A fungal endophyte strategy for mitigating the effect of salt and drought stress on plant growth

Fungal endophytes grow symbiotically inside plants, where some strains promote plant growth and survival under particular abiotic stresses. We colonized tomato plants with systemic (also called class 2) fungal endophytes isolated from plants naturally growing in salinized soil. We studied the effect of these strains on plant tolerance to NaCl and drought. Endophyte-colonized plants exposed to NaCl or drought had higher root and shoot biomass, better water-use efficiency, and higher photosynthetic efficiency than non-colonized plants. Endophyte-colonized plants also had lower reactive oxygen species content, implying a mechanism for stress tolerance. Our findings indicate that systemic fungal endophytes isolated from pioneer plants on salinized soil have the potential to confer tolerance to agriculturally and horticulturally important plants grown in arid environments.