The miR166d/ Signaling Module Is a Critical Mediator of Wheat ( L.) Tolerance to K Deficiency.

It is well established that potassium (K) is an essential nutrient for wheat ( L.) growth and development. Several microRNAs (miRNAs), including miR166, are reportedly vital roles related to plant growth and stress responses. In this study, a K starvation-responsive miRNA (miR166d) was identified, which showed increased expression in the roots of wheat seedlings exposed to low-K stress. The overexpression of miR166d considerably increased the tolerance of transgenic Arabidopsis plants to K deprivation treatment. Furthermore, disrupting miR166d expression via virus-induced gene silencing (VIGS) adversely affected wheat adaptation to low-K stress. Additionally, miR166d directly targeted the calcium-dependent protein kinase 7-D gene () in wheat. The gene expression was decreased in wheat seedling roots following K starvation treatment. Silencing in wheat increased K uptake under K starvation. Moreover, we observed that the miR166d/ module could affect wheat tolerance to K starvation stress by regulating and expression. Taken together, our results indicate that miR166d is vital for K uptake and K starvation tolerance of wheat via regulation of .