The E3 ligase MREL57 modulates microtubule stability and stomatal closure in response to ABA

• Published in: Nature communications Vol. 12; no. 1; pp. 2181 - 15
• Main Authors: Dou, Liru, He, Kaikai, Peng, Jialin, Wang, Xiangfeng, Mao, Tonglin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.04.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 14; 14/35; 14/63; 631/449; 631/449/2661/2146; 631/449/448/1408; 631/449/448/2189; 82/1; 82/80; 82/83; Abscisic acid; Abscisic Acid - pharmacology; Arabidopsis - drug effects; Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; Closures; Cytoskeleton; Dismantling; Drought; Environmental stress; Green Fluorescent Proteins - metabolism; Humanities and Social Sciences; Microtubules - drug effects; Microtubules - metabolism; Models, Biological; Modules; multidisciplinary; Mutation - genetics; Phenotypes; Plant Stomata - cytology; Plant Stomata - drug effects; Plant Stomata - metabolism; Plants, Genetically Modified; Proteasome 26S; Protein Binding - drug effects; Proteins; Proteolysis - drug effects; Science; Science (multidisciplinary); Seedlings - drug effects; Seedlings - metabolism; Stomata; Ubiquitin; Ubiquitin - metabolism; Ubiquitin-protein ligase; Ubiquitin-Protein Ligases - metabolism; Ubiquitination - drug effects
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-22455-y

Regulation of stomatal movement is critical for plant adaptation to environmental stresses. The microtubule cytoskeleton undergoes disassembly, which is critical for stomatal closure in response to abscisic acid (ABA). However, the mechanism underlying this regulation largely remains unclear. Here we show that a ubiquitin-26S proteasome (UPS)-dependent pathway mediates microtubule disassembly and is required for ABA-induced stomatal closure. Moreover, we identify and characterize the ubiquitin E3 ligase MREL57 (MICROTUBULE-RELATED E3 LIGASE57) and the microtubule-stabilizing protein WDL7 (WAVE-DAMPENED2-LIKE7) in Arabidopsis and show that the MREL57-WDL7 module regulates microtubule disassembly to mediate stomatal closure in response to drought stress and ABA treatment. MREL57 interacts with, ubiquitinates and degrades WDL7, and this effect is clearly enhanced by ABA. ABA-induced stomatal closure and microtubule disassembly are significantly suppressed in mrel57 mutants, and these phenotypes can be restored when WDL7 expression is decreased. Our results unravel UPS-dependent mechanisms and the role of an MREL57-WDL7 module in microtubule disassembly and stomatal closure in response to drought stress and ABA. During stomatal opening and closing, the guard cell microtubule cytoskeleton is reorganised. Here the authors show that the E3 ubiquitin ligase MREL57 targets the microtubule stabilizing protein WDL7 to promote microtubule disassembly during ABA-induced stomatal closure.