Plant phospholipase Ds (PLDs), essential regulators of phospholipid signaling, function in multiple signal transduction cascades; however, the mechanisms regulating PLDs in response to pathogens remain unclear. Here, we found that Arabidopsis (Arabidopsis thaliana) PLDδ accumulated in cells at the entry sites of the barley powdery mildew fungus, Blumeria graminis f. sp hordei Using fluorescence recovery after photobleaching and single-molecule analysis, we observed higher PLDδ density in the plasma membrane after chitin treatment; PLDδ also underwent rapid exocytosis. Fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy showed that the interaction between PLDδ and the microdomain marker AtREMORIN1.3 (AtREM1.3) increased in response to chitin, indicating that exocytosis facilitates rapid, efficient sorting of PLDδ into microdomains upon pathogen stimulus. We further unveiled a trade-off between brefeldin A (BFA)-resistant and -sensitive pathways in secretion of PLDδ under diverse conditions. Upon pathogen attack, PLDδ secretion involved syntaxin-associated VAMP721/722-mediated exocytosis sensitive to BFA. Analysis of phosphatidic acid (PA), hydrogen peroxide, and jasmonic acid (JA) levels and expression of related genes indicated that the relocalization of PLDδ is crucial for its activation to produce PA and initiate reactive oxygen species and JA signaling pathways. Together, our findings revealed that the translocation of PLDδ to papillae is modulated by exocytosis, thus triggering PA-mediated signaling in plant innate immunity.plantcell;31/12/3015/FX1F1fx1.

• MeSH
• Arabidopsis genetika   imunologie   metabolismus   mikrobiologie   MeSH
• Ascomycota patogenita   MeSH
• brefeldin A imunologie   metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• chitin imunologie   metabolismus   MeSH
• cyklopentany metabolismus   MeSH
• exocytóza účinky léků   imunologie   MeSH
• fosfolipasa D genetika   metabolismus   MeSH
• kyseliny fosfatidové metabolismus   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• oxylipiny metabolismus   MeSH
• peroxid vodíku metabolismus   MeSH
• přirozená imunita * účinky léků   MeSH
• proteiny huseníčku metabolismus   MeSH
• proteiny Qa-SNARE metabolismus   MeSH
• proteiny R-SNARE metabolismus   MeSH
• proteiny SNARE genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce imunologie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Trafficking of the rhoptry chimeric protein RhopH2-GFP, which contains RhopH2 signal peptide plus the downstream five amino acids, was dissected by treating parasites with Brefeldin A at three different time points. Twenty eight hrs-stage trophozoites accumulated the chimera within the parasite endoplasmic reticulum. In 32 hrs-stage schizonts, the chimera was distributed in the parasite cytoplasm but not in the parasitophorous vacuole. In 36 hrs stage-schizonts, the chimera was detected in individual structures around the developing merozoites and, in contrary to non-treated parasites, no immature rhoptry vesicles could be detected in the cytoplasm of immature merozoites. These data show that this chimera is trafficked to the rhoptries via Brefeldin A-sensitive pathway indicating that this trafficking is similar to that of the endogenous rhoptry proteins, and that the five amino acids downstream of the signal peptide cleavage site may contain the sorting signal required for rhoptry targeting.

• MeSH
• brefeldin A chemie   metabolismus   MeSH
• inhibitory syntézy proteinů chemie   metabolismus   MeSH
• Plasmodium falciparum metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• regulace genové exprese fyziologie   MeSH
• rekombinantní proteiny metabolismus   MeSH
• transport proteinů * MeSH
• Publikační typ
• časopisecké články MeSH