Receptor-Like Kinases and Environmental Stress in Plants

Abstract

Various biotic and abiotic environmental stresses negatively affect the diverse aspects of plant growth and development, and crop productivity. Plants being sessile organisms have developed effective strategies to avoid, tolerate, or acclimatized to various kinds of stress conditions. Several stress factors of plants activate cellular responses and signaling pathways such as secretion of stress proteins. Receptor-like kinases (RLKs) is a class of defense-related proteins comprising more than a thousand members. The RLKs mostly consisted of an extracellular domain for signal perception, a transmembrane domain to anchor the protein into membrane and a cytoplasmic serine/threonine kinase domain for stimulating the immunity of plants. They are known to play a diverse range of functions in plants, ranging from growth and development to responses against various environmental stresses. RLK signaling is arbitrated by phosphorylation events which take place amid proteins present in receptor complexes. Several RLKs such as BR1, CLAVATA1, S-locus receptor kinase, Flagellin Insensitive 2, etc. provide fruitful information on the roles arbitrated by the members of RLK gene family. Plants recognize numerous number of RLKs as pattern recognition receptors (PRRs) which detect host and microbe-derived molecular patterns as the first layer of inducible defense. The studies have revealed the mechanism of PRR activation and signaling and their ligands. In this chapter, the systematic analyses of plant RLKs responses to different stresses have been explained in detail.