title: Metabolite profiling of Ricinus communis germination at different temperatures provides new insights into thermo-mediated requirements for successful seedling establishment.
abstract: Ricinus communis seeds germinate to a high percentage and faster at 35 °C than at lower temperatures, but with compromised seedling establishment. However, seedlings are able to cope with high temperatures at later stages of seedling establishment if germination occurred at lower temperatures. Our objective was to assess the biochemical and molecular requirements of R. communis germination for successful seedling establishment at varying temperatures. For that, we performed metabolite profiling (GC-TOF-MS) and measured transcript levels of key genes involved in several energy-generating pathways, such as storage oil mobilization, β-oxidation and gluconeogenesis of seeds germinated at three different temperatures. We identified a thermo-sensitive window during seed germination in which high temperatures compromise seedling development, most likely by down-regulating some energy-generating pathways. Overexpression of malate synthase (MLS) and glycerol kinase (GK) genes resulted in higher starch levels in Nicotiana benthamiana leaves, which highlights the importance of these genes in energy-generating pathways for seedling establishment. Additionally, we showed that GABA, which is a stress-responsive metabolite, accumulated in response to the water content of the seeds during the initial phase of imbibition. Herewith, we provide new insights into the molecular requirements for vigorous seedling growth of R. communis under different environmental conditions.
authors.affiliation: Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands; Laboratório de Bioquímica, Biotecnologia e Bioprodutos, Departmento de Biofunção, Universidade Federal da Bahia, Reitor Miguel Calmon s/n, 40160-100 Salvador, Brazil. Electronic address: paulodc3@gmail.com.
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Ribeiro
authors.affiliation: Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Leo A J
authors.initials: LA
authors.lastname: Willems
authors.affiliation: Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Marie-Chantal
authors.initials: MC
authors.lastname: Mutimawurugo
authors.affiliation: Laboratório de Bioquímica, Biotecnologia e Bioprodutos, Departmento de Biofunção, Universidade Federal da Bahia, Reitor Miguel Calmon s/n, 40160-100 Salvador, Brazil.
authors.forename: Luzimar G
authors.initials: LG
authors.lastname: Fernandez
authors.affiliation: Laboratório de Bioquímica, Biotecnologia e Bioprodutos, Departmento de Biofunção, Universidade Federal da Bahia, Reitor Miguel Calmon s/n, 40160-100 Salvador, Brazil.
authors.forename: Renato D
authors.initials: RD
authors.lastname: de Castro
authors.affiliation: Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands. Electronic address: wilco.ligterink@wur.nl.
authors.forename: Wilco
authors.initials: W
authors.lastname: Ligterink
authors.affiliation: Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
authors.forename: Henk W M
authors.initials: HW
authors.lastname: Hilhorst
mesh_terms: D018525:Germination; D006358:Hot Temperature; D012278:Ricinus / Q000254:growth & development* / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000254:growth & development / Q000378:metabolism
keywords: Carbon-nitrogen balance; GABA; Gluconeogenesis; Glyoxylate cycle; Seedling establishment; Stress responsive metabolites