Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
The N‐end rule pathway is a highly conserved constituent of the ubiquitin proteasome system, yet little is known about its biological roles.Here we explored the role of the N‐end rule pathway in the plant immune response. We investigated the genetic influences of components of the pathway and known protein substrates on physiological, biochemical and metabolic responses to pathogen infection.We show that the glutamine (Gln) deamidation and cysteine (Cys) oxidation branches are both components of the plant immune system, through the E3 ligase PROTEOLYSIS (PRT)6. In Arabidopsis thaliana Gln‐specific amino‐terminal (Nt)‐amidase (NTAQ1) controls the expression of specific defence‐response genes, activates the synthesis pathway for the phytoalexin camalexin and influences basal resistance to the hemibiotroph pathogen Pseudomonas syringae pv tomato (Pst). The Nt‐Cys ETHYLENE RESPONSE FACTOR VII transcription factor substrates enhance pathogen‐induced stomatal closure. Transgenic barley with reduced HvPRT6 expression showed enhanced resistance to Ps. japonica and Blumeria graminis f. sp. hordei, indicating a conserved role of the pathway.We propose that that separate branches of the N‐end rule pathway act as distinct components of the plant immune response in flowering plants.
Publikation
Rajjou, L.; Rivas, S.; Graciet, E.;Life and death of proteins after protease cleavage: protein degradation by the N-end rule pathwayNew Phytol.218929-935(2018)DOI: 10.1111/nph.14619
The N‐end rule relates the stability of a protein to the identity of its N‐terminal residue and some of its modifications. Since its discovery in the 1980s, the repertoire of N‐terminal degradation signals has expanded, leading to a diversity of N‐end rule pathways. Although some of these newly discovered N‐end rule pathways remain largely unexplored in plants, recent discoveries have highlighted roles of N‐end rule‐mediated protein degradation in plant defense against pathogens and in cell proliferation during organ growth. Despite this progress, a bottleneck remains the proteome‐wide identification of N‐end rule substrates due to the prerequisite for endoproteolytic cleavage and technical limitations. Here, we discuss the recent diversification of N‐end rule pathways and their newly discovered functions in plant defenses, stressing the role of proteases. We expect that novel proteomics techniques (N‐terminomics) will be essential for substrate identification. We review these methods, their limitations and future developments.