Heterotrimeric G proteins serve as a converging point in plant defense signaling activated by multiple receptor-like kinases

Liu, Jinman, Ding, Pingtao, Sun, Tongjun, Nitta, Yukino, Dong, Oliver, Huang, Xingchuan, Yang, Wei, Li, Xin, Botella, Jose Ramon and Zhang, Yuelin (2013) Heterotrimeric G proteins serve as a converging point in plant defense signaling activated by multiple receptor-like kinases. Plant Physiology, 161 4: 2146-2158. doi:10.1104/pp.112.212431


Author Liu, Jinman
Ding, Pingtao
Sun, Tongjun
Nitta, Yukino
Dong, Oliver
Huang, Xingchuan
Yang, Wei
Li, Xin
Botella, Jose Ramon
Zhang, Yuelin
Title Heterotrimeric G proteins serve as a converging point in plant defense signaling activated by multiple receptor-like kinases
Journal name Plant Physiology   Check publisher's open access policy
ISSN 0032-0889
1532-2548
Publication date 2013-04-01
Year available 2013
Sub-type Article (original research)
DOI 10.1104/pp.112.212431
Open Access Status Not yet assessed
Volume 161
Issue 4
Start page 2146
End page 2158
Total pages 13
Place of publication Rockville, MD, United States
Publisher American Society of Plant Biologists
Language eng
Abstract In fungi and metazoans, extracellular signals are often perceived by G-protein-coupled receptors (GPCRs) and transduced through heterotrimeric G-protein complexes to downstream targets. Plant heterotrimeric G proteins are also involved in diverse biological processes, but little is known about their upstream receptors. Moreover, the presence of bona fide GPCRs in plants is yet to be established. In Arabidopsis (Arabidopsis thaliana), heterotrimeric G protein consists of one G alpha subunit (G PROTEIN alpha-SUBUNIT1), one G beta subunit (ARABIDOPSIS G PROTEIN beta-SUBUNIT1 [AGB1]), and three G gamma s subunits (ARABIDOPSIS G PROTEIN gamma-SUBUNIT1 [AGG1], AGG2, and AGG3). We identified AGB1 from a suppressor screen of BAK1-interacting receptor-like kinase1-1 (bir1-1), a mutant that activates cell death and defense responses mediated by the receptor-like kinase (RLK) SUPPRESSOR OF BIR1-1. Mutations in AGB1 suppress the cell death and defense responses in bir1-1 and transgenic plants overexpressing SUPPRESSOR OF BIR1-1. In addition, agb1 mutant plants were severely compromised in immunity mediated by three other RLKs, FLAGELLIN-SENSITIVE2 (FLS2), Elongation Factor-TU RECEPTOR (EFR), and CHITIN ELICITOR RECEPTOR KINASE1 (CERK1), respectively. By contrast, G PROTEIN alpha-SUBUNIT1 is not required for either cell death in bir1-1 or pathogen-associated molecular pattern-triggered immunity mediated by FLS2, EFR, and CERK1. Further analysis of agg1 and agg2 mutant plants indicates that AGG1 and AGG2 are also required for pathogen-associated molecular pattern-triggered immune responses mediated by FLS2, EFR, and CERK1, as well as cell death and defense responses in bir1-1. We hypothesize that the Arabidopsis heterotrimeric G proteins function as a converging point of plant defense signaling by mediating responses initiated by multiple RLKs, which may fulfill equivalent roles to GPCRs in fungi and animals.
Formatted abstract
In fungi and metazoans, extracellular signals are often perceived by G-protein-coupled receptors (GPCRs) and transduced through heterotrimeric G-protein complexes to downstream targets. Plant heterotrimeric G proteins are also involved in diverse biological processes, but little is known about their upstream receptors. Moreover, the presence of bona fide GPCRs in plants is yet to be established. In Arabidopsis (Arabidopsis thaliana), heterotrimeric G protein consists of one Gα subunit (G PROTEIN α-SUBUNIT1), one Gβ subunit (ARABIDOPSIS G PROTEIN β-SUBUNIT1 [AGB1]), and three Gγs subunits (ARABIDOPSIS G PROTEIN γ-SUBUNIT1 [AGG1], AGG2, and AGG3). We identified AGB1 from a suppressor screen of BAK1-interacting receptor-like kinase1-1 (bir1-1), a mutant that activates cell death and defense responses mediated by the receptor-like kinase (RLK) SUPPRESSOR OF BIR1-1. Mutations in AGB1 suppress the cell death and defense responses in bir1-1 and transgenic plants overexpressing SUPPRESSOR OF BIR1-1. In addition, agb1 mutant plants were severely compromised in immunity mediated by three other RLKs, FLAGELLIN-SENSITIVE2 (FLS2), Elongation Factor-TU RECEPTOR (EFR), and CHITIN ELICITOR RECEPTOR KINASE1 (CERK1), respectively. By contrast, G PROTEIN α-SUBUNIT1 is not required for either cell death in bir1-1 or pathogen-associated molecular pattern-triggered immunity mediated by FLS2, EFR, and CERK1. Further analysis of agg1 and agg2 mutant plants indicates that AGG1 and AGG2 are also required for pathogen-associated molecular pattern-triggered immune responses mediated by FLS2, EFR, and CERK1, as well as cell death and defense responses in bir1-1. We hypothesize that the Arabidopsis heterotrimeric G proteins function as a converging point of plant defense signaling by mediating responses initiated by multiple RLKs, which may fulfill equivalent roles to GPCRs in fungi and animals.
Keyword Agrobacterium mediated transformation
Pseudomonas syringae effector
Systemic acquired resistance
Innate immunity
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID 2011CB100700
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Agriculture and Food Sciences
Official 2014 Collection
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 76 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 79 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 05 May 2013, 11:38:30 EST by System User on behalf of Scholarly Communication and Digitisation Service