原文链接：

Multiple phytohormones promote root hair elongation by regulating a similar set of GENEs in the root epidermis in Arabidopsis

原文摘要：

Multiple phytohormones, including auxin, ethylene, ａnd cytokinin, play vital roles in regulating cell development in the root epidermis. However, their interactions in specific root hair cell developmental stages are largely unexplored. To bridge this gap, we employed geneticand pharmacological approaches as well as transcriptional analysis inorder to dissect their distinct ａnd overlapping roles in root hairinitiation ａnd elongation in Arabidopsis thaliana. Our results show that among auxin, ethylene, ａnd cytokinin, only ethylene induces ectopicroot hair cells in wild-type plants, implying a special role of ethylene inthe hair initiation stage. In the subsequent elongation stage, however,auxin, ethylene, ａnd cytokinin enhance root hair tip growth equally. Our data also suggest that the effect of cytokinin is independent fromauxin ａnd ethylene in this process. Exogenous cytokinin restores roothair elongation when the auxin ａnd ethylene signal is defective, whereas auxin ａnd ethylene also sustain elongation in the absence ofthe cytokinin signal. Notably, transcriptional analyses demonstrated thatauxin, ethylene, ａnd cytokinin regulate a similar set of root hair-specific genes. Together these analyses provide important clues regarding the mechanism of hormonal interactions ａnd regulation inthe formation of single-cell structures.