Plant elicitor Peptides regulate root hair development in Arabidopsis

Abstract

Plant Elicitor Peptides (Peps) induce plant immune responses and inhibit root growth through their receptors PEPR1 and PEPR2, two receptor-like kinases. In our study, we found a previously unknown function of Peps that enhance root hair growth in a PEPRs-independent manner. When we characterized the expression patterns of <i>PROPEP</i> genes, we found several gene promoters of <i>PROPEP</i> gene family were particularly active in root hairs. Furthermore, we observed that <i>PROPEP2</i> is vital for root hair development, as disruption of <i>PROPEP2</i> gene led to a significant reduction in root hair density and length. We also discovered that <i>PROPEP2</i> regulates root hair formation via the modulation of <i>CPC</i> and <i>GL2</i> expression, thereby influencing the cell-fate determination of root hairs. Additionally, calcium signaling appeared to be involved in PROPEP2/Pep2-induced root hair growth. These findings shed light on the function of Peps in root hair development.