Arabidopsis heterotrimeric G proteins regulate immunity by directly coupling to the FLS2 receptor

  1. Xiangxiu Liang
  2. Pingtao Ding
  3. Kehui Lian
  4. Jinlong Wang
  5. Miaomiao Ma
  6. Lin Li
  7. Lei Li
  8. Meng Li
  9. Xiaojuan Zhang
  10. She Chen
  11. Yuelin Zhang
  12. Jian-Min Zhou  Is a corresponding author
  1. Chinese Academy of Sciences, China
  2. University of British Columbia, Canada
  3. National Institute of Biological Sciences, China

Abstract

The Arabidopsis immune receptor FLS2 perceives bacterial flagellin epitope flg22 to activate defenses through the central cytoplasmic kinase BIK1. The heterotrimeric G proteins composed of the non-canonical Gα protein XLG2, the Gβ protein AGB1, and the Gγ proteins AGG1 and AGG2 are required for FLS2-mediated immune responses through an unknown mechanism. Here we show that in the pre-activation state, XLG2 directly interacts with FLS2 and BIK1, and it functions together with AGB1 and AGG1/2 to attenuate proteasome-mediated degradation of BIK1, allowing optimum immune activation. Following the activation by flg22, XLG2 dissociates from AGB1 and is phosphorylated by BIK1 in the N terminus. The phosphorylated XLG2 enhances the production of reactive oxygen species (ROS) likely by modulating the NADPH oxidase RbohD. The study demonstrates that the G proteins are directly coupled to the FLS2 receptor complex and regulate immune signaling through both pre-activation and post-activation mechanisms.

Article and author information

Author details

  1. Xiangxiu Liang

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  2. Pingtao Ding

    Department of Botany, University of British Columbia, Vancouver, Canada
    Competing interests
    The authors declare that no competing interests exist.
  3. Kehui Lian

    Department of Botany, University of British Columbia, Vancouver, Canada
    Competing interests
    The authors declare that no competing interests exist.
  4. Jinlong Wang

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  5. Miaomiao Ma

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  6. Lin Li

    National Institute of Biological Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  7. Lei Li

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  8. Meng Li

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  9. Xiaojuan Zhang

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  10. She Chen

    National Institute of Biological Sciences, Beijing, China
    Competing interests
    The authors declare that no competing interests exist.
  11. Yuelin Zhang

    Department of Botany, University of British Columbia, Vancouver, Canada
    Competing interests
    The authors declare that no competing interests exist.
  12. Jian-Min Zhou

    State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
    For correspondence
    jmzhou@genetics.ac.cn
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Thorsten Nürnberger, University of Tubingen, Germany

Publication history

  1. Received: December 6, 2015
  2. Accepted: April 2, 2016
  3. Accepted Manuscript published: April 4, 2016 (version 1)
  4. Version of Record published: April 26, 2016 (version 2)

Copyright

© 2016, Liang et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Xiangxiu Liang
  2. Pingtao Ding
  3. Kehui Lian
  4. Jinlong Wang
  5. Miaomiao Ma
  6. Lin Li
  7. Lei Li
  8. Meng Li
  9. Xiaojuan Zhang
  10. She Chen
  11. Yuelin Zhang
  12. Jian-Min Zhou
(2016)
Arabidopsis heterotrimeric G proteins regulate immunity by directly coupling to the FLS2 receptor
eLife 5:e13568.
https://doi.org/10.7554/eLife.13568

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