title: Understanding the RALF family: a tale of many species.
abstract: Small secreted peptides are gaining importance as signalling molecules in plants. Among the 1000 open reading frames (ORFs) in the Arabidopsis (Arabidopsis thaliana) genome potentially encoding small secreted peptides, the members of the RAPID ALKALINIZATION FACTOR (RALF) family of peptides have been linked to several physiological and developmental processes. Here, we provide a comprehensive overview of current knowledge on the RALF family. Discovered in tobacco (Nicotiana tabacum), the role of RALF peptides has been investigated in numerous plant species. Together, these observations suggest that RALF peptides impact on acidification and cell expansion during growth and development. Although few components of the signalling pathway have been revealed, the recent identification of FERONIA (FER) as a RALF receptor and plasma membrane H(+)-ATPase 2 as a downstream target provide a major step forward.
authors.affiliation: Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
authors.forename: Evan
authors.initials: E
authors.lastname: Murphy
authors.affiliation: Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK; Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium. Electronic address: ivsme@psb.vib-ugent.be.
authors.forename: Ive
authors.initials: I
authors.lastname: De Smet
mesh_terms: D018506:Gene Expression Regulation, Plant; D019684:Magnoliopsida / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family; D036361:Peptide Hormones / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D036361:Peptide Hormones; D010940:Plant Proteins
keywords: FERONIA; RALF; alkalinisation; cell expansion; small signalling peptide