Molecular and Biochemical Impact of Selenium on the Acceleration of Ripening and Quality Changes in ‘Camarosa’ Strawberry Fruits

Selenium is an essential micronutrient for humans, underscoring its importance in enhancing the nutritional and physiological attributes of agricultural and horticultural crops through exogenous application. At low doses, selenium improves growth and development, and increases crop yield and quality, particularly under stress conditions. It is believed that abscisic acid and sucrose work together to regulate strawberry (Fragaria × ananassa Duch.) fruit ripening. This study aimed to provide comprehensive biochemical and molecular insights into the selenium mediated effects on ripening and quality changes in ‘Camarosa’ strawberry fruits. Selenium treatment increased chlorophyll levels in leaves, suggesting a positive impact on overall plant health. Foliar application of 1 mM selenium significantly accelerated ripening. Treated fruits exhibited higher levels of total soluble solids, along with a decrease in titratable acidity. About lipid peroxidation indices, foliar application of 1 mM selenium decreases hydrogen peroxide and malondialdehyde. Consistently, flavonoids, phenolic compounds, anthocyanins, ascorbic acid, and antioxidant capacity, as well as the activity of the enzymes SOD, CAT, APX and PAL, were increased by selenium treatment. Interestingly, the ABA content in strawberry fruits also increased with selenium treatment. The selenium treatment upregulated genes involved in abscisic acid biosynthesis, phenolic compound biosynthesis, and anthocyanin production, namely, FaNCED1, FaG2BD, FaCHS, FaPAL, and FaSUT1. This study highlights the potential of selenium as a biostimulant and quality-enhancing agent in strawberries, improving fruit biochemical composition and ripening dynamics while contributing to better nutritional value and market appeal.