The CBL1/9-CIPK23-AKT1 complex is essential for low potassium response in cassava.

Cassava is a food crop and an important energy crop worldwide. However, its yield and quality are easily affected by low K+ stress, and the molecular mechanism of potassium channel is unknown in cassava. Herein, we revealed that calcineurin B-like 1/9 (MeCBL1/9)-CBL-interacting protein kinase 23 (MeCIPK23)-K+ TRANSPORTER1 (MeAKT1) complex plays an important role in low potassium response in cassava. Firstly, this study verified the in vivo role of MeAKT1 in K+ uptake in yeast. Secondly, we found that MeCBL1, MeCBL9, MeCIPK23 and MeAKT1 are involved in the absorption of K+ in cassava, and MeCBL1/9-CIPK23 complex is essential for MeAKT1-mediated K+ uptake. Moreover, MeCBL1/9-MeCIPK23-MeAKT1 showed different expression in different cassava varieties contrasting in the resistance to low K+ stress. Taken together, this study provides new insights into further improvement of K+ uptake in cassava.