Plant elicitor peptide 1 fortifies root cell walls and triggers a systemic root-to-shoot immune signaling in Arabidopsis

ABSTRACT

Plant immunity is initiated by cell surface-localized receptors upon perception of pathogen-derived microbe or pathogen-associated molecular patterns (MAMPs/PAMPs), damage/danger-associated molecular patterns (DAMPs), and phytocytokines. Different patterns activate highly overlapping immune signaling at the early stage but divergent physiological responses at the late stage. Here, we indicate that plant elicitor peptide 1 (Pep1), a well-known DAMP, induces lignin and callose depositions, two types of late immune responses for strengthening the plant cell wall. Pep1-induced lignin and callose depositions in Arabidopsis root rely on early signaling components for Pep1 perception and signaling propagation. The phytohormone jasmonic acid and ethylene differently regulate the Pep1-regulated cell wall consolidation. Pep1 application in root also triggers a systemic immune signaling in shoot, and reactive oxygen species (ROS) is essential for the signaling communication between root and shoot. Collectively, the study reveals that Pep1 strengthens cell walls in root and triggers a systemic immune signaling from root to shoot.

KEYWORDS:

• Arabidopsis
• plant elicitor peptide 1
• callose
• lignin
• jasmonic acid

Acknowledgments

We thank the Arabidopsis Biological Resource Center (ABRC) for providing the Arabidopsis T-DNA insertion lines, Dr Haitao Cui (Fujian Agriculture and Forestry University, China) and Dr Zhi Qi (Inner Mongolia University, China) for providing Arabidopsis mutant seeds. The work was supported by the Natural Science Foundation of Shandong Province (ZR2020MC022) to S.H., and Youth Innovation Technology Project of Higher School in Shandong Province to S.H. (2020KJF013).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author Contributions

J.Z. and Y.L. designed experiments and analyzed data; S.H. wrote the manuscript. J.Z. performed histochemical analysis and microscopy assays; Y.L. performed RT-qPCR analysis and cytosolic calcium assay. All authors have read and agreed to the published version of the manuscript.

Supplementary material

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Additional information

Funding

This work was supported by the Natural Science Foundation of Shandong Province [ZR2020MC022]; Youth Innovation Technology Project of Higher School in Shandong Province [2020KJF013].