Effect of farnesol on Trichoderma physiology and fungal-plant interaction

Authors: CARDOZA, ROSA - University Of Leon; McCormick, Susan; LINDO, LAURA - University Of Leon; MAYO-PRIETO, SARA - University Of Leon; GONZALEZ-CARON, D - University Of Leon; MARTINEZ-REYES, NATALIA - University Of Leon; CARRO-HUERGA, GUZMAN - University Of Leon; RODRÍGUEZ-GONZÁLEZ, ÁLVARO - University Of Leon; Proctor, Robert; CASQUERO, PEDRO - University Of Leon; GUTTIERREZ, SANTIAGO - University Of Leon

Submitted to: The Journal of Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2022
Publication Date: 11/30/2022
Citation: Cardoza, R.E., McCormick, S.P., Lindo, L., Mayo-Prieto, S., Gonzalez-Caron, D., Martinez-Reyes, N., Carro-Huerga, G., Rodríguez-González, Á., Proctor, R.H., Casquero, P.A., Guttierrez, S. 2022. Effect of farnesol on Trichoderma physiology and fungal-plant interaction. The Journal of Fungi. 8(12). Article 1266. https://doi.org/10.3390/jof8121266.
DOI: https://doi.org/10.3390/jof8121266

Interpretive Summary: The fungus Trichoderma has been used as a biocontrol agent that protects crops from harmful fungi like Botrytis and Fusarium that can cause disease. Trichoderma produces a chemical called farnesol that has many uses within the fungus. While we know that it helps to control cell growth, formation of filaments and biofilms, and production of some other fungal products, it wasn’t known if farnesol plays any role in the important antifungal and biocontrol activity of Trichoderma. In order to find out if and how farnesol helps Trichoderma fight plant disease, researchers at ARS and at the University of Leon, Spain, first identified the gene that produces farnesol. This allowed them to control how much farnesol was produced by the fungus and to determine if too much farnesol would be bad for the plant. They found that farnesol produced by Trichoderma triggers plant defense genes when a pathogen is attacking. This research will help to develop improved biocontrol agents to fight crop diseases.

Technical Abstract: Farnesol is an isoprenoid intermediate in the mevalonate (MVA) pathway and is produced by the dephosphorylation of farnesyl diphosphate. Farnesol plays a central role in cell growth and differentiation, controls production of ubiquinone and ergosterol, and participates in the regulation of filamentation and biofilm formation. Despite these important functions, studies of farnesol in filamentous fungi are limited, and information on its effects on antifungal and/or biocontrol activity is scarce. In the present article, we identified the Trichoderma harzianum gene dpp1, encoding a diacylglycerol pyrophosphatase that catalyzes production of farnesol from farnesol diphosphate. We analyzed the function of dpp1 to address the importance of farnesol in Trichoderma physiology and ecology. Overexpression of dpp1 in T. harzianum caused an expected increase in farnesol production as well as a marked change in squalene and ergosterol levels, but overexpression did not affect antifungal activity. In interaction with plants, a dpp1-overexpressing transformant acted as a sensitizing agent in that it up-regulated expression of plant defense salicylate-related genes in the presence of a fungal plant pathogen. In addition, toxicity of farnesol on Trichoderma and plants was examined. Finally, a phylogenetic study of dpp1 was performed to understand its evolutionary history as a primary metabolite gene. This article represents a step forward in the acquisition of knowledge on the role of farnesol in fungal physiology and in fungus-environment interactions.