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Accumulation of endogenous peptides triggers a pathogen stress response in Arabidopsis thaliana
Author(s) -
Kmiec Beata,
Branca Rui M.M.,
Berkowitz Oliver,
Li Lu,
Wang Yan,
Murcha Monika W.,
Whelan James,
Lehtiö Janne,
Glaser Elzbieta,
Teixeira Pedro F.
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14100
Subject(s) - oligopeptidase , biology , arabidopsis thaliana , arabidopsis , effector , microbiology and biotechnology , plant defense against herbivory , biochemistry , proteomics , peptide , mitochondrion , protease , enzyme , gene , mutant
Summary The stepwise degradation of peptides to amino acids in plant mitochondria and chloroplasts is catalyzed by a network of oligopeptidases (presequence protease PreP, organellar oligopeptidase OOP ) and aminopeptidases. In the present report, we show that the lack of oligopeptidase activity in Arabidopsis thaliana results in the accumulation of endogenous free peptides, mostly of chloroplastic origin (targeting peptides and degradation products). Using mRNA sequencing and deep coverage proteomics, allowing for the identification of 17 000 transcripts and 11 000 proteins, respectively, we uncover a peptide‐stress response occurring in plants lacking PreP and OOP oligopeptidase activity. The peptide‐stress response results in the activation of the classical plant defense pathways in the absence of pathogenic challenge. The constitutive activation of the pathogen‐defense pathways imposes a strong growth penalty and a reduction of the plants reproductive fitness. Our results indicate that the absence of organellar oligopeptidases PreP1/2 and OOP results in the accumulation of peptides that are perceived as pathogenic effectors and activate the signaling pathways of plant‐defense response.