Novel proto-panaxatriol ginsenocide biocontrol agents for ginseng root rot and replant disease

Overview

Ginseng root rot and replant disease, caused by the soil-inhabiting fungal pathogen Cylindrocarpon destructans, are persistent problems that reduce yields and limit the replanting of ginseng in the same fields. This proposal introduces a novel biocontrol strategy based on proto-panaxatriol (PPT) ginsenocides, which have been shown to inhibit C. destructans hyphal growth by 30–60%. Unlike most soil fungi, C. destructans is stimulated by the proto-panaxadiol (PPD) ginsenocides that make up roughly 90% of the total ginsenocides found in ginseng roots and root secretions. By introducing targeted PPT-type compounds into the soil environment, the project aims to suppress this pathogen while supporting sustainable ginseng production.

The approach also adds value to a common agricultural waste stream. Ginseng fibre, a by-product generated on commercial ginseng farms, can be enzymatically transformed to convert Rb1 ginsenocides into the desired G-XVII and F2 congeners. This creates a circular, farm-integrated route to producing the biocontrol agent.

Technical specifications

Key features:

• Biocontrol agents derived from PPT-type ginsenocides (G-XVII and F2 congeners)
• 30–60% reduction in C. destructans hyphal growth observed with PPT ginsenocides
• Enzymatic transformation of Rb1 ginsenocides in ginseng fibre waste into the target PPT compounds
• LC-MS/MS-based analytical methods for compound isolation and characterization
• Soil microbiology expertise applied to agricultural product development

Research hypothesis: Growth of C. destructans will be inhibited by PPT ginsenocides, which can be adopted as novel biocontrol agents in high-value ginseng production.

Validation procedure: Published reports from Chinese and Korean laboratories (since 2018) show that PPT ginsenocides reduce C. destructans hyphal growth. However, those studies used fungal strains indigenous to Asia. The proposed work will test efficacy on strains found in Canadian farm soils and isolate G-XVII and F2 ginsenocides for product formulation.

Technology readiness level

This technology is at an early stage of development (TRL 2–3). Published laboratory evidence from international collaborators demonstrates proof-of-concept inhibition of C. destructans by PPT ginsenocides, but validation on North American fungal strains has not yet been performed. The next planned steps are: (1) confirm inhibition of Canadian strains of C. destructans by PPT ginsenocides (approximately 6 months), and (2) isolate G-XVII and F2 ginsenocides through enzymatic transformation of ginseng fibre waste for product formulation (approximately 6 months). The principal investigator has experience with LC-MS/MS, soil microbiology, and development of products for agricultural soils, supporting progression toward field-ready formulations.