title: The trehalose pathway in maize: conservation and gene regulation in response to the diurnal cycle and extended darkness.
abstract: Energy resources in plants are managed in continuously changing environments, such as changes occurring during the day/night cycle. Shading is an environmental disruption that decreases photosynthesis, compromises energy status, and impacts on crop productivity. The trehalose pathway plays a central but not well-defined role in maintaining energy balance. Here, we characterized the maize trehalose pathway genes and deciphered the impacts of the diurnal cycle and disruption of the day/night cycle on trehalose pathway gene expression and sugar metabolism. The maize genome encodes 14 trehalose-6-phosphate synthase (TPS) genes, 11 trehalose-6-phosphate phosphatase (TPP) genes, and one trehalase gene. Transcript abundance of most of these genes was impacted by the day/night cycle and extended dark stress, as were sucrose, hexose sugars, starch, and trehalose-6-phosphate (T6P) levels. After extended darkness, T6P levels inversely followed class II TPS and sucrose non-fermenting-related protein kinase 1 (SnRK1) target gene expression. Most significantly, T6P no longer tracked sucrose levels after extended darkness. These results showed: (i) conservation of the trehalose pathway in maize; (ii) that sucrose, hexose, starch, T6P, and TPS/TPP transcripts respond to the diurnal cycle; and(iii) that extended darkness disrupts the correlation between T6P and sucrose/hexose pools and affects SnRK1 target gene expression. A model for the role of the trehalose pathway in sensing of sucrose and energy status in maize seedlings is proposed.
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA.
authors.forename: Clémence
authors.initials: C
authors.lastname: Henry
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA.
authors.forename: Samuel W
authors.initials: SW
authors.lastname: Bledsoe
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Siekman
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA.
authors.forename: Alec
authors.initials: A
authors.lastname: Kollman
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Waters
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA Max Planck Institut für Molekulare Pflanzenphysiologie, Potsdam (OT) Golm, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Feil
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA Max Planck Institut für Molekulare Pflanzenphysiologie, Potsdam (OT) Golm, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Stitt
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE 68583-0915, USA mlagrimini2@unl.edu.
authors.forename: L Mark
authors.initials: LM
authors.lastname: Lagrimini
mesh_terms: D050260:Carbohydrate Metabolism; D002940:Circadian Rhythm; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases; D036226:Seedlings / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013403:Sugar Phosphates / Q000378:metabolism; D014199:Trehalose / Q000031:analogs & derivatives / Q000378:metabolism; D003313:Zea mays / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects
chemical_list: D010940:Plant Proteins; D013403:Sugar Phosphates; C082722:trehalose-6-phosphate; D013395:Sucrose; D013213:Starch; D014199:Trehalose; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; C023178:trehalose-phosphatase; D010744:Phosphoric Monoester Hydrolases
keywords: Maize; diurnal cycle,; quantitative RT-PCR.; shade stress,; trehalose gene family; trehalose-6-phosphate