All plants host microbes, referred to as symbionts, that may live inside the plant or on its surface (mostly roots). Certain microbial symbionts improve the nutrient uptake of their host plants and help the plant to defend itself against pathogens. These actions are known as biofertilization and biocontrol. Much of the current research on plant symbionts focuses on pathogens. Therefore, we started investigating microbes beneficial for plants. More specifically, we isolated symbiotic fungi with biofertilization ability from field-grown cranberry plants and characterized them by microbiological and greenhouse experiments as well as by genomics and transcriptomics methods. We sequenced the genome of EC4 sequenced the RNA – RNA-Seq of EC4 when grown with cranberry plant roots.

The first paper we published in this subject area is on the isolation and taxonomic classification of bacteria and fungi living inside cranberries (Salhi et al., 2022). In our most recent research article entitled “Nuclear Genome Sequence and Gene Expression of an Intracellular Fungal Endophyte Stimulating the Growth of Cranberry Plants,” we show that one of the fungal endophytes called Endophytic Champignon 4 (EC4) grows inside and outside of cranberry plant roots and, in greenhouse tests, stimulates the growth of cranberry plantlets roots and shoots by utilizing potassium and tri-calcium phosphates sources. Its genome sequence reveals a large number of genes involved in nitrogen, phosphate and potassium nutrition and plant growth hormone production (Thimmappa et al., 2023).

Field trials with EC4 are underway in Quebec, Canada, in collaboration with Atoka Inc., Pampev Inc., Gillivert Inc., and Transport Gas-ton Nadeau Inc. Knowledge gained in our study has the potential to deploy fungi as biofertilizing agents in cranberry farming, contributing to sustainable agriculture. There is increasing interest among consumers and farmers alike to find alternatives to agrochemicals that have a negative impact on the environment.

Interestingly, the fungus EC4 also controls the growth of many plant pathogens, including cranberry plant and fruit rot pathogens. Stay tuned for a report on EC4’s biocontrol potential.

References

Salhi, L.N., Bustamante Villalobos, P., Forget, L., Burger, G., Lang, B.F., 2022. Endosymbionts in cranberry: Diversity, effect on plant growth, and pathogen biocontrol. PLANTS PEOPLE PLANET 4, 511–522. https://doi.org/10.1002/ppp3.10290

Thimmappa, B.C., Salhi, L.N., Forget, L., Sarrasin, M., Bustamante Villalobos, P., Lang, B.F., Burger, G., 2023. Nuclear Genome Sequence and Gene Expression of an Intracellular Fungal Endophyte Stimulating the Growth of Cranberry Plants. J. Fungi 9, 126. https://doi.org/10.3390/jof9010126