title: Phenotypic plasticity to altered apical bud temperature in Cucumis sativus: more leaves-smaller leaves and vice versa.
abstract: Many studies investigated temperature effects on leaf initiation and expansion by relating these processes to air temperature or the temperature of a specific organ (e.g. leaf temperature). In reality plant temperature is hardly ever equal to air temperature or spatially uniform. Apical bud temperature (Tbud), for example, may greatly differ from the temperature of the rest of the plant (Tplant) dependent on the environment. Recent research in Cucumis sativus showed that Tbudinfluences leaf initiation independent of Tplant. These findings trigger the question if such spatial temperature differences also influence leaf expansion and plant phenotype. In a 28 day study, we maintained temperature differences between Tbudand Tplantranging from -7 to +8 °C using a custom-made bud temperature control system. Leaf expansion did not only depend on leaf temperature but also on the difference between bud and leaf temperature. Differences between Tbudand Tplantconsiderably influenced vertical leaf area distribution over the shoot: increasing Tbudbeyond Tplantresulted in more and smaller leaves, while decreasing Tbudbelow Tplantresulted in less and larger leaves. The trade-off between leaf number and leaf area resulted in phenotypic alterations that cannot be predicted, for example, by crop models, when assuming plant temperature uniformity.
authors.affiliation: Horticulture and Product Physiology, Wageningen University, PO Box 16, 6700AA, Wageningen, The Netherlands.|Wageningen UR Greenhouse Horticulture, PO Box 644, 6700AP, Wageningen, The Netherlands.
authors.forename: Andreas
authors.identifier: 0000-0001-7585-3313
authors.initials: A
authors.lastname: Savvides
authors.affiliation: Horticulture and Product Physiology, Wageningen University, PO Box 16, 6700AA, Wageningen, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van Ieperen
authors.affiliation: Wageningen UR Greenhouse Horticulture, PO Box 644, 6700AP, Wageningen, The Netherlands.
authors.forename: Janneke A
authors.initials: JA
authors.lastname: Dieleman
authors.affiliation: Horticulture and Product Physiology, Wageningen University, PO Box 16, 6700AA, Wageningen, The Netherlands.
authors.forename: Leo F M
authors.initials: LF
authors.lastname: Marcelis
mesh_terms: D018533:Biomass; D018553:Cucumis sativus / Q000254:growth & development / Q000502:physiology*; D010641:Phenotype; D063245:Plant Development; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000502:physiology*; D013696:Temperature
keywords: leaf expansion; phytomer; shoot apical meristem; temperature differences; thermal time