Open AccessImmunity functions of Arabidopsis pathogenesis‐related 1 are coupled but not confined to its C‐terminus processing and trafficking
Author(s) -
Pečenková Tamara,
Pejchar Přemysl,
Moravec Tomáš,
Drs Matěj,
Haluška Samuel,
Šantrůček Jiří,
Potocká Andrea,
Žárský Viktor,
Potocký Martin
Publication year - 2022
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.13187
Subject(s) - biology , nicotiana benthamiana , arabidopsis , microbiology and biotechnology , endoplasmic reticulum , arabidopsis thaliana , plant immunity , immunity , genetics , mutant , gene , immune system
The pathogenesis‐related 1 (PR1) proteins are members of the cross‐kingdom conserved CAP superfamily (from Cysteine‐rich secretory protein, Antigen 5, and PR1 proteins). PR1 mRNA expression is frequently used for biotic stress monitoring in plants; however, the molecular mechanisms of its cellular processing, localization, and function are still unknown. To analyse the localization and immunity features of Arabidopsis thaliana PR1, we employed transient expression in Nicotiana benthamiana of the tagged full‐length PR1 construct, and also disrupted variants with C‐terminal truncations or mutations. We found that en route from the endoplasmic reticulum, the PR1 protein transits via the multivesicular body and undergoes partial proteolytic processing, dependent on an intact C‐terminal motif. Importantly, only nonmutated or processing‐mimicking variants of PR1 are secreted to the apoplast. The C‐terminal proteolytic cleavage releases a protein fragment that acts as a modulator of plant defence responses, including localized cell death control. However, other parts of PR1 also have immunity potential unrelated to cell death. The described modes of the PR1 contribution to immunity were found to be tissue‐localized and host plant ontogenesis dependent.