Induced Defense in Avocado Fruits Mediated by Secondary Metabolites Produced by <i>Bacillus atrophaeus</i> B5

Abstract

Biocontrol agents are an environmentally friendly alternative to chemical pesticides against phytopathogens. The effectiveness of metabolites produced by Bacillus atrophaeus B5 for controlling anthracnose produced by Colletotrichum gloeosporioides in harvested fruit and the possible action mechanisms have been studied. Avocado fruit treated with metabolites reduced 54% of anthracnose incidence and nearly 70% of the lesion than untreated fruit. The treatment enhanced the activities of peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase. Additionally, the transcription of PAL and EIN3-like genes related to defense were increased. These results suggest that metabolites produced by B. atrophaeus B5 enhance disease resistance against C. gloeosporioides in avocado fruit. In the fruit, the induced resistance is related to the priming of defense responses. Metabolites in the cell-free supernatant could also be a potential biological preservative for avocado protection.

Keywords

• bacterial metabolites
• gene expression
• resistance induction
• <i>priming</i>