In the 90 years since the discovery of the first peptide hormone, insulin, peptides have been recognized as important regulators of physiological functions ranging from metabolism to immune responses in mammals. Peptide Signals in Plants is a new volume in Wiley-Blackwell's Annual Plant Reviews (APR) widely recognized throughout the world as one of the leading series in plant sciences. Following an introductory chapter, the contents of Peptide Signals in Plants are broadly divided into two sections. The first section covers peptides which regulate interactions with other organisms, including the role of peptides in defense against herbivores and pathogens. The volume's second section covers peptides that regulate developmental processes, including details of the mechanisms involved in abscission, cell proliferation and stomatal patterning. With chapters written by some of the world's leading researchers and carefully drawn together and edited by Alisa Huffaker and Gregory Pearce, this is an excellent new volume in Wiley-Blackwell's Annual Plant Reviews.