Role of leucine-rich repeat receptor-like kinases in abiotic and biotic stress responses in plants

Plants have evolved a series of specialized membrane receptor kinases which sense the diversity of extracellular stimuli and activate the downstream signaling pathways. These receptor kinases coordinate various growth and developmental processes and constitute the first line of the defense system in plants, as well. The leucine-rich repeat receptor-like kinases (LRR-RLKs) forms an important and the largest family of the receptor-like kinases (RLK) superfamily, which has more than 200 LRR-RLK members in Arabidopsis. LRR-RLKs regulate a wide range of biological processes such as secondary growth, regulation of meristem development, microsporogenesis and embryogenesis, brassinosteroid signaling, stomatal development and organ size regulation, cell wall development, etc., and in-plant immune response against various pathogens and also provide tolerance against various abiotic stresses like heat, low temperature, osmotic, gamma radiation, salt stress, and abscisic acid (ABA) and hydrogen peroxide (H2O2) treatments. This chapter aims to elaborate on the structural details and various roles of LRR-RLKs in plants.