title: Variations in the mycorrhization characteristics in roots of wild-type and ABA-deficient tomato are accompanied by specific transcriptomic alterations.
abstract: Abscissic acid (ABA) determines mycorrhiza functionality and arbuscule development. In this study, we performed transcriptome analysis in response to different mycorrhization status according to the ABA content in the root to identify genes that may play a role in arbuscule functionality. Affymetrix Tomato GeneChip (approximately 10,000 probes) allowed us to detect and compare the transcriptional root profiling of tomato (Solanum lycopersicum) wild-type and ABA-deficient sitiens plants colonized by Glomus intraradices. A number of identified genes in tomato belong to a category of genes already described as "mycorrhizal core-set" in other host plants. The impairment in arbuscular mycorrhiza (AM) formation in ABA-deficient mutants was associated with upregulation of genes related to defense and cell wall modification, whereas functional mycorrhization in wild-type plants was associated with activation of genes related to isoprenoid metabolism. The oxylipin pathway was activated in tomato mycorrhizal roots at late stages of interaction, and was related to the control of fungal spread in roots, not with the establishment of the symbiosis. Induction of selected genes, representing a range of biological functions and representative of the three sets of genes specifically upregulated in the different plant phenotype, was confirmed by quantitative reverse-transcription polymerase chain reaction, and their response to phythohormone treatment was tested, showing that ethylene and jasmonic acid are key regulators of gene expression during AM development. Comparative analysis of mycorrhiza upregulated functional categories revealed significant changes in gene expression associated with the different mycorrhization status according to the ABA content in the roots.
authors.affiliation: Departmento de Microbiología del sueloy sistemas simbióticos, Estación Experimental del Zaidín, Spain. josemanuel.garcia@eez.csic.es
authors.forename: José Manuel García
authors.initials: JM
authors.lastname: Garrido
authors.forename: Rafael Jorge León
authors.initials: RJ
authors.lastname: Morcillo
authors.forename: José Angel Martín
authors.initials: JA
authors.lastname: Rodríguez
authors.forename: Juan Antonio Ocampo
authors.initials: JA
authors.lastname: Bote
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D002473:Cell Wall / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D055137:Glomeromycota / Q000187:drug effects / Q000502:physiology; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics* / Q000276:immunology / Q000382:microbiology*; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D038821:Mycorrhizae / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D013729:Terpenes / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D054883:Oxylipins; D010937:Plant Growth Regulators; D013729:Terpenes; D000040:Abscisic Acid