| Summary: | The K<sup>+</sup> transporter KT/HAK/KUP (K<sup>+</sup> transporter/high-affinity K<sup>+</sup>/K<sup>+</sup> uptake) family has a critical effect on K<sup>+</sup> uptake and translocation in plants under different environmental conditions. However, the functional analysis of KT/HAK/KUP members in sweet potatoes is still limited. The present work reported the physiological activity of a new gene, <i>IbHAK11</i>, in the KT/HAK/KUP family in sweet potatoes. <i>IbHAK11</i> expression increased significantly in the low K<sup>+</sup>-tolerant line compared with the low K<sup>+</sup>-sensitive line following treatment with low K<sup>+</sup> concentrations. <i>IbHAK11</i> upregulation promoted root growth in <i>Arabidopsis</i> under low K<sup>+</sup> conditions. Under high saline stress, transgenic lines had superior growth and photosynthetic characteristics compared with the wild-type (WT). As for <i>IbHAK11</i>-overexpressing plants, activation of both the non-enzymatic and enzymatic reactive oxygen species (ROS) scavenging systems was observed. Therefore, <i>IbHAK11</i>-overexpressing plants had lower malondialdehyde (MDA) and ROS levels (including H<sub>2</sub>O<sub>2</sub> and O<sup>2−</sup>) compared with WT under salt-induced stress. We also found that under both low K<sup>+</sup> and high salinity conditions, overexpression of <i>IbHAK11</i> enhanced K<sup>+</sup> translocation from the root to the shoot and decreased Na<sup>+</sup> absorption in <i>Arabidopsis</i>. Consequently, IbHAK11 positively regulated K<sup>+</sup> deficiency and high salinity stresses by regulating K<sup>+</sup> translocation and Na<sup>+</sup> uptake, thus maintaining K<sup>+</sup>/Na<sup>+</sup> homeostasis in plants.
|
|---|