β-Aminobutyric acid induces resistance of mango fruit to postharvest anthracnose caused by Colletotrichum gloeosporioides and enhances activity of fruit defense mechanisms

Abstract

The effect of β-aminobutyric acid (BABA) on control of anthracnose caused by Colletotrichum gloeosporioides in mango fruit and its possible mechanisms were investigated. The results show that BABA treatments effectively suppressed the expansion of lesion in mango fruit inoculated with C. gloeosporioides during storage at 25°C, with the greatest efficacy being obtained using 100mM BABA. However, BABA at 25–400mM did not exhibit direct antifungal activity against C. gloeosporioides in vitro. Furthermore, BABA treatment at 100mM enhanced the activities of β-1,3-glucanase (GLU), chitinase (CHT) and phenylalanine ammonia lyase (PAL). BABA treatment also contributed to the accumulation of hydrogen peroxide (H2O2), while decreasing the rate of superoxide radical (O2−) production. Concurrently, BABA increased the activity of superoxide dismutase (SOD), while inhibiting catalase (CAT) and ascorbate peroxidase (APX) activities. These results indicate that increased disease resistance of mango fruit after BABA treatment during storage might be attributed to an elicitation of defense response involving in the enhancement of defense-related enzyme activities and modulation of antioxidant system activities.