School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore.
State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Cell Rep. 2023 Jan 31;42(1):111913. doi: 10.1016/j.celrep.2022.111913. Epub 2022 Dec 29.
Lateral root (LR) initiation is controlled by the pericycle and the neighboring endodermis in Arabidopsis. Here, we demonstrate that UBIQUITIN-SPECIFIC PROTEASE14/DA3 regulates LR initiation by modulating auxin signaling in the pericycle and endodermis. DA3 negatively affects the mRNA and protein levels of AUXIN RESPONSE FACTOR7 (ARF7) and ARF19 in the pericycle and endodermis but positively regulates the protein stability of SHORT HYPOCOTYL 2 (SHY2/IAA3), an auxin signaling repressor, in the endodermis. We show that DA3 interacts with ARF7 and ARF19, inhibiting their binding to the locus of LATERAL ORGAN BOUNDARY DOMAIN16 (LBD16) to repress its expression in the pericycle. SHY2 also interacts with ARF7 and ARF19 in the endodermis and enhances the DA3 repressive effect on ARF7 and ARF19, thus modulating LBD16 expression in the pericycle. Overall, our findings show that DA3 acts with SHY2, ARF7, and ARF19 to coordinate auxin signaling in the pericycle and endodermis to control LR initiation in Arabidopsis.
侧根 (LR) 的起始受拟南芥中中皮层和相邻内皮层的控制。在这里，我们证明泛素特异性蛋白酶 14/DA3 通过调节中皮层和内皮层中的生长素信号来调节 LR 的起始。DA3 负调控中皮层和内皮层中 AUXIN RESPONSE FACTOR7 (ARF7) 和 ARF19 的 mRNA 和蛋白水平，但正调控内皮层中生长素信号抑制剂 SHORT HYPOCOTYL 2 (SHY2/IAA3) 的蛋白稳定性。我们表明，DA3 与 ARF7 和 ARF19 相互作用，抑制它们与 LATERAL ORGAN BOUNDARY DOMAIN16 (LBD16) 的位点结合，从而抑制其在中皮层中的表达。SHY2 也在内皮层中与 ARF7 和 ARF19 相互作用，并增强 DA3 对 ARF7 和 ARF19 的抑制作用，从而调节中皮层中 LBD16 的表达。总的来说，我们的研究结果表明，DA3 与 SHY2、ARF7 和 ARF19 一起作用，协调中皮层和内皮层中的生长素信号，以控制拟南芥中 LR 的起始。
