NO 3 − , PO 4 3 − and SO 4 2 − deprivation reduced LKT1 ‐mediated low‐affinity K + uptake and SKOR ‐mediated K + translocation in tomato and Arabidopsis plants

Regulation of essential macronutrients acquisition by plants in response to their availability is a key process for plant adaptation to changing environments. Here we show in tomato and Arabidopsis plants that when they are subjected to NO 3 − , PO 4 3 − and SO 4 2 − deprivation, low‐affinity K + uptake and K + translocation to the shoot are reduced. In parallel, these nutritional deficiencies produce reductions in the messenger levels of the genes encoding the main systems for low‐affinity K + uptake and K + translocation, i.e. AKT1 and SKOR in Arabidopsis and LKT1 and the tomato homolog of SKOR , SlSKOR in tomato, respectively. The results suggest that the shortage of one nutrient produces a general downregulation of the acquisition of other nutrients. In the case of K + nutrient, one of the mechanisms for such a response resides in the transcriptional repression of the genes encoding the systems for K + uptake and translocation.