An LCI-like protein APC2 protects ginseng root from Fusarium solani infection

Abstract

Aims: We aimed to purify an antimicrobial protein from Bacillus amyloliquefaciens FS6 culture supernatant, verify its antimicrobial activity against Fusarium solani and evaluate its biocontrol potential for ginseng root rot. Methods and Results: The antimicrobial protein was purified from FS6 culture supernatant using ammonium sulphate precipitation, anion exchange and gel chromatography. Based on mass spectrometry results, the purified protein was identified as an antimicrobial protein of the LCI family and was designated APC2. The APC2 recombinant protein expressed in Escherichia coli (BL21) significantly inhibited F. solani and decreased the infection and spread of F. solani in ginseng root. An overexpressing APC2 strain FS6-APC2 was constructed and shown to have enhanced antimicrobial activity compared to the wild-type strain FS6. Conclusions: The APC2 protein shows strong antimicrobial activity against F. solani, reduces the incidence and severity of ginseng root rot caused by F. solani and exhibits a great biocontrol potential. Significance and Impact of the Study: This study reports the inhibitory activity of APC2 protein (LCI family) against F. solani and its protective efficacy on ginseng root rot. These findings provide a scientific basis for future research on the biocontrol mechanism, as well as the development and application of FS6.