IPyA glucosylation mediates light and temperature signaling to regulate auxin-dependent hypocotyl elongation in <i>Arabidopsis</i>
Chen Lü, Xu‐Xu Huang, Shu-Man Zhao, Dong-Wang Xiao, Langtao Xiao, Jianhua Tong, Wen-Shuai Wang, Yanjie Li, Zhaojun Ding, Bingkai Hou
Abstract
Significance Auxin plays a crucial role in the life cycle of plants. In plant cells, auxin concentration must be closely controlled for optimal auxin responses. However, the underlying mechanism governing auxin homeostasis remains largely unknown. In this study, UDP-glycosyltransferase (UGT76F1) has been identified as involved in auxin homeostasis by glucosylation of the major auxin precursor (IPyA) to form IPyA glucose conjugates (IPyA-Glc). This glucosylation process is negatively regulated by the transcription factor PIF4 and plays a vital role in light- and temperature-dependent hypocotyl growth. This study suggests that IPyA-Glc formation is a key event in the control of auxin biosynthesis, thereby revealing a mechanism of auxin homeostasis that adapts to the plant environment through IPyA glucosylation.