title: The Arabidopsis alkaline ceramidase TOD1 is a key turgor pressure regulator in plant cells.
abstract: Turgor pressure plays pivotal roles in the growth and movement of walled cells that make up plants and fungi. However, the molecular mechanisms regulating turgor pressure and the coordination between turgor pressure and cell wall remodelling for cell growth remain poorly understood. Here, we report the characterization of Arabidopsis TurgOr regulation Defect 1 (TOD1), which is preferentially expressed in pollen tubes and silique guard cells. We demonstrate that TOD1 is a Golgi-localized alkaline ceramidase. tod1 mutant pollen tubes have higher turgor than wild type and show growth retardation both in pistils and in agarose medium. In addition, tod1 guard cells are insensitive to abscisic acid (ABA)-induced stomatal closure, whereas sphingosine-1-phosphate, a putative downstream component of ABA signalling and product of alkaline ceramidases, promotes closure in both wild type and tod1. Our data suggest that TOD1 acts in turgor pressure regulation in both guard cells and pollen tubes.
authors.affiliation: 1] State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Dong-Qiao
authors.initials: DQ
authors.lastname: Shi
authors.affiliation: 1] State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Zuo-Shun
authors.initials: ZS
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: 1] State Key Laboratory of Molecular Developmental Biology and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200433, China.
authors.forename: Wei-Cai
authors.initials: WC
authors.lastname: Yang
mesh_terms: D055574:Alkaline Ceramidase / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D008246:Lysophospholipids / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism; D053205:Pollen Tube / Q000201:enzymology / Q000378:metabolism; D015398:Signal Transduction; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D055574:Alkaline Ceramidase; D013110:Sphingosine