phytochrome B Is required for light-mediated systemic control of stomatal development.
Stomata are pores found on the surfaces of leaves, and they regulate gas exchange between the plant and the environment [1]. Stomatal development is highly plastic and is influenced by environmental signals [2]. Light stimulates stomatal development, and this response is mediated by plant photoreceptors [3-5], with the red-light photoreceptor phytochrome B (phyB) having a dominant role in white light [3]. Light also regulates stomatal development systemically, with the irradiance perceived by mature leaves modulating stomatal development in young leaves [6, 7]. Here, we show that phyB is required for this systemic response. Using a combination of tissue-specific expression and an inducible expression system in the loss-of-function phyB-9 mutant [8], we show that phyB expression in the stomatal lineage, mesophyll, and phloem is sufficient to restore wild-type stomatal development. Induction of PHYB in mature leaves also rescues stomatal development in young untreated leaves, whereas phyB mutants are defective in the systemic regulation of stomatal development. Our data show that phyB acts systemically to regulate cell fate decisions in the leaf epidermis.
Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK. Electronic address: s.casson@sheffield.ac.uk.
Stuart A
SA
Casson
School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
Alistair M
AM
Hetherington
D016960:Agrobacterium tumefaciens / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000528:radiation effects; D008027:Light; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D058503:Mesophyll Cells / Q000378:metabolism / Q000528:radiation effects; D009928:Organ Specificity; D052585:Phloem / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D051939:Phytochrome B / Q000235:genetics* / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D054046:Plant Stomata / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D008164:Luminescent Proteins; D011994:Recombinant Proteins; C054562:yellow fluorescent protein, Bacteria; D051939:Phytochrome B