Study on Effect and Mechanism of β-Aminobutyric Acid on Mango Anthracnose Caused by Colletotrichum gloeosporioides

Anthracnose is one of the most serious postharvest diseases that can manifest in mango. The mechanism and inhibitory effects of <i>β</i>-aminobutyric acid (BABA) on anthracnose in harvested mango fruit were investigated. The "Guifei" fruits were pretreated with different concentrations of 25, 50, 75, and 100 mmol/L BABA, with 0 mmol/L BABA as the control, and inoculated with <i>Colletotrichum gloeosporioides</i>. The results showed that 50 mmol/L BABA treatment significantly reduced the incidence of anthracnose and inhibited the growth of lesions in mango. It significantly increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), while reducing the O₂^- production rate and H₂O₂ content. In addition, the DPPH radical scavenging capacity was enhanced, the content of disease-resistance-related compounds, including total phenols and total flavonoids, increased, and the expression levels of defense-related genes such as PAL, GLU, CHI, and PR1 were upregulated, elevating the activity of phenylalanine ammonia-lyase (PAL) and pathogenesis-related proteins such as chitinase (CHI) and <i>β</i>-1,3-glucanase (GLU). In conclusion, BABA treatment significantly enhances mango fruit resistance to anthracnose via synergistically activating the antioxidant defense system, promoting the accumulation of disease-resistant compounds, and regulating defense-related gene expression. These findings provide a theoretical foundation for developing eco-friendly strategies to control postharvest diseases in mango.