Biological control efficacy of Bacillus licheniformis HG03 against soft rot disease of postharvest peach

Abstract

This study aimed to investigate the biocontrol ability of Bacillus licheniformis HG03 against Rhizopus stolonifer causing agent of peach fruit rot and explore its mechanism. The biocontrol strain B. licheniformis HG03 was applied on inhibition of the pathogen Rhizopus stolonifer, which is expected to improve the preservation of peach fruit. The results revealed that the peach treated with B. licheniformis HG03 were significantly more resistant to postharvest soft rot when stored at 20 °C and high humidity. Comparison to the control, treatment with HG03 improved the activity of related enzymes and balanced the metabolism of reactive oxygen species. Such treatment reduced the accumulation of lipid peroxidation products and enhanced free radical scavenging ability of peaches. Furthermore, the transcriptome analysis revealed that the HG03 treatment activated MAPK signaling pathway, induced the expression of antioxidant activity-related genes and different WRKY transcription factors in plant pathogen interaction metabolic pathway. Hence, the results revealed that HG03 treatment is an effective biological control method to improve peach fruit disease resistance and prolong the storage time of peaches.