AUTHOR=Liu Taibo , Liu Qianyu , Yu Zhen , Wang Chunling , Mai Huafu , Liu Guolan , Li Ruijing , Pang Gang , Chen Dingwu , Liu Huili , Yang Jiangyi , Tao Li-Zhen 

TITLE=eIF4E1 Regulates Arabidopsis Embryo Development and Root Growth by Interacting With RopGEF7

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.938476

DOI=10.3389/fpls.2022.938476

ISSN=1664-462X

ABSTRACT=<p>Eukaryotic translation initiation factor 4E1 (<italic>eIF4E1</italic>) is required for the initiation of protein synthesis. The biological function of <italic>eIF4E1</italic> in plant–potyvirus interactions has been extensively studied. However, the role of <italic>eIF4E1</italic> in <italic>Arabidopsis</italic> development remains unclear. In this study, we show that <italic>eIF4E1</italic> is highly expressed in the embryo and root apical meristem. In addition, <italic>eIF4E1</italic> expression is induced by auxin. <italic>eIF4E1</italic> mutants show embryonic cell division defects and short primary roots, a result of reduced cell divisions. Furthermore, our results show that mutation in <italic>eIF4E1</italic> severely reduces the accumulation of PIN-FORMED (PIN) proteins and decreases auxin-responsive gene expression at the root tip. Yeast two-hybrid assays identified that eIF4E1 interacts with an RAC/ROP GTPase activator, RopGEF7, which has been previously reported to be involved in the maintenance of the root apical meristem. The interaction between eIF4E1 and RopGEF7 is confirmed by protein pull-down and bimolecular fluorescent complementation assays in plant cells. Taken together, our results demonstrated that eIF4E1 is important for auxin-regulated embryo development and root growth. The eIF4E1–RopGEF7 interaction suggests that eIF4E1 may act through ROP signaling to regulate auxin transport, thus regulating auxin-dependent patterning.</p>