title: Acetohydroxyacid synthase activity and transcripts profiling reveal tissue-specific regulation of ahas genes in sunflower.
abstract: Acetohydroxyacid synthase (AHAS) is the target site of several herbicides and catalyses the first step in the biosynthesis of branched chain amino acid. Three genes coding for AHAS catalytic subunit (ahas1, ahas2 and ahas3) have been reported for sunflower. The aim of this work was to study the expression pattern of ahas genes family and AHAS activity in sunflower (Helianthus annuus L.). Different organs (leaves, hypocotyls, roots, flowers and embryos) were evaluated at several developmental stages. The transcriptional profile was studied through RT-qPCR. The highest expression for ahas1 was shown in leaves, where all the induced and natural gene mutations conferring herbicide resistance were found. The maximal expression of ahas2 and ahas3 occurred in immature flowers and embryos. The highest AHAS activity was found in leaves and immature embryos. Correlation analysis among ahas gene expression and AHAS activity was discussed. Our results show that differences in ahas genes expression are tissue-specific and temporally regulated. Moreover, the conservation of multiple AHAS isoforms in sunflower seems to result from different expression requirements controlled by tissue-specific regulatory mechanisms at different developmental stages.
authors.affiliation: Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina; CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina. Electronic address: anaochogavia@conicet.gov.ar.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Ochogavía
authors.affiliation: Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina; CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Breccia
authors.affiliation: Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina; CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vega
authors.affiliation: Laboratorio de Biología Molecular, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina; CONICET, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina.
authors.forename: Silvina A
authors.initials: SA
authors.lastname: Felitti
authors.affiliation: Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina; CIUNR, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina.
authors.forename: Liliana A
authors.initials: LA
authors.lastname: Picardi
authors.affiliation: Cátedra de Genética, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, CC 14, S2125ZAA Zavalla, Argentina.
authors.forename: Graciela
authors.initials: G
authors.lastname: Nestares
mesh_terms: D000095:Acetolactate Synthase / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006368:Helianthus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D053209:Herbicide Resistance / Q000235:genetics; D006877:Hydroxamic Acids / Q000378:metabolism*; D007527:Isoenzymes; D009154:Mutation; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018514:Plant Structures / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D006877:Hydroxamic Acids; D007527:Isoenzymes; D010940:Plant Proteins; C006358:acetohydroxamic acid; D000095:Acetolactate Synthase
keywords: AHAS activity; Acetohydroxyacid synthase; Gene expression; Helianthus annuus L.; Sunflower; ahas genes