植物学报 ›› 2020, Vol. 55 ›› Issue (2): 126-136.DOI: 10.11983/CBB19242

• 研究报告 • 上一篇    下一篇

磷酸肌醇激酶FAB1调控拟南芥根毛伸长

姚玉婷,马家琦,冯晓莉,潘建伟,王超()   

  1. 兰州大学生命科学学院, 细胞活动与逆境适应教育部重点实验室, 兰州 730000
  • 收稿日期:2019-12-16 接受日期:2020-02-17 出版日期:2020-03-01 发布日期:2020-02-17
  • 通讯作者: 王超
  • 基金资助:
    国家自然科学基金(31801193);国家自然科学基金重大研究计划-细胞器-培育(No.91754104);国家自然科学基金国际地区合作研究(No.31820103008);兰州大学“中央高校基本科研业务费专项资金”自由探索项目(No.lzujbky-2018-28)

A Role of Arabidopsis Phosphoinositide Kinase, FAB1, in Root Hair Growth

Yuting Yao,Jiaqi Ma,Xiaoli Feng,Jianwei Pan,Chao Wang()   

  1. Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
  • Received:2019-12-16 Accepted:2020-02-17 Online:2020-03-01 Published:2020-02-17
  • Contact: Chao Wang

摘要: FAB1/PIKfyve是介导PI(3,5)P2 (磷脂酰肌醇3,5-二磷酸)生物合成的磷酸肌醇激酶。在动物和酵母(Saccharomyces cerevisiae)中, PI(3,5)P2参与调控胞内膜运输, 但在植物中的研究较少。该文通过分析拟南芥(Arabidopsis thaliana) FAB1的T-DNA插入突变体的表型解析PI(3,5)P2的生物学功能。拟南芥FAB1基因家族包含FAB1AFAB1BFAB1CFAB1D四个基因。研究发现, fab1a/b呈现雄配子体致死的表型。利用遗传杂交获得fab1b/c/d三突变体, 发现FAB1BFAB1CFAB1D功能缺失导致根毛相比野生型变短, 经FAB1特异性抑制剂YM201636处理后的野生型中也观察到相似的短根毛表型。此外, fab1b/c/d三突变体中DR5转录水平降低。同时, 外源施加生长素类似物2,4-D和NAA能部分恢复fab1b/c/d植株短根毛的表型, 但fab1b/c/d突变体对生长素转运抑制剂(1-NOA和TIBA)的敏感性与野生型相似。此外, FAB1B/C/D功能缺失使根毛中ROS的含量减少且影响肌动蛋白的表达。上述结果表明, FAB1B/C/D通过调控生长素分布、ROS含量和肌动蛋白的表达影响拟南芥根毛伸长。

关键词: FAB1, 根毛, 生长素, 活性氧, 肌动蛋白, 拟南芥

Abstract: Lipid kinase FORMATION of APLOID and BINUCLEATE CELLS 1 (FAB1/PIKfyve) is a key enzyme that generates PI(3,5)P2. PI(3,5)P2 plays an important role in regulating membrane trafficking in yeast and animal cells, but its function in plants remains poorly understood. Here we study the functional role of PI(3,5)P2 via analysis of phenotypes of Arabidopsis FAB1 T-DNA knockout lines. The Arabidopsis FAB1 family contains four orthologous genes: FAB1A, FAB1B, FAB1C, and FAB1D. The fab1a/b double mutant showed a complete male gametophyte lethal phenotype. fab1b/c/d mutant was successfully isolated. Genetic analyses showed that the loss of FAB1B, FAB1C and FAB1D function disrupts root hairs elongation. Further pharmacological analysis showed that the FAB1-specific inhibitor YM201636 inhibited the root hairs growth. In addition, the transcription level of DR5-GFP, an indicator of auxin expression and distribution, was downregulated in single mutation of FAB1B, FAB1C and FAB1D. Moreover, triple mutant phenotypes (short root hairs) were partially rescued by exogenous application of auxin analog 2,4-D and NAA. However, the mutant’s sensitivity to 1-NOA (auxin influx inhibitor) and TIBA (auxin efflux inhibitor) in root hair elongation assay is identical to that of the wild-type. Furthermore, loss of FAB1B, FAB1C and FAB1D function reduces the level of reactive oxygen species (ROS) and affects actin expression in root hairs. Taken together, the FAB1B/C/D affects Arabidopsis root hair elongation by regulating auxin distribution, levels of ROS, and actin expression.

Key words: FAB1, root hair, auxin, ROS, actin, Arabidopsis thaliana