Arbuscular mycorrhizal (AM) fungi play a positive role in plant water relations, and the AM symbiosis is often cited as beneficial for overcoming drought stress of host plants. Nevertheless, water uptake via mycorrhizal hyphal networks has been little addressed experimentally, especially so through isotope tracing. In a greenhouse study conducted in two-compartment rhizoboxes, Medicago truncatula was planted in the primary compartment (PC), either inoculated with Rhizophagus irregularis or left uninoculated. Plant roots were either allowed to enter the secondary compartment (SC) or were restricted to the PC by root-excluding mesh. Substrate moisture was manipulated in the PC such that the plants were grown either in high moisture (15% of gravimetric water content, GWC) or low moisture (8% GWC). Meanwhile, the SC was maintained at 15% GWC throughout and served as a water source accessible (or not) by roots and/or hyphae. Water in the SC was labeled with deuterium (D) to quantify water uptake by the plants from the SC. Significantly, increased D incorporation into plants indicated higher water uptake by mycorrhizal plants when roots had access to the D source, but this was mainly explained by generally larger mycorrhizal root systems in proximity to the D source. On the other hand, AM fungal hyphae with access to the D source increased D incorporation into plants more than twofold compared to non-mycorrhizal plants. Despite this strong effect, water transport via AM fungal hyphae was low compared to the transpiration demand of the plants.

Department of Mycorrhizal Symbioses Institute of Botany of the Czech Academy of Sciences Průhonice Czech Republic

Laboratory of Fungal Biology Institute of Microbiology of the Czech Academy of Sciences Prague Czech Republic

Leibniz Institute of Vegetable and Ornamental Crops e 5 Grossbeeren Germany

Citace poskytuje Crossref.org

Common mycorrhizal networks improve survival and mediate facilitative plant interactions among Andropogon gerardii seedlings under drought stress

Soil compaction reversed the effect of arbuscular mycorrhizal fungi on soil hydraulic properties

Elucidating the Mechanisms Underlying Enhanced Drought Tolerance in Plants Mediated by Arbuscular Mycorrhizal Fungi

Arbuscular Mycorrhiza Mediates Efficient Recycling From Soil to Plants of Nitrogen Bound in Chitin