Beyond nutrient concentration: A call for uptake in mycorrhizal research under drought

Abstract Arbuscular mycorrhizal fungi (AMF) play a critical role in enhancing plant growth and drought resistance by facilitating nutrient (particularly nitrogen [N] and phosphorus [P]) acquisition. However, a widespread methodological issue persists in mycorrhizal research under drought as most studies assess the contributions of AMF solely through plant nutrient concentration, which may lead to erroneous conclusions due to biomass dilution effects. Here, we show that relying on nutrient concentration in plant tissues severely underestimates the contributions of AMF on plant N (47.2%) and P (66.3%) acquisition, and this underestimation is amplified during drought (N: 55.6%; P: 90.9%). Moreover, it may even result in erroneous conclusions in some cases. We strongly advocate that future mycorrhizal research should simultaneously report nutrient uptake, concentration and biomass metrics to more accurately quantify AMF contributions to plant nutrient acquisition. Read the free Plain Language Summary for this article on the Journal blog.