title: MBF1s regulate ABA-dependent germination of Arabidopsis seeds.
abstract: Transcriptional co-activators of the multiprotein bridging factor 1 (MBF1) controls gene expression by connecting transcription factors and the basal transcription machinery. In Arabidopsis thaliana functions of MBF1 genes have been related to stress tolerance and developmental alterations. Endogenous ABA plays a major role in the regulation of Arabidopsis seed dormancy and germination. Seed dormancy and ABA sensitivity are enhanced in ethylene insensitive mutants suggesting that ethylene signal transduction pathway is necessary to fully develop ABA-dependent germination. In this report we showed that a triple knock-down mutant for Arabidopsis MBF1 genes (abc-) has enhanced seed dormancy and displays hypersensitivity to exogenous ABA. In addition, higher ABA contents were detected in abc- seeds after imbibition. These evidences suggest a negative role of MBF1s genes in ABA-dependent inhibition of germination. The participation of MBF1s in ethylene signal transduction pathway is also discussed.
authors.affiliation: Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
authors.forename: María Florencia
authors.initials: MF
authors.lastname: Di Mauro
authors.forename: María José
authors.initials: MJ
authors.lastname: Iglesias
authors.forename: Débora Pamela
authors.initials: DP
authors.lastname: Arce
authors.forename: Estela Marta
authors.initials: EM
authors.lastname: Valle
authors.forename: Roberto Benech
authors.initials: RB
authors.lastname: Arnold
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tsuda
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Claudia Anahí
authors.initials: CA
authors.lastname: Casalongué
authors.forename: Andrea Verónica
authors.initials: AV
authors.lastname: Godoy
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination / Q000187:drug effects / Q000235:genetics*; D009154:Mutation; D057445:Plant Dormancy / Q000187:drug effects / Q000235:genetics; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; C491466:MBF1 protein, Arabidopsis; D010937:Plant Growth Regulators; D015534:Trans-Activators; D000040:Abscisic Acid; C036216:ethylene