Exploring the influence of symbiosis between arbuscular mycorrhizal fungi and beans on potassium uptake and the activity of AKT and HKT genes.

In plants, potassium (K) serves multiple functions, despite being scarce due to strong soil adsorption. This study examined how the presence of arbuscular mycorrhiza fungi (AMF) like Rhizophagus irregularis and Funneliformis mosseae influenced the absorption and transport of K in bean roots through symbiotic interactions. In a symbiotic relationship, AMF had the potential to enhance potassium absorption and storage in various tissues of bean seedlings. Under symbiotic conditions, the concentration of potassium in stem tissues was observed to increase almost four times more than control conditions. The genome of beans was shown to contain a total of nineteen PvAKT genes and two PvHKT genes. Based on phylogeny analysis, PvAKT family members and their corresponding orthologs were categorized into four distinct groups. Subfamily 3 of the PvAKT phylogeny tree exhibited distinct variations from other subfamilies in terms of gene structure, conserved domains, and potential phosphorylation sites. The presence of cis-regulatory element related to ABA responsiveness in the upstream region led to the division of PvAKT and PvHKT genes into two specific groups. Gene expression analysis disclosed that PvAKT and PvHKT genes are induced by AMF and have tissue specific expression. PvAKT6 and PvAKT11 genes and both PvHKT genes showed differential expression in root and shoot tissues, while PvAKT3 gene increased expression in both root and shoot tissues. The results suggest that AMF had a significant impact on increasing the solubility of K and ultimately enhancing the function of K transporters.