1. An LRH-RSL4 feedback regulatory loop controls the determinate growth of root hairs in Arabidopsis.
- Author
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Cui, Meng Qi, Xu, Chen, Wang, Tao, Zhao, Li Hua, Wang, Yu Xuan, Li, Gui Xin, Yan, Jing Ying, Xu, Ji Ming, Liu, Rong, Wang, Zhi Ye, Harberd, Nicholas P., Zheng, Shao Jian, and Ding, Zhong Jie
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ROOT hairs (Botany) , *HAIR growth , *ROOT growth , *HAIR cells , *ARABIDOPSIS , *PLANT-water relationships - Abstract
Root hairs are tubular-shaped outgrowths of epidermal cells essential for plants acquiring water and nutrients from the soil. Despite their importance, the growth of root hairs is finite. How this determinate growth is precisely regulated remains largely unknown. Here we identify LONG ROOT HAIR (LRH), a GYF domain-containing protein, as a unique repressor of root hair growth. We show that LRH inhibits the association of eukaryotic translation initiation factor 4Es (eIF4Es) with the mRNA of ROOT HAIR DEFECTIVE6-LIKE4 (RSL4) that encodes the master regulator of root hair growth, repressing RSL4 translation and thus root hair elongation. RSL4 in turn directly transactivates LRH expression to maintain a proper LRH gradient in the trichoblasts. Our findings reveal a previously uncharacterized LRH-RSL4 feedback regulatory loop that limits root hair growth, shedding new light on the mechanism underlying the determinate growth of root hairs. [Display omitted] • Long Root Hair (LRH) is required for the determinate growth of root hairs • LRH inhibits root hair elongation via repression of RSL4 protein accumulation • LRH interacts with eIF4Es to repress RSL4 translation in root hair cells • RSL4 directly transactivates LRH expression to form a feedback regulatory loop How the determinate growth of root hairs is precisely controlled remains largely unknown. Cui et al. identify a novel factor, LRH, that represses RSL4-dependent root hair elongation at the translational level. RSL4 in turn directly transactivates LRH expression to form a feedback regulatory loop, fine-tuning the determinate growth of root hairs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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