Exogenous Gibberellic Acid (GA₃) Enhances Mango Fruit Quality by Regulating Resource-Related Metabolic Pathways.

Area of Science:

• Horticultural Science
• Plant Physiology
• Metabolomics

Background:

• Efficient resource allocation is crucial for mango fruit development and quality.
• Foliar application of plant growth regulators like gibberellic acid (GA3) can influence fruit characteristics.

Purpose of the Study:

• To quantify the effects of different GA3 concentrations on mango fruit physiochemical attributes during expansion and ripening.
• To investigate the metabolic changes associated with GA3 treatment using metabolomics and pathway analysis.

Main Methods:

• Foliar application of GA3 at 0, 50, 100, and 200 mg L-1 at different stages post-bloom.
• Measurement of fruit physiochemical traits, antioxidant enzyme activities, and malondialdehyde content.
• Metabolic profiling, principal component analysis (PCA), and KEGG pathway analysis.

Main Results:

• GA3 application increased fruit length, diameter, and weight. It also reduced starch and acidity while increasing soluble sugars during expansion.
• Antioxidant enzyme activities increased, and leaf MDA content decreased. Treated fruits showed reduced weight loss, improved firmness, color, and disease resistance, but lower vitamin C and TSS.
• PCA identified 100 mg L-1 GA3 (GA100) as optimal. Metabolomics revealed altered levels of 287 compounds, with upregulation of sweet/fruity aromas and downregulation of terpenoids.

Conclusions:

• Preharvest foliar GA3 application, especially at 100 mg L-1, enhances mango fruit growth and quality by modulating carbon, nitrogen, and energy metabolism.
• GA3 promotes efficient resource allocation towards fruit development and aroma, favoring ester production over complex terpenoid notes.