Halotolerant Endophytic Fungi: Diversity, Host Plants, and Mechanisms in Plant Salt–Alkali Stress Alleviation

Author: mycolabadmin
9/18/2025
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Summary

Salty and alkaline soil is destroying farmland worldwide, but special fungi living inside plants can help crops survive these harsh conditions. These fungi work like a team with plants, producing protective substances and helping plants manage salt and reduce damage from stress. Scientists reviewed 150 studies and found these fungi boost crop yields by 15-40%, offering a natural way to farm on degraded land without more chemicals.

Background

Saline-alkali soil degradation affects over 1.381 billion hectares globally, reducing crop yields by 30% and threatening agricultural sustainability. Halotolerant endophytic fungi (HEFs) have emerged as promising biological agents to mitigate salt-alkali stress in plants. These fungi colonize plant tissues asymptomatically while enhancing host stress tolerance through multiple physiological mechanisms.

Objective

This comprehensive review analyzes 150 scientific publications to systematically examine the diversity, host range, isolation techniques, and molecular mechanisms by which halotolerant endophytic fungi enhance plant tolerance to salt-alkali stress. The study aims to establish a framework for understanding fungal-plant symbiosis and identify pathways for agricultural application.

Results

HEFs isolated from over 30 host plant species across 42 genera and 30 families demonstrate host coverage 2.8 times higher than ordinary endophytic fungi. Key mechanisms include osmolyte production (glycerol, trehalose, proline), active Na+ exclusion via SOS1 activation, antioxidant enzyme enhancement (SOD, CAT, APX), and phytohormone modulation. Field trials show 15-40% yield increases, though colonization efficiency decreases from 70-90% in lab to 30-50% in field conditions.

Conclusion

Halotolerant endophytic fungi represent a critical biological resource for mitigating salt-alkali stress through multifaceted mechanisms involving ion homeostasis, antioxidant capacity, and bioactive metabolite production. While laboratory and field validations demonstrate promising results, significant challenges remain including host specificity, colonization efficiency under field conditions, and interactions with soil microbiota. Future research should focus on ecological adaptability, synthetic biology modifications, and encapsulated delivery systems for practical agricultural implementation.

Published in:Plants (Basel),
Study Type:Review,
Source: PMC12473926, PMID: 41012059