The 30th International Conference on Arabidopsis Research (ICAR 2019)

392 / 2019-02-22 15:47:13

PLANT NATRIURETIC PEPTIDE A and its novel receptor PNP-R2 antagonize salicylic acid-mediated signaling and cell death

PNP-A,LSD1,peptide-receptor pair,salicylic acid,cell death

Plenary track > Hormones

The plant stress hormone salicylic acid (SA) participates in local and systemic acquired resistance, which eventually leads to a whole-plant resistance toward bacterial pathogens. However, if SA-mediated signaling is not appropriately controlled, plants must pay defense-associated fitness costs such as growth inhibition and cell death. Despite its importance, to date only a few components counteracting the SA-primed cell death pathway have been identified in Arabidopsis (Arabidopsis thaliana). These include other plant hormones such as jasmonic acid and abscisic acid, apoplastic reactive oxygen species (ROS) and proteins such as LESION SIMULATING DISEASE 1 (LSD1), a transcription coregulator. Here, we describe PLANT NATRIURETIC PEPTIDE A (PNP-A), a functional analog to vertebrate atrial natriuretic peptides, which appears to antagonize both the SA-mediated signaling and the SA-primed cell death. While loss of PNP-A potentiates SA-mediated signaling, exogenous application of synthetic PNP-A or overexpression of PNP-A significantly compromises the SA-mediated immune responses. Moreover, we identified a plasma membrane-localized receptor-like protein, PNP-R2, which interacts with PNP-A and initiates the PNP-A-mediated intracellular signaling. In summary, our work identifies a novel peptide-receptor pair which counteracts both SA-mediated signaling and SA-primed cell death in Arabidopsis.