title: LLM-Domain B-GATA Transcription Factors Promote Stomatal Development Downstream of Light Signaling Pathways in Arabidopsis thaliana Hypocotyls.
abstract: Stomata are pores that regulate the gas and water exchange between the environment and aboveground plant tissues, including hypocotyls, leaves, and stems. Here, we show that mutants of Arabidopsis thaliana LLM-domain B-GATA genes are defective in stomata formation in hypocotyls. Conversely, stomata formation is strongly promoted by overexpression of various LLM-domain B-class GATA genes, most strikingly in hypocotyls but also in cotyledons. Genetic analyses indicate that these B-GATAs act upstream of the stomata formation regulators SPEECHLESS(SPCH), MUTE, and SCREAM/SCREAM2 and downstream or independent of the patterning regulators TOO MANY MOUTHS and STOMATAL DENSITY AND DISTRIBUTION1 The effects of the GATAs on stomata formation are light dependent but can be induced in dark-grown seedlings by red, far-red, or blue light treatments. PHYTOCHROME INTERACTING FACTOR(PIF) mutants form stomata in the dark, and in this genetic background, GATA expression is sufficient to induce stomata formation in the dark. Since the expression of the LLM-domain B-GATAs GNC(GATA, NITRATE-INDUCIBLE, CARBON METABOLISM-INVOLVED) and GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR1 as well as that of SPCH is red light induced but the induction of SPCH is compromised in a GATA gene mutant background, we hypothesize that PIF- and light-regulated stomata formation in hypocotyls is critically dependent on LLM-domain B-GATA genes.
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Carina
authors.identifier: http://orcid.org/0000-0002-4438-606X
authors.initials: C
authors.lastname: Klermund
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Quirin L
authors.initials: QL
authors.lastname: Ranftl
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Diener
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Bastakis
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Richter
authors.affiliation: Plant Systems Biology, Technische Universität München, 85354 Freising, Germany claus.schwechheimer@wzw.tum.de.
authors.forename: Claus
authors.identifier: http://orcid.org/0000-0003-0269-2330
authors.initials: C
authors.lastname: Schwechheimer
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003583:Cytokinins / Q000378:metabolism*; D003624:Darkness; D050980:GATA Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018546:Hypocotyl / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D008027:Light; D055537:Light Signal Transduction; D009154:Mutation; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018547:Plant Stems / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D054046:Plant Stomata / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D030821:Plants, Genetically Modified; D000072417:Protein Domains; D036226:Seedlings / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D050980:GATA Transcription Factors; D010937:Plant Growth Regulators