Receptor Ligands in Development

Abstract

Although there are hundreds of genes encoding receptor-like kinases and putative secreted ligands, to date less that ten have been matched and been shown to control plant growth or development. Brassionsteroids (BRs) and peptide ligands are involved in signaling between cells in the close vicinity to each other, and not transported over long distances. BRs and sulfated peptide ligands (PSK and PSY) have growth-promoting activities, while cysteine-rich and proline-rich peptide ligands identified so far are involved in specific processes such as self-incompatibility, differentiation, meristem maintenance and cell separation. Here we review how ligands in development and their respective receptors have been identified, how they interact, as well as the functional redundancy found in ligand gene families.