J Integr Plant Biol ›› 2023, Vol. 65 ›› Issue (10): 2380-2394.DOI: 10.1111/jipb.13551

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  • 收稿日期:2023-03-21 接受日期:2023-07-31 出版日期:2023-10-01 发布日期:2023-11-01

Arabidopsis RNA polymerase II C-terminal domain phosphatase-like 1 targets mitogen-activated protein kinase cascades to suppress plant immunity

Junjun Wei1†, Wei Sun1†, Xinhang Zheng1, Shanshan Qiu1, Shuangyu Jiao1, Kevin Babilonia2, Hisashi Koiwa3, Ping He2, Libo Shan2, Wenxian Sun1 and Fuhao Cui1*   

  1. 1. Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China;
    2. Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA;
    3. Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA
    †These authors contributed equally to this work.
    *Correspondence: Fuhao Cui (cuifuhao@163.com)
  • Received:2023-03-21 Accepted:2023-07-31 Online:2023-10-01 Published:2023-11-01

Abstract: Mitogen-activated protein kinase (MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1 (C-terminal domain phosphatase-like 1) as a negative regulator of microbe-associated molecular pattern (MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide flg22. Furthermore, flg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with flg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefly luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.

Key words: Arabidopsis, C-terminal domain (CTD) phosphatase-like 1 (CPL1), microbe-associated molecular pattern (MAMP), mitogen-activated protein kinase (MAPK), pattern-triggered immunity (PTI)

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