Plant–fungus symbiosis — naming the association with roots A very common mutualistic, symbiotic relationship between a fungus and the roots of a plant is called what?

Introduction / Context:
Plants and fungi often form mutualisms that improve nutrient and water acquisition. The best-known root–fungus partnership has a specific name that appears across ecology, botany, and agriculture curricula.

Given Data / Assumptions:

• Symbiosis is between plant roots and a fungus.
• Mutual benefits include enhanced nutrient uptake and carbon supply to the fungus.
• We must identify the standard term for this association.

Concept / Approach:

Mycorrhizae are associations in which fungal hyphae colonize root cortex tissues or soil around roots (ectomycorrhizae and endomycorrhizae). The plant gains improved uptake of phosphorus, nitrogen, and micronutrients; the fungus receives photosynthate. This boosts plant fitness, particularly in nutrient-poor soils.

Step-by-Step Solution:

Verification / Alternative check:

Ecology and plant physiology texts define mycorrhizae as the primary plant–fungus mutualism at roots, distinct from lichen.

Why Other Options Are Wrong:

Lichen involves a photosynthetic partner and fungi, not plant roots. “Ascomycete” and “Basidiomycete” are fungal phyla, not relationships. “Rhizobium” is a nitrogen-fixing bacterium associated with legumes, not a fungus.

Common Pitfalls:

Confusing mycorrhiza with lichen or with bacterial nodulation. Always match the partners in the definition.

Final Answer:

Mycorrhiza (mycorrhizal association)