ethylene production and respiration during ripening, strawberries are currently classified as non-climacteric fruits. However, studies suggest that ethylene, along with its interactions with other plant growth regulators like abscisic acid and auxin influences the ripening process in strawberries. Auxins are crucial for the initial development of fruits, promoting cell expansion and modulating non-climacteric ripening. Recent research indicates that cytokinins and gibberellins might play a role in enhancing fruit development and ripening by promoting cell expansion. Additionally, the literature suggests that increased sugar concentration, accompanied by cell wall degradation and changes in pulp osmotic pressure, is linked to hormonal crosstalk between growth promoters, abscisic acid and ethylene. Although traditionally classified as non-climacteric, recent evidence may suggest that strawberries operate under a model similar to 'suppressed climacteric'. In this system, ethylene does not act as the primary trigger, but rather as an essential modulator of late ripening. Thus, strawberry ripening reflects a sophisticated hormonal interaction essential to the strawberry ripening cascade.