Fig. 4.

Net K⁺ flux in the primary root meristem under different concentrations of K, with or without inhibitors (W: tobacco Wufeng No.2; Y: tobacco Yunyan 87; CC: cesium chloride, a potassium ion channel inhibitor; OV: orthovanadate, a plasma membrane H⁺-ATPase inhibitor). a The net K⁺ flux dynamics of the root meristem under normal K levels (5 mmol L^− 1). For all ion flux measurements, the sign convention is “influx positive.” (b) The mean net K⁺ flux of the root meristem under normal K levels (5 mmol L^− 1). Different lowercase letters denote significant differences (P < 0.05). (c) The net K⁺ flux dynamic of the root meristem under K starvation (0.5 mmol L^− 1). d The mean net K⁺ flux of the root meristem under K starvation (0.5 mmol L^− 1). Different lowercase letters denote significant differences (P < 0.05)