A North American mycorrhizal fungus displays zinc tolerance intraspecific variation and protects pines from zinc toxicity.

A North American Suillus tomentosus fungus exhibits intraspecific variation in zinc tolerance that enhances pine seedling performance under zinc stress.

• Why it matters: Soil zinc pollution from human activities can harm plant metabolism and reproduction, but the role of fungal symbionts in zinc tolerance remains unclear, limiting effective mitigation strategies.
• What they did: Researchers used genomic, in vitro, bioassays, transcriptomics, and metabolomics approaches on S. tomentosus and P. contorta to investigate zinc tolerance, finding it is highly polygenic, constitutive, and linked to zinc exclusion and antioxidant responses.
• The result: Zin-tolerant S. tomentosus provides slightly more benefit to pine seedlings under zinc stress than zinc-sensitive strains, highlighting the importance of intraspecific variation for biodiversity and biotechnological applications.