The receptor-like pseudokinase GHR1 is required for stomatal closure

Maija Elina Sierla, Hanna Hõrak, Kirk Loren Overmyer, Cezary Marcin Waszczak, Dmitry Yarmolinsky, Tobias Maierhofer, Julia Vainonen, Konstantin Denessiouk, Jarkko Tapani Salojärvi, Kristiina Laanemets, Kadri Tõldsepp, Triin Vahisalu, Adrien Guy Bernard Gauthier, Tuomas Puukko, Lars Paulin, Petri Olli Viljami Auvinen, Dietmar Geiger, Rainer Hedrich, Hannes Kollist, Jaakko Sakari Kangasjärvi

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Guard cells control the aperture of stomatal pores to balance photosynthetic carbon dioxide uptake with evaporative water loss. Stomatal closure is triggered by several stimuli that initiate complex signaling networks to govern the activity of ion channels. Activation of SLOW ANION CHANNEL1 (SLAC1) is central to the process of stomatal closure and requires the leucine-rich repeat receptor-like kinase (LRR-RLK) GUARD CELL HYDROGEN PEROXIDE-RESISTANT1 (GHR1), among other signaling components. Here, based on functional analysis of nine Arabidopsis thaliana ghr1 mutant alleles identified in two independent forward-genetic ozone-sensitivity screens, we found that GHR1 is required for stomatal responses to apoplastic reactive oxygen species, abscisic acid, high CO2 concentrations, and diurnal light/dark transitions. Furthermore, we show that the amino acid residues of GHR1 involved in ATP binding are not required for stomatal closure in Arabidopsis or the activation of SLAC1 anion currents in Xenopus laevis oocytes and present supporting in silico and in vitro evidence suggesting that GHR1 is an inactive pseudokinase. Biochemical analyses suggested that GHR1-mediated activation of SLAC1 occurs via interacting proteins and that CALCIUM-DEPENDENT PROTEIN KINASE3 interacts with GHR1. We propose that GHR1 acts in stomatal closure as a scaffolding component.

Original languageEnglish
JournalPlant Cell
Volume30
Issue number11
Pages (from-to)2813-2837
Number of pages25
ISSN1040-4651
DOIs
Publication statusPublished - Nov 2018
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 2C PROTEIN PHOSPHATASES
  • ABSCISIC-ACID
  • ANION CHANNEL SLAC1
  • ARABIDOPSIS
  • CELL-DEATH
  • HYDROGEN-PEROXIDE
  • KINASE BIK1
  • NADPH OXIDASE RBOHD
  • REDUCED AIR HUMIDITY
  • SIGNAL-TRANSDUCTION
  • 1182 Biochemistry, cell and molecular biology
  • 1183 Plant biology, microbiology, virology

Cite this

Sierla, M. E., Hõrak, H., Overmyer, K. L., Waszczak, C. M., Yarmolinsky, D., Maierhofer, T., Vainonen, J., Denessiouk, K., Salojärvi, J. T., Laanemets, K., Tõldsepp, K., Vahisalu, T., Gauthier, A. G. B., Puukko, T., Paulin, L., Auvinen, P. O. V., Geiger, D., Hedrich, R., Kollist, H., & Kangasjärvi, J. S. (2018). The receptor-like pseudokinase GHR1 is required for stomatal closure. Plant Cell, 30(11), 2813-2837. https://doi.org/10.1105/tpc.18.00441