Post-transkriptionale Regulation der Phytohormon Signaltransduktion in der Arabidopsis Immunabwehr
Organismische Interaktionen, chemische Ökologie und Mikrobiome pflanzlicher Systeme
Zusammenfassung der Projektergebnisse
An organism continuously experiences shift in biological states necessitating extensive rearrangement of physiology and molecular order of the cell. Here we model transitions between optimal growth conditions, fully induced pattern triggered immunity (PTI) and back in the model plant Arabidopsis thaliana, chronologically measuring changes in transcript, protein, phytohormone abundance and protein synthesis and degradation rates of 99 targets using qPCR an LC-MS parallel reaction monitoring (PRM). Temporally changing synthesis and degradation rates were primary determinants of abundance, next to changes in mRNA levels, of tryptophane, glucosinolate (GS), JA biosynthesis and photosynthesis associated (PAP) proteins particularly in the earlier establisher phases but also in fully induced, deep PTI. While transcripts returned to growth levels 3 to 16 hours post elicitation, protein levels remained at fully induced PTI levels up to 16 hours into the transitory phase back to optimal growth. A notable exception were polar auxin transporters PIN3 and PIN7 levels which decreased in PTI but quickly returned to initial growth levels after transition, although global auxin levels only decreased by 20%. Tryptophane, GS and JA biosynthesis proteins all increased in abundance in the wild type and the myc234 mutant background linking induction of the tryptophane and GS biosynthesis pathways to flg22 treatment and PTI independent of MYC2 and homologs. PAPs abundance was depleted in fully induced PTI however not in the myc234 mutant linking this active immune response to JA signaling. FERREDOXIN-NADP(+)-OXIDOREDUCTASE (FNR1) synthesis rates decreased while its degradation rate increased. FNR1 is the penultimate protein in the photosynthetic electron transfer chain and imparts electrons onto NADP+ however in its absence electrons are used for oxygen photoreduction and H2O2 production, an active defense compound. Thus FNR1 may be the molecular switch that switches photosystem activity between growth and defense under post-transcriptional control. The myc234 mutation generally led to delayed changes in transcript and protein abundance but did not affect protein turn-over.
Projektbezogene Publikationen (Auswahl)
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Reshaping of the Arabidopsis thaliana Proteome Landscape and Co-regulation of Proteins in Development and Immunity. Mol Plant. 2020 Dec 7;13(12):1709-1732
Bassal M1, Abukhalaf M1, Majovsky P, Thieme D, Herr T, Ayash M, Tabassum N, Al Shweiki MR, Proksch C, Hmedat A, Ziegler J, Lee J, Neumann S, Hoehenwarter W
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LC-MS Based Draft Map of the Arabidopsis thaliana Nuclear Proteome and Protein Import in Pattern Triggered Immunity. Front Plant Sci. 2021 Nov 8;12:744103
Ayash M1, Abukhalaf M1, Thieme D, Proksch C, Heilmann M, Schattat MH, Hoehenwarter W
