MINI REVIEW article
Front. Plant Sci.
Sec. Plant Physiology
Extra-Large G Proteins and Their Roles in Plant Development and Responses to Environmental Stresses
1. Agronomy, Iowa State University, Ames, United States, Iowa, 50011
2. Lovely Professional University, Phagwara, India
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Abstract
Eukaryotic G (guanine nucleotide-binding) proteins mediate important signal transduction pathways involved in diverse biological processes, including plant immunity against a wide range of pathogens. Plant signaling relies significantly on G proteins, including the Gα, Gβ, and Gγ subunits, which mediate important functions. Extra-large GTP-binding proteins (XLGs) are a subfamily of plant-specific Gα proteins that structurally resemble canonical Gα proteins but have distinct functional roles. Unlike canonical Gα proteins, XLGs lack intrinsic GTPase activity and possess an extended N-terminal region with nuclear localization signals, and interact with plasma membrane-localized receptors, suggesting their roles beyond plasma membrane signaling. XLGs play an essential role in a variety of physiological processes, such as root morphogenesis, chloroplast development, and responses to biotic and abiotic stressors. Among the XLGs, XLG1, XLG2, and XLG3 play especially vital roles with XLG2 and XLG3 involved in pathogen perception and signal transduction for activation of immune responses. XLGs interact with G-protein subunits and receptor-like kinases (RLKs), particularly FLS2 and BIK1, to form dynamic complexes involved in defense signal transduction. Several recent invesitgations demonstrate the significance of XLGs in modulating plant immunity and development suggesting their application for enhancing crop output and resilience. Understanding the mechanisms behind XLG functions may assistin the development of novel approaches to enhance plant resilience to environmental challenges. This review highlights the roles of XLG proteins in plant development and stress responses.
Summary
Keywords
extra-large GTP-binding protein (XLG), G- Proteins, plant pathogens, plant signaling, stress response, XLG3gene
Received
06 March 2026
Accepted
03 April 2026
Copyright
© 2026 MESHRAM, Akintayo and Bhattacharyya. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Madan K. Bhattacharyya
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