Small Signaling Peptides in Arabidopsis Development: How Cells Communicate Over a Short Distance

Abstract

To sustain plants' postembryonic growth and development in a structure of cells fixed in cell walls, a tightly controlled short distance cell-cell communication is required. The focus on phytohormones, such as auxin, has historically overshadowed the importance of small peptide signals, but it is becoming clear that secreted peptide signals are important in cell-cell communication to coordinate and integrate cellular functions. However, of the more than 1000 potential secreted peptides, so far only very few have been functionally characterized or matched to a receptor. Here, we will describe our current knowledge on how small peptide signals can be identified, how they are modified and processed, which roles they play in Arabidopsis thaliana development, and through which receptors they act.

Phytosulfokine Regulates Growth in Arabidopsis through a Response Module at the Plasma Membrane That Includes CYCLIC NUCLEOTIDE-GATED CHANNEL17, H+-ATPase, and BAK1

“…Peptide signaling has been recognized as a central component of cell-cell communication in plants (Murphy et al, 2012). Phytosulfokine (PSK) is a pentapeptide of the sequence Tyr-Ile-Tyr-ThrGln with a sulfate group attached to each of the two tyrosine residues (Matsubayashi and Sakagami, 1996;Sauter, 2015).…”

Transcriptional and Functional Classification of the GOLVEN/ROOT GROWTH FACTOR/CLE-Like Signaling Peptides Reveals Their Role in Lateral Root and Hair Formation

“…Recent biochemical and genetic studies have shown that plant cell-to-cell communication also involves peptide signaling pathways, similar to those previously identified in animals, regulating processes as diverse as plant-pathogen interaction, cell division and expansion, meristematic stem cell homeostasis, and pollen self-incompatibility (Butenko et al, 2009;Murphy et al, 2012). The recent analysis of the Arabidopsis (Arabidopsis thaliana) genome showed that plants code for hundreds of secreted small peptides, among which are numerous potential peptide hormones (Lease and Walker, 2006).…”

Signaling Peptides in Plants

“…It is therefore likely that only a few of the total number of secreted peptides are known to date. Thus, attempts to identify new signaling peptide families in plants by various approaches are still highly valuable [4,39,40]. They can be classified in three main types of approaches: genetic, bioinformatic and biochemical assays.…”

“…Typically, several criteria are combined to search for new signaling peptide families: (i) the presence of a signal peptide sequence that would target the propeptide to the secretory pathway (for example using the SignalP algorithm, [37], (ii) the small size of the precursors, (iii) the enrichment or lack of cysteine residues in the propeptide, and (iv) the presence of sites susceptible to posttranslational modification(s). Application of one or more of the abovementioned features for in silico genome sequence searches led to the identification of multiple plant signaling peptide families including GLV/RGF/CLEL, C-TERMINALLY ENCODED PEPTIDE (CEP), IDA and CLAVATA3/ ESR-RELATED (CLE) members [4,7,9,10,22,29].…”