This website requires JavaScript.
DOI: 10.1101/2023.03.15.532802

NAC1 directs CEP1-CEP3 peptidase expression and decreases cell wall extensins linked to root hair growth in Arabidopsis

D. R.Rodriguez-Garcia E. Marzol Y. d. C. Rondon Guerrero ...+14 J. Estevez
摘要
Plant genomes encode a unique group of papain-type Cysteine EndoPeptidases (CysEPs) containing a KDEL endoplasmic reticulum (ER) retention signal (KDEL-CysEPs or CEPs). CEPs process the cell-wall scaffolding EXTENSIN proteins (EXTs), which regulate de novo cell wall formation and cell expansion. Since CEPs are able to cleave EXTs and EXT-related proteins, acting as cell wall-weakening agents, they may play a role in cell elongation. Arabidopsis thaliana genome encodes three CEPs (AtCPE1-AtCEP3). Here we report that the three Arabidopsis CEPs, AtCEP1-AtCEP, are highly expressed in root-hair cell files. Single mutants have no evident root-hair phenotype, but atcep1-3 atcep3-2 and atcep1-3 atcep2-2 double mutants have longer root hairs (RHs) than wild type (Wt) plants, suggesting that expression of AtCEPs in root trichoblasts restrains polar elongation of the RH. We provide evidence that the transcription factor NAC1 activates AtCEPs expression in roots to limit RH length. Chromatin immunoprecipitation indicates that NAC1 binds the promoter of AtCEP2 and may directly regulate its expression. Indeed, Inducible NAC1 overexpression increases AtCEP1 and AtCEP2 transcript levels in roots and leads to reduced RH growth while the loss of function nac1-2 mutation reduces AtCEP1-AtCEP3 gene expression and enhances RH growth. Likewise, expression of a dominant chimeric NAC1-SRDX repressor construct leads to increased RH length. Finally, we show that RH cell-walls in the atcep1-1 atcep3-2 double mutant have reduced levels of EXT secretion/insolubilization, suggesting that the defects in RH elongation are linked to alterations in EXT processing and accumulation. Taken together, our results support the involvement of the NAC1-AtCEP regulatory module in controlling RH polar growth through EXT processing and insolubilization at the cell wall.
展开全部
图表提取

暂无人提供速读十问回答

论文十问由沈向洋博士提出，鼓励大家带着这十个问题去阅读论文，用有用的信息构建认知模型。写出自己的十问回答，还有机会在当前页面展示哦。

Q1论文试图解决什么问题？
Q2这是否是一个新的问题？
Q3这篇文章要验证一个什么科学假设？
0
被引用
0
笔记
0
问答