Xanthomonas natriuretic peptide is recognized by the Arabidopsis natriuretic peptide receptor 1 and through this interaction triggers similar plant responses to its plant counterpart

Abstract

Plant natriuretic peptides (PNPs) are hormone peptides that participate in the regulationof ions and water homeostasis in plants. Xanthomonas citri subsp. citri (Xcc) the causalagent of citrus canker disease also possesses a PNP-like peptide (XacPNP). Thispeptide, similarly to AtPNP-A, the most studied PNP from Arabidopsis thaliana, causesstomatal aperture and enhances photosynthetic efficiency in plant leaves. Thus, thefunction that has been attributed to XacPNP is to contribute to maintain photosyntheticefficiency and water homeostasis in plant tissue during the infection process, to createfavorable conditions for biotrophic pathogens survival. A PNP receptor (AtPNP-R1) forAtPNP-A has been identified and the AtPNP-A activity in regulation of waterhomeostasis has been observed to depend on the presence of AtPNP-R1. Here, wedemonstrated that both AtPNP-A and XacPNP require the presence of AtPNP-R1 to induce plant stomatal aperture. Also, less necrotic tissue was found in infections withpathogens expressing XacPNP and this was dependent on the presence of AtPNP-R1,suggesting that XacPNP interacts with this receptor to exert its function. Finally, weconfirmed that AtPNP-A and XacPNP interact with AtPNP-R1 in planta, which supportthe idea that XacPNP triggers similar plant responses to its plant counterpart.