title: Early steps of adventitious rooting: morphology, hormonal profiling and carbohydrate turnover in carnation stem cuttings.
abstract: The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. A detailed analysis of the morphological changes occurring in the basal region of cultivated carnation cuttings during the early stages of adventitious rooting was carried out and the physiological modifications induced by exogenous auxin application were studied. To this end, the endogenous concentrations of five major classes of plant hormones [auxin, cytokinin (CK), abscisic acid, salicylic acid (SA) and jasmonic acid] and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid were analyzed at the base of stem cuttings and at different stages of adventitious root formation. We found that the stimulus triggering the initiation of adventitious root formation occurred during the first hours after their excision from the donor plant, due to the breakdown of the vascular continuum that induces auxin accumulation near the wounding. Although this stimulus was independent of exogenously applied auxin, it was observed that the auxin treatment accelerated cell division in the cambium and increased the sucrolytic activities at the base of the stem, both of which contributed to the establishment of the new root primordia at the stem base. Further, several genes involved in auxin transport were upregulated in the stem base either with or without auxin application, while endogenous CK and SA concentrations were specially affected by exogenous auxin application. Taken together our results indicate significant crosstalk between auxin levels, stress hormone homeostasis and sugar availability in the base of the stem cuttings in carnation during the initial steps of adventitious rooting.
authors.affiliation: Departamento de Biología Vegetal (Fisiología Vegetal), Universidad de Murcia, 30100, Murcia, Spain.
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Agulló-Antón
authors.forename: Almudena
authors.initials: A
authors.lastname: Ferrández-Ayela
authors.forename: Nieves
authors.initials: N
authors.lastname: Fernández-García
authors.forename: Carlos
authors.initials: C
authors.lastname: Nicolás
authors.forename: Alfonso
authors.initials: A
authors.lastname: Albacete
authors.forename: Francisco
authors.initials: F
authors.lastname: Pérez-Alfocea
authors.forename: José
authors.initials: J
authors.lastname: Sánchez-Bravo
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Pérez-Pérez
authors.forename: Manuel
authors.initials: M
authors.lastname: Acosta
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000598:Amino Acids, Cyclic / Q000378:metabolism; D050260:Carbohydrate Metabolism; D003583:Cytokinins / Q000378:metabolism; D029749:Dianthus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology; D007541:Isopentenyladenosine / Q000031:analogs & derivatives / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010937:Plant Growth Regulators / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012459:Salicylates / Q000378:metabolism; D046509:Tissue Culture Techniques
chemical_list: D000598:Amino Acids, Cyclic; D003583:Cytokinins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012459:Salicylates; C023863:1-aminocyclopropane-1-carboxylic acid; D000040:Abscisic Acid; D007541:Isopentenyladenosine; C009699:zeatin riboside