title: A higher sink competitiveness of the rooting zone and invertases are involved in dark stimulation of adventitious root formation in Petunia hybrida cuttings.
abstract: The contribution of carbon assimilation and allocation and of invertases to the stimulation of adventitious root formation in response to a dark pre-exposure of petunia cuttings was investigated, considering the rooting zone (stem base) and the shoot apex as competing sinks. Dark exposure had no effect on photosynthesis and dark respiration during the subsequent light period, but promoted dry matter partitioning to the roots. Under darkness, higher activities of cytosolic and vacuolar invertases were maintained in both tissues when compared to cuttings under light. This was partially associated with higher RNA levels of respective genes. However, activity of cell wall invertases and transcript levels of one cell wall invertase isogene increased specifically in the stem base during the first two days after cutting excision under both light and darkness. During five days after excision, RNA accumulation of four invertase genes indicated preferential expression in the stem base compared to the apex. Darkness shifted the balance of expression of one cytosolic and two vacuolar invertase genes towards the stem base. The results indicate that dark exposure before planting enhances the carbon sink competitiveness of the rooting zone and that expression and activity of invertases contribute to the shift in carbon allocation.
authors.affiliation: Leibniz Institute of Vegetable and Ornamental Crops, Kuehnhauser Strasse 101, D-99090 Erfurt, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Klopotek
authors.affiliation: Leibniz Institute of Vegetable and Ornamental Crops, Kuehnhauser Strasse 101, D-99090 Erfurt, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Franken
authors.affiliation: Leibniz Institute of Vegetable and Ornamental Crops, Theodor-Echtermeyer-Weg 1, D-14979 Grossbeeren, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Klaering
authors.affiliation: Leibniz Institute of Vegetable and Ornamental Crops, Theodor-Echtermeyer-Weg 1, D-14979 Grossbeeren, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Fischer
authors.affiliation: Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Hause
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstrasse 3, D-06466 Gatersleben, Germany.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Hajirezaei
authors.affiliation: Leibniz Institute of Vegetable and Ornamental Crops, Kuehnhauser Strasse 101, D-99090 Erfurt, Germany. Electronic address: druege@erfurt.igzev.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Druege
mesh_terms: D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D057965:Carbon Sequestration; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D032306:Petunia / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D043324:beta-Fructofuranosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D002245:Carbon Dioxide; D002244:Carbon; D043324:beta-Fructofuranosidase
keywords: Carbon allocation; Enzyme activity; Gene expression; Photosynthesis; Root development; Storage