The increasingly powerful term mycorrhiza warrants attention

As climate pressures intensify, human pressure on the environment increases, and the search for sustainable agricultural solutions becomes more urgent, interest in plant symbioses has surged across disciplines, policy makers, and consumers. Among the many plant–microbial symbioses, arbuscular mycorrhizal (AM) association represents one of the most ancient and ecologically significant relationships between plants and fungi, with major implications for plant nutrition, soil health, and ecosystem resilience (Martin & van der Heijden, 2024). Indeed, AM fungi colonize the roots of c. 72% of terrestrial plants and are known to support uptake of phosphorus and other minerals, reduce plant stress, and improve soil structure (van der Heijden et al., 2015; Genre et al., 2020).

At the same time, advances in molecular biology and genetics are shedding new light on the regulatory circuits underpinning these interactions. In a recent landmark study published in Nature, Cook et al. (2025) demonstrate that a single point mutation in a gene encoding a nuclear-localized cyclic nucleotide-gated channel (CNGC15) can induce spontaneous calcium oscillations, enhancing the establishment of both nitrogen-fixing and mycorrhizal symbioses, even under nutrient-rich conditions that typically suppress them. This discovery represents a leap forward in our ability to manipulate plant–microbe interactions and paves the way for integrating endosymbioses more robustly into future cropping systems.

This momentum in scientific progress and broad public interest also highlights a critical conceptual issue: the increasingly frequent misuse of the term mycorrhiza, which threatens to undermine clear scientific communication at a time when interdisciplinary understanding is more important than ever.

The term mycorrhiza was introduced by Albert Bernhard Frank in 1885 to describe the mutualistic association between plant roots and fungi. Derived from the Greek mykes (fungus) and rhiza (root), it refers specifically to the symbiotic relationship, not to the fungus itself. Yet, a troubling trend has emerged, in which the term is increasingly used to denote the fungal partner – particularly in statements, such as ‘plants interact with arbuscular mycorrhiza’, a formulation that depicts mycorrhiza as the symbiont rather than the symbiosis.

While seemingly minor, this misusage signals a broader conceptual slippage. Such phrasing risks reinforcing a plant-centric bias that oversimplifies the intricate, bidirectional nature of the symbiosis. By reducing the fungal partner to an anonymous, passive player or, worse, conflating it with the entire symbiotic phenomenon, we miss the opportunity to appreciate the specificity and agency of these microorganisms. Analogously, one would not say that legumes interact with ‘nitrogen-fixing nodules’ but with rhizobia – the bacterial symbionts hosted inside root nodules. Indeed, this type of conflation appears to be far less frequent in the literature, suggesting an imbalance in conceptual precision between neighboring research fields.

The growing public and scientific fascination with plant–fungal symbioses is a double-edged sword. On the one hand, it reflects long-overdue recognition of the crucial roles mycorrhizal fungi play in ecosystem functioning, plant health, and even climate resilience (Brundrett & Tedersoo, 2018; Trivedi et al., 2020; Zhang et al., 2025). On the other hand, this surge of interest, particularly among those new to the field, has facilitated the dissemination of simplified narratives that often sacrifice terminological accuracy for accessibility (Robinson et al., 2024).

This trend is not confined to popular science. Misuse of ‘mycorrhiza’ is increasingly visible in the peer-reviewed literature, including high-impact journals, as well as in product marketing. Commercial inoculants, for example, are frequently labeled as containing a percentage of ‘mycorrhiza’, a phrase that misrepresents the biological material being sold – usually spores or other propagules of AM fungi. This not only confuses consumers and farmers but also risks diminishing public trust in science-based products.

Precision in language is not a matter of pedantry. It shapes how we conceptualize biological systems, how we communicate with the public, and ultimately how we design and implement solutions. Inaccurate terminology may distort experimental interpretation, obscure causal relationships, and misguide both agricultural practice and policy. The critical role of accurate scientific information in building a reliable body of knowledge and avoiding misunderstandings is vividly illustrated in Fig. 1, where prompting an OpenAI language model to generate an image of a mycorrhizal interaction resulted in a whimsical and scientifically inaccurate depiction, reflecting AI's current limited understanding of specialized scientific topics.

As mycorrhizal symbiosis research enters a transformative era – fueled by discoveries, such as the CNGC15 mutant study (Cook et al., 2025) – the importance of clear and consistent terminology cannot be overstated. In a field so reliant on interdisciplinarity, including ecologists, geneticists, agronomists, and even policymakers and farmers, clear communication across conceptual divides hinges on the use of precise language.

We therefore advocate for a renewed commitment to accurate usage of the term mycorrhiza, both in scientific writing and in applied contexts. In teaching, writing, and public engagement, it is essential to emphasize that mycorrhiza is not a substance or an organism but a dynamic and reciprocal interaction.

The discovery by Cook and colleagues is especially compelling because it challenges a long-standing assumption: that mutualistic symbioses are suppressed under nutrient-replete conditions. That symbiotic signaling can now be decoupled from such environmental constraints opens new avenues for breeding and biotechnological approaches aimed at enhancing root symbioses even in fertilized agricultural soils.

At this intersection of innovation and terminology, we face a moment of opportunity. As our capacity to harness symbioses expands, so must our commitment to articulating them precisely. Language matters, especially when it frames the very systems we aim to understand and transform.

None declared.

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