Abstract
To efficiently counteract pathogens, plants rely on a complex set of immune responses that are tightly regulated to allow the timely activation, appropriate duration and adequate amplitude of defense programs. The coordination of the plant immune response is known to require the activity of the ubiquitin/proteasome system, which controls the stability of proteins in eukaryotes. Here, we demonstrate that the N-end rule pathway, a subset of the ubiquitin/proteasome system, regulates the defense against a wide range of bacterial and fungal pathogens in the model plant Arabidopsis thaliana. We show that this pathway positively regulates the biosynthesis of plant-defense metabolites such as glucosinolates, as well as the biosynthesis and response to the phytohormone jasmonic acid, which plays a key role in plant immunity. Our results also suggest that the arginylation branch of the N-end rule pathway regulates the timing and amplitude of the defense program against the model pathogen Pseudomonas syringae AvrRpm1.
Highlights
Non-acetylated[7,8,9]
Ate[1] ate[2] plants are morphologically indistinguishable from the wild type, minimizing gene expression differences stemming from the morphological abnormalities that are observed in the mutant at later stages[16]
In agreement with the known role of ATE1/ATE2 in the control of this process[21,22], we found that almost all of the hypoxia-response genes were up-regulated in the mutant (Fig. 1c), further validating our dataset[21,24]
Summary
Non-acetylated[7,8,9] (referred to as ‘Ac/N-end rule’ or ‘Arg/N-end rule’, respectively). Proteins starting with tertiary destabilizing residues need to be modified before they are arginylated by ATE1/ATE2 and targeted for degradation by PRT610,11,15 (Fig. 1a). Because of the important role Arg-transferases play in the modification of Arg/N-end rule substrates, we hypothesized that the Arg/N-end rule pathway might be a novel regulator of plant-pathogen interactions. We show that several components of the Arg/N-end rule pathway are involved in the defense of plants against a wide range of pathogens, including bacteria and fungi with different lifestyles. We demonstrate that the arginylation branch of the Arg/N-end rule pathway promotes the biosynthesis of glucosinolates and JA, which play important roles in the defense of plants against pathogens[1,23], as well as the plant’s response to JA. Our work further suggests that arginylation plays a role in regulating the timing and amplitude of the immune response following inoculation with the model pathogen Pseudomonas syringae AvrRpm[1], possibly through modulation of phytohormone signaling pathways
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
