Chrysophanol is involved in the biofertilization and biocontrol activities of Trichoderma

- Chrysophanol stimulates plant growth.
- Chrysophanol stimulates CO2 fixation and phloem loading.
- Chrysophanol elicits host defence responses.
- Chrysophanol functions in Trichoderma as an elicitor.

The effect of chrysophanol, a secondary metabolite of Trichoderma harzianum, on the growth and disease resistance of cabbage against Botrytis cinerea was investigated. Chrysophanol assisted cabbage growth and promoted resistance against B. cinerea. Proteins related to photosynthesis were expressed in T. harzianum- and chrysophanol-treated cabbages. The transcription levels of photosynthesis- and sucrose transport-related genes increased in chrysophanol-treated cabbages. The transcription levels of chitinase increased in T. harzianum-treated cabbages and those of ascorbate peroxidase in T. harzianum- and chrysophanol-treated cabbages. Chrysophanol is involved in stimulating plant growth and photosynthesis and in eliciting host defense responses during the colonization of T. harzianum.