title: Comprehensive transcriptome analysis unravels the existence of crucial genes regulating primary metabolism during adventitious root formation in Petunia hybrida.
abstract: To identify specific genes determining the initiation and formation of adventitious roots (AR), a microarray-based transcriptome analysis in the stem base of the cuttings of Petunia hybrida (line W115) was conducted. A microarray carrying 24,816 unique, non-redundant annotated sequences was hybridized to probes derived from different stages of AR formation. After exclusion of wound-responsive and root-regulated genes, 1,354 of them were identified which were significantly and specifically induced during various phases of AR formation. Based on a recent physiological model distinguishing three metabolic phases in AR formation, the present paper focuses on the response of genes related to particular metabolic pathways. Key genes involved in primary carbohydrate metabolism such as those mediating apoplastic sucrose unloading were induced at the early sink establishment phase of AR formation. Transcriptome changes also pointed to a possible role of trehalose metabolism and SnRK1 (sucrose non-fermenting 1- related protein kinase) in sugar sensing during this early step of AR formation. Symplastic sucrose unloading and nucleotide biosynthesis were the major processes induced during the later recovery and maintenance phases. Moreover, transcripts involved in peroxisomal beta-oxidation were up-regulated during different phases of AR formation. In addition to metabolic pathways, the analysis revealed the activation of cell division at the two later phases and in particular the induction of G1-specific genes in the maintenance phase. Furthermore, results point towards a specific demand for certain mineral nutrients starting in the recovery phase.
authors: Institute of Biological Chemistry, Washington State University, Pullman, Washington, United States of America.
authors: Amirhossein
authors: A
authors: Ahkami
authors: Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
authors: Uwe
authors: U
authors: Scholz
authors: The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom.
authors: Burkhard
authors: B
authors: Steuernagel
authors: SYNMIKRO, Philipps-Universität, Marburg, Germany.
authors: Marc
authors: M
authors: Strickert
authors: Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Grossbeeren & Erfurt, Germany.
authors: Klaus-Thomas
authors: KT
authors: Haensch
authors: Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Grossbeeren & Erfurt, Germany.
authors: Uwe
authors: U
authors: Druege
authors: Department of Biology, University of Fribourg, Fribourg, Switzerland.
authors: Didier
authors: D
authors: Reinhardt
authors: Department of Biology, University of Fribourg, Fribourg, Switzerland.
authors: Eva
authors: E
authors: Nouri
authors: Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
authors: Nicolaus
authors: N
authors: von Wirén
authors: Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Grossbeeren & Erfurt, Germany.
authors: Philipp
authors: P
authors: Franken
authors: Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
authors: Mohammad-Reza
authors: MR
authors: Hajirezaei
mesh_terms: D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D053858:Metabolic Networks and Pathways / Q000235:genetics; D058977:Molecular Sequence Annotation; D020411:Oligonucleotide Array Sequence Analysis; D032306:Petunia / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D059467:Transcriptome