K+ Nutrition Exchange in the Serendipita-Arabidopsis Symbiosis: Study of the Fungal K+ Transporters Involved

There is mounting evidence that the root-colonizing endosymbiotic fungus Serendipita indica improves plant growth. The beneficial effects have been observed when plants are growing in optimal conditions or under nutritionally deficient soils (e.g., phosphate poor soil) exposed to stressful environmental such as drought salinity. However, until now its role nutrition of other essential macronutrient, K + , has not fully clarified. Here, we study Arabidopsis thaliana plants, during growth limiting conditions. As a first step, studied high-affinity uptake and separately symbiosis. In search for putative fungal actors involved nutrition, also cloned functionally characterized transporters S. Si HAK1, TRK1, TRK2, TOK1, among which it shown HAK1 main transporter high affinity range concentrations. addition, gene expression these candidates could participate homeostasis carried out. results indicated that, contrary what happens with P seems improve neither nor reserves starvation. Instead, this restrictive condition favored colonization, suggesting obtains greatest benefit supply