Ectomycorrhizal fungi (EMF) can enhance drought resistance of host plants by increasing nutrient and water absorption. Calcium (Ca) plays a central role in drought stress adaptation, yet it remains unclear how EMF influence Ca uptake of plants under drought stress. We carried out a pot experiment in which Quercus acutissima seedlings were inoculated with or without the ectomycorrhizal (EM) fungus Xerocomus chrysenteron under control and water stress soil moisture conditions in order to investigate how soil Ca availability and plant Ca uptake are modulated by EMF and how this may contribute to drought resistance of the seedlings. We found that soil water-extractable Ca was significantly reduced by drought in non-ectomycorrhizal treatment, while EM treatment significantly increased soil Ca availability and Ca uptake of Quercus acutissima seedlings under drought conditions. Furthermore, seedling water use efficiency (WUE) was positively correlated with soil Ca availability and plant Ca content. Calcium uptake promotion seems to be involved in the mechanisms of drought tolerance enhancement by EMF.

外生菌根真菌（EMF）可通过增加养分和水分吸收来增强寄主植物的抗旱性。钙（Ca）在干旱胁迫适应中起着核心作用，但仍不清楚EMF如何影响干旱胁迫下植物对钙的吸收。我们进行了盆栽实验，其中接种或不接种外生菌根真菌（EM）的Xerocomus chrysenteron的拟南芥（Quercus acutissima）幼苗在控制和水分胁迫下的土壤湿度条件下，以研究EMF如何调节土壤Ca的有效性和植物对Ca的吸收，以及这如何有助于幼苗的抗旱性。我们发现，在非根除菌根处理中，干旱显着降低了土壤水可提取的钙，而在干旱条件下，EM处理显着提高了拟南芥幼苗的土壤钙利用率和钙吸收。此外，幼苗水分利用效率（WUE）与土壤钙有效性和植物钙含量呈正相关。钙的吸收促进似乎与EMF增强耐旱性的机制有关。