Can the DSE Fungus Exserohilum rostratum Mitigate the Effect of Salinity on the Grass Chloris gayana?

Author: mycolabadmin
8/15/2025
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Summary

Researchers tested whether a fungus called Exserohilum rostratum could help a forage grass called Rhodes grass survive in salty soil. The fungus did tolerate salt and helped the grass maintain better nutrient balance under salt stress, but it couldn’t fully protect the grass from severe salinity. The benefits were most noticeable under moderate salt conditions, suggesting the fungus works best in less extreme environments.

Background

Dark septate endophytes (DSEs) are fungal symbionts commonly found in saline environments and have been studied for their potential to enhance plant salt tolerance. Chloris gayana (Rhodes grass) is a subtropical forage grass that has been introduced to salt-affected soils in the Flooding Pampas of Argentina. This study investigated whether the DSE fungus Exserohilum rostratum, isolated from C. gayana, could mitigate salinity stress on its host plant.

Objective

To evaluate the salt tolerance of Exserohilum rostratum and its ability to enhance Chloris gayana’s tolerance to increasing salinity levels through symbiotic interaction. The study assessed fungal growth, root colonization, plant biomass production, and chemical composition under three salinity levels.

Results

The fungus tolerated salinity and maintained root colonization (approximately 30%) without salinity inhibition. Fungal inoculation enhanced shoot biomass only under non-saline conditions in the first experiment but showed no significant effect in the second experiment. Under moderate salinity, inoculated plants showed increased root biomass compared to non-inoculated plants. Inoculated plants maintained higher K/Na and Ca/Na ratios across all salinity levels despite overall biomass reduction.

Conclusion

While E. rostratum demonstrated salinity tolerance and expressed functional traits including enzyme production and phosphate solubilization, its ability to enhance plant performance under salt stress was context-dependent and limited to specific conditions. The fungus promoted selective nutrient uptake but could not fully compensate for severe salinity stress effects on plant growth.

Published in:Plants (Basel),
Study Type:Experimental Study,
Source: 10.3390/plants14162537; PMID: 40872160