Transcriptome atlas provides novel insights into ABA-mediated modulation of strawberry fruit ripening and quality

Abstract The plant hormone abscisic acid (ABA) regulates fruit growth, development, and ripening, playing a pivotal role in fruit quality during non-climacteric ripening. As a typical non-climacteric fruit, strawberries rely on ABA to promote ripening. However, the optimal concentration for ABA treatment and the mechanisms through which ABA signaling influences gene targets that determine key quality attributes, such as sugar-acid balance and coloration, remain poorly understood. This study examined the effects of exogenous ABA and its inhibitor nordihydroguaiaretic acid (NDGA) on white-stage 'Benihoppe' strawberries. Phenotypic observations and quality measurements were conducted. Results revealed that 0.2 mM ABA treatment most significantly increased soluble sugar content, anthocyanin levels, and the sugar-acid ratio while decreasing fruit firmness and organic acid concentrations. In contrast, NDGA treatment produced opposite effects. RNA-seq analysis further identified differentially expressed genes primarily involved in flavonoid biosynthesis and fructose-mannitol metabolism, suggesting alterations in carbon metabolism within the fruit. These findings elucidate the role of ABA signaling in shaping strawberry quality during fruit development and highlight key genes as potential targets, providing a theoretical basis for advancing strawberry breeding and farming practices.