Emerging Role of Plant GSK3/SHAGGY‐like Protein Kinases in Stress Signaling Pathways

Plant GSK3-like kinases are key players in several crucial signaling pathways and their physiological role has emerged initially with the identification of BIN2 (Brassinosteroid Insensitive 2) in Brassinosteroid (BR) signal transduction pathway. They are known to modulate protein phosphorylation and differential complex formation. However, little information is available on functional regulation of Glycogen Synthase Kinase 3 (GSK3)-like kinases, especially their upstream and downstream regulators, which enable them to regulate myriads of cellular processes including cell growth, root, and stomatal development, light response, flower development, stress, and abscisic acid (ABA) responses. With time, addition of novel substrate of GSK3-like kinases in the literature indulge a need to corroborate this information. Therefore, at first a phylogenetic approach was taken to understand and trace their evolutionary history and it depicted how they diverged very early in flowering plants and later their duplication led to multiple members of GSK3-like kinases in plants. Also, we have combined the progress made in recent years in understanding the versatile role of plant GSK3-like kinases majorly in stress signaling including abiotic, biotic stress, and their connection with plant growth regulators. An attempt has been made to elaborate their newly identified substrate in stress conditions, with special emphasis on their physiological and biochemical relevance in cellular signaling in plants.