Phosphorylation‐Mediated Signalling in Plants

Abstract Growth and development of a plant and its response to environmental changes requires the perception of triggers and the subsequent activation of a response. To achieve this, endless tasks and functions in any living organism are performed by proteins, and these proteins can undergo various reversible or irreversible posttranslational modifications of specific amino acid residues. One example is phosphorylation, which is a reversible modification affecting protein activity, stability, interactions, and localisation. Phosphorylation is catalysed by a specific group of enzymes, kinases, and the reverse reaction of dephosphorylation is catalysed by other enzymes, phosphatases. In this article, we discuss the tools and approaches to detect protein phosphorylation in plants. We specifically emphasise mass spectrometry‐based approaches to identify phosphopeptides and the specific phosphorylated residues. We, furthermore, illustrate the importance of phosphorylation in the life of a plant with some key examples, such as hormone signalling (specifically brassinosteroids and abscisic acid), signalling associated with the RAPID ALKALINIZATION FACTOR peptide, and signalling downstream of cold stress.