《植物生理学报》 2017, 53(8): 1383-1391

拟南芥低磷诱导根构型重塑不敏感突变体ipr1的筛选和初步分析

隋立乾, 刘栋^*

清华大学生命科学学院, 北京100084

通信作者：刘；E-mail: liu-d@mail.tsinghua.edu.cn

摘　要：

植物在缺磷条件下, 会做出一系列的应答反应以维持自身磷稳态, 其中一个重要的应答反应是根构型的重塑。本文报道一个对低磷胁迫诱导的根构型重塑表现为不敏感的拟南芥突变体ipr1。对ipr1的生长和生理表型的分析表明, IPR1只参与了局部的低磷信号对植物生长发育的调控。als3是一个对低磷胁迫诱导根构型重塑超敏的突变体, 其突变表型是由于其根部表面超积累Fe³⁺引起的。与之相反, ipr1根表面较野生型积累较少的Fe³⁺。遗传分析表明, IPR1作用于ALS3下游, 通过调控根表面积累的Fe³⁺水平来影响植物对低磷胁迫的敏感性。ipr1突变体为进一步解析低磷胁迫诱导根构型重塑的分子机制提供了理想的实验材料。

关键词：低磷胁迫; 根构型重塑; ipr1; Fe³⁺积累

收稿：2017-06-15   修定：2017-07-20

资助：国家自然科学基金面上项目(31670256)。

Identification and characterization of an Arabidopsis mutant which is insensitive to low phosphate induced-remodeling of root architecture

SUI Li-Qian, LIU Dong^*

School of Life Sciences, Tsinghua University, Beijing 100084, China

Corresponding author: LIU Dong; E-mail: liu-d@mail.tsinghua.edu.cn

Abstract:

Plants respond to phosphate (Pi) deficiency by triggering a suite of adaptive responses to maintain Pi homeostasis. One major response is the remodeling of root architecture. Here, we report the characterization of an Arabidopsis mutant ipr1 (insensitive phosphate root 1). ipr1 is insensitive to Pi deficiency-induced remodeling of root architecture. Phenotypic analyses indicated that IPR1 only functions in local Pi signaling to regulate plant growth and development. Arabidopsis als3 (aluminum sensitive 3) mutant is hypersensitive to Pi deficiency-induced remodeling of root architecture. Its mutant phenotypes are resulted from the overaccumulation of Fe³⁺ on its root surface. In contrast, ipr1 accumulates less Fe³⁺ on its root surface than wild type plants. Genetic analyses showed that IPR1 acts downstream of ALS3 to regulate plant Pi sensitivity by modulating Fe³⁺ level in roots. Thus, ipr1 will be an ideal material for investigating the molecular mechanism of Pi deficiency-induced remodeling of root architecture.

Key words: low-phosphate stress; remodeling of root architecture; ipr1; accumulation of Fe³⁺