Background <p>Potassium (K) is one of the most important elements that has different functions in plants. Although K⁺ ions are found in large quantities in soil, their availability is limited due to strong adsorption to soil minerals. In this study, the effect of symbiosis of arbuscular mycorrhiza fungi (AMF), <i>Rhizophagus irregularis</i> and <i>Funneliformis mosseae</i> with bean roots on the absorption of K⁺, phosphorus and sodium as well as the activity of potassium transporters was investigated.</p> Results <p>The results revealed that the symbiosis with both AMFs increased the absorption of K⁺ and phosphorus in the roots and transfer to the shoots. Also, under salinity stress, AMFs have been able to increase the K⁺/Na⁺ ratio and reduce the harmful effects of salinity. Besides, morphological traits such as plant height, stem diameter, number of side branches, and length of fruit increased under AM symbiosis conditions. In the comparison between AMFs, <i>R. irregularis</i> showed a greater ability in K⁺ availability than <i>F. mosseae</i>. Nineteen members of the KUP family (PvKUP) were identified and they were different from each other in terms of gene structure and physicochemical properties. Based on the phylogenetic tree, the members of PvKUP family were placed in five groups and the several duplications was identified between them. Gene expression pattern analysis showed that <i>PvKUPs</i> have both tissue-specific expression and general expression. <i>PvKUP16</i> was expressed only in root cells inoculated with <i>R. irregularis</i>, while <i>PvKUP18</i> showed increased expression in both root tissues and aerial organs.</p> Conclusions <p>Overall, the results of this research determined that AMFs are effective in increasing potassium absorption in beans, although more studies are needed to better understand the mechanisms related to this interaction.</p>