Genomic Insights Into Biocontrol and Plant Growth‐Promoting Mechanisms of Paenibacillus maysiensis LHJ6 Against Root Rot in Panax notoginseng

Panax notoginseng (P. notoginseng), a medicinal herb rich in bioactive saponins derived from its roots, exhibits diverse pharmacological activities relevant to cardiovascular diseases. Root rot, a devastating soil-borne disease, threatens the sustainability of P. notoginseng production. Biological control is a green and effective approach for disease control. Herein, we successfully isolated a biocontrol strain, Paenibacillus maysiensis (P. maysiensis) LHJ6, from the rhizosphere of healthy P. notoginseng. Pot experiments demonstrated that LHJ6 reduced root rot incidence by 80.0% and the disease index by 75.0%, with significant efficacy observed under field conditions. Whole-genome sequencing revealed multifaceted mechanisms underlying biological control and plant growth promotion. Genomic analysis revealed a single circular chromosome spanning 6.13 Mb, with 5,886 protein-coding genes. LHJ6 exerted its potent biocontrol activity against plant pathogens through multiple mechanisms, including rhizosphere colonisation, production of diverse antifungal metabolites, degradation of pathogenic fungal cell walls, siderophore production, nitrogen fixation, and potential induction of systemic resistance in host. These findings offer fundamental insights into the biocontrol mechanisms of P. maysiensis strain LHJ6, providing a foundation for developing sustainable agricultural applications in P. notoginseng cultivation.