Exploring arbuscular mycorrhizal fungi effects on grapevine growth under nutrients deficiency

Abstract

Among the key factors defining the terroir, soil nutrient dynamics play a pivotal role in shaping grapevine growth and yield. Micronutrients such as boron (B), zinc (Zn), copper (Cu) or molybdenum (Mo) have essential roles in grapevine development processes, including pollen germination, they also act as enzyme cofactors, and enhance nitrogen assimilation (Liu et al., 2022). Soil micronutrient availability depends on soil pH, organic matter, and biological interactions. Among vineyard microorganisms, arbuscular mycorrhizal fungi (AMF) are particularly significant, as their symbiotic associations with grapevines substantially enhance nutrient and water uptake, and overall vine resilience (Velaz et al., 2025). Most studies related with AMF and nutrient uptake have focused on nitrogen (N) and phosphorus (P); however, their influence on micronutrient, such as magnesium (Mg), Zn, B and Mo, acquisition remains unclear (Trouvelot et al., 2015).

In this context, we aimed to investigate whether AMF influence the uptake of micronutrients (Zn, Mo, and B) under conditions of low micronutrient availability. To this end, we designed a 2×2 factorial experiment in a greenhouse using fruit-bearing cuttings of Vitis vinifera L. cv. ‘Tempranillo’. Half of the plants were inoculated with the commercial mycorrhizal inoculum Aegis Sym Micorrizas Irriga. The other half (non-inoculated plants) received a filtered inoculum to restore other accompanying microorganisms. Plants were irrigated weekly with complete Hoagland solution, and nutrient-deficient solutions (after removing Zn, B, and Mo, respectively). Irrigation continued until berries reached maturity (20°Bx). We then assessed the influence of the AMF inoculum on vine vegetative growth by measuring root and shoot biomass, root/shoot biomass ratio, water content and nutrient content in different tissues.

Two-way ANOVA revealed that AMF inoculation had a significant positive effect on both shoot and root biomass under Zn-deficient conditions. For the other parameters, no significant differences were observed. However, nutrient-deficient conditions (B and Mo) significantly affected average shoot length and root water content in non-inoculated plants compared to non-deficient conditions. Specifically, B and Mo deficiency increased the average shoot length, while Mo deficiency also increased the root water content. Quantitative analysis through qPCR suggested that some of these differences were explained by differential expression of micronutrient transporters in roots.

To sum up, according to our results, AMF inoculation improves grapevine nutrient status and growth under nutrient deficiency conditions associated to climate change effects. However, it is noteworthy that these results are depended on the deficient micronutrient, and that they were conducted under greenhouse conditions.

References

Liu, L, An, M, Meng, Li, X, Jie, Han, Z, Li, S, Xuan, & Li, B. (2022). Molybdenum-induced effects on nitrogen absorption and utilization under different nitrogen sources in Vitis vinifera. Journal of Plant Interactions, 17, 756–765). https://doi.org/10.1080/17429145.2022.2089752

Trouvelot, S, Bonneau, L, Redecker, D, van Tuinen, D, Adrian, M, & Wipf, D. (2015). Arbuscular mycorrhiza symbiosis in viticulture: a review. In Agronomy for Sustainable Development, 35(4), 1449–1467. https://doi.org/10.1007/s13593-015-0329-7

Velaz, M, Santesteban, LG, & Torres, N. (2025). Mycorrhizae and grapevines: the known unknowns of their interaction for wine growers’ challenges, Journal of Experimental Botany, 76(11), 3001–3015. https://doi.org/10.1093/jxb/eraf081