His-Ala-Phe-Lys peptide from Burkholderia arboris possesses antifungal activity

Abstract

Burkholderia arboris, which belongs to the Burkholderia cepacia complex, has been shown to possess antifungal activity against several plant fungal pathogens; however, the antifungal compounds are yet to be identified. Here, we identified the antifungal compounds produced by B. arboris using genetic and metabolomic approaches. We generated a Tn5 transposon mutation library of 3,000 B. arboris mutants and isolated three mutants with reduced antifungal activity against the plant fungal pathogen Fusarium oxysporum. Among the mutants, the M464 mutant exhibited the weakest antifungal activity. In the M464 genome, the transposon was inserted into the cobA gene, encoding uroporphyrin-III methyltransferase. Deletion of the cobA gene also resulted in reduced antifungal activity, indicating that the cobA gene contributed to the antifungal activity of B. arboris. Furthermore, a comparison of the differential metabolites between wild type B. arboris and the ∆cobA mutant showed a significantly decreased level of tetrapeptide His-Ala-Phe-Lys (Hafk) in the ∆cobA mutant. Therefore, a Hafk peptide with D-amino acid residues was synthesized and its antifungal activity was evaluated. Notably, the Hafk peptide displayed significant antifungal activity against F. oxysporum and Botrytis cinerea, two plant pathogens that cause destructive fungal diseases. Overall, a novel antifungal compound (Hafk) that can be used for the biocontrol of fungal diseases in plants was identified in B. arboris.

Comprehensive genomic analysis of Burkholderia arboris PN-1 reveals its biocontrol potential against Fusarium solani-induced root rot in Panax notoginseng

“…Previous studies have identi ed root rot as a key factor limiting the quality and yield of Sanqi, prompting focused research on the safe and effective prevention and control of Sanqi root rot. Within the B. cepacia complex, B. arboris has garnered attention for its ability to synthesize novel antifungal compounds, such as Hafk, exhibiting potent antifungal activity against diverse plant fungal pathogens (Zhu et al 2022). This study was designed to expand our understanding of the molecular biocontrol mechanisms employed by B. arboris PN-1.…”

“…Certain Burkholderia species, distinguished by unique biosynthetic gene clusters, act as promising biocontrol agents, producing antimicrobial metabolites (Petrova et al 2022). Among these, Burkholderia arboris, commonly found in the Burkholderia cepacia complex and frequently isolated from the rhizosphere, exhibits notable anti-fungal activity against various fungal plant pathogens (Zhu et al 2022). Extensive research underscores B. arboris as an effective biological control agent (Sandani et al 2019;Singh et al 2020;Zhang et al 2022).…”