AtPep3 is a hormone-like peptide that plays a role in the salinity stress tolerance of plants

Abstract

Peptides encoded by small coding genes play an important role in plant development, acting in a similar manner as phytohormones. Few hormone-like peptides, however, have been shown to play a role in abiotic stress tolerance. In the current study, 17 genes coding for small peptides were found to be up-regulated in response to salinity stress. To identify peptides leading salinity stress tolerance, we generated transgenic plants overexpressing these small coding genes and assessed survivability and root growth under salinity stress conditions. Results indicated that 4 of the 17 overexpressed genes increased salinity stress tolerance. Further studies focused on , which was the most highly up-regulated gene under salinity stress. Treatment of plants with synthetic peptides encoded by revealed that a C-terminal peptide fragment (AtPep3) inhibited the salt-induced bleaching of chlorophyll in seedlings. Conversely, knockdown transgenic plants exhibited a hypersensitive phenotype under salinity stress, which was complemented by the AtPep3 peptide. This functional AtPep3 peptide region overlaps with an AtPep3 elicitor peptide that is related to the immune response of plants. Functional analyses with a receptor mutant of AtPep3 revealed that AtPep3 was recognized by the PEPR1 receptor and that it functions to increase salinity stress tolerance in plants. Collectively, these data indicate that AtPep3 plays a significant role in both salinity stress tolerance and immune response in.

Pattern recognition receptors confer plant salt tolerance via WRKY18/WRKY40 transcription factors

“…PEPR1 recognizes all Pep peptides while PEPR2 recognizes only Pep1 and Pep2 (Krol et al, 2010;Bartels et al, 2013). Although it was previously described that PEPR1, but not PEPR2, is required for Pep3-triggered salt tolerance (Nakaminami et al, 2018), our analysis showed that Pep1-triggered salt tolerance was retained in pepr1 or pepr2 but abolished in pepr1 pepr2 plants ( Figures 1A, 1C, Table 1). This indicates that PEPR1 and PEPR2 both mediate salt tolerance, despite their differences in Pep ligand specificity.…”

“…These studies suggest that CERK1 has a role in promoting salt stress tolerance, and that this function is related to an as-yetunidentified endogenous DAMP(s). Likewise, PROPEP3 overexpression and Pep3 application under sterile conditions both enhance salt tolerance through PEPR1 (Nakaminami et al, 2018). These studies suggest that DAMP sensing and signaling contribute to salt stress tolerance, yet the underling mechanisms are not defined.…”

MtSSPdb: The Medicago truncatula Small Secreted Peptide Database

“…SSPs have emerged as an important class of regulatory molecules involved in plant growth, development, plant-microbe interactions, and stress tolerance (Czyzewicz et al, 2013, Nakaminami et al, 2018, Takahashi et al, 2018. This is of particular significance for legumes, since recent discoveries show that SSPs regulate symbiotic root nodulation (Djordjevic et al, 2015, Nishida et al, 2018, Kereszt et al, 2018, and root development (Araya et al, 2016, Patel et al, 2018.…”

Identification and Functional Investigation of Genome‐Encoded, Small, Secreted Peptides in Plants

“…Small secreted peptides (SSPs) encoded in plant genomes, also termed peptide hormones, possess crucial roles in plant growth and development (Breiden & Simon 2016;Murphy, Smith, & De Smet, 2012;Patel et al, 2018). Plant SSPs have also been shown to be important regulators of stress tolerance (Nakaminami et al, 2018;Takahashi et al, 2018) and nutrient acquisition (Grillet, Lan, Li, Mokkapati, & Schmidt, 2018;Tabata et al, 2014). In light of their diverse and powerful effects on plant development and stress physiology, SSPs are of great interest for fundamental plant biology and may hold potential for yield improvements in agriculture.…”