About this Research Topic
Peptides are recognized as a new class of highly diverse effectors that regulate a broad range of biological processes in plants, even at femtomolar (10-15 M) concentrations. Mature peptides either derive from the processing of functional or non-functional protein precursors or are directly translated from small open reading frames (sORFs). While most peptides exert their action after being perceived by their cognate receptors, the components of the signaling cascades remain obscure in many cases and may also include more direct interactions of peptides with their targets, as in the case of antimicrobial peptides. Specific peptides and receptor pairs generate distinct readouts to orchestrate plant development, nutrient signaling, and stress responses. Studies in crops have shown that tweaking small peptides can be an effective way to boost yield by optimizing shoot meristem development, opening new routes for the application of peptide signaling research.
Substantial progress has been made in understanding plant peptide signaling during the past two decades, demonstrating specific roles of peptides in root development, nodulation, fertilization, nitrogen, and iron homeostasis, cell-to-cell communication, long-distance signaling, regulation of gene expression, and pathogen defense. In addition to peptides acting similarly to phytohormones, the analysis of plant genomes has led to the identification of genes encoding peptides that have functions distinct from their precursors, peptides derived from long non-coding RNAs (lncRNAs), and genes encoding bifunctional transcripts possessing RNA-related activities as well as activity at the peptide level. Many facets of peptide signaling remain enigmatic, in particular processes that define the boundary between coding and non-coding transcripts and the question as to how receptors recognize and distinguish different peptides that have a high sequence similarity. This difficulty is partially due to technical limitations since peptides are maintained at an extremely low level in plants, and the lack of high-sensitive biosensors renders the detection and monitoring of the peptide-receptor interaction in planta difficult. Moreover, the high diversity and various post-translational modifications of peptides exacerbate the generation of a comprehensive inventory of the plant peptidome, making the exploration of the functions of plant peptides a challenging endeavor.
The goal of this Research Topic is to present an overview of the state-of-the-art research in the field of plant peptide signaling. We welcome submissions of different types of manuscripts including original research papers, reviews, hypotheses, methods, and perspectives, including but not limited to:
• Processing of small peptides from their precursors
• Peptide perception and downstream signaling
• Post-translational modification of small peptides
• Long-distance transport of peptides
• Peptide signaling in development and responses to environmental stimuli
• Tweaking peptide signaling to boost crop yields
• Bifunctional transcripts
• Dual RNAs
• Evolution of signaling peptides and of peptide signaling
• Identification of receptors for orphan peptides
• Relating peptide structure to peptide function
Keywords: Development, Peptides, Peptide signaling, Abiotic and biotic stress signaling, Bifunctional transcripts, lncRNAs
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