title: Fruit specific variability in capsaicinoid accumulation and transcription of structural and regulatory genes in Capsicum fruit.
abstract: Accumulation of capsaicinoids in the placental tissue of ripening chile (Capsicum spp.) fruit follows the coordinated expression of multiple biosynthetic enzymes producing the substrates for capsaicin synthase. Transcription factors are likely agents to regulate expression of these biosynthetic genes. Placental RNAs from habanero fruit (Capsicum chinense) were screened for expression of candidate transcription factors; with two candidate genes identified, both in the ERF family of transcription factors. Characterization of these transcription factors, Erf and Jerf, in nine chile cultivars with distinct capsaicinoid contents demonstrated a correlation of expression with pungency. Amino acid variants were observed in both ERF and JERF from different chile cultivars; none of these changes involved the DNA binding domains. Little to no transcription of Erf was detected in non-pungent Capsium annuum or C. chinense mutants. This correlation was characterized at an individual fruit level in a set of jalapeño (C. annuum) lines again with distinct and variable capsaicinoid contents. Both Erf and Jerf are expressed early in fruit development, 16-20 days post-anthesis, at times prior to the accumulation of capsaicinoids in the placental tissues. These data support the hypothesis that these two members of the complex ERF family participate in regulation of the pungency phenotype in chile.
authors.affiliation: Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Neda
authors.initials: N
authors.lastname: Keyhaninejad
authors.affiliation: Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Curry
authors.affiliation: Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Joslynn
authors.initials: J
authors.lastname: Romero
authors.affiliation: Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003, USA. Electronic address: moconnel@nmsu.edu.
authors.forename: Mary A
authors.initials: MA
authors.lastname: O'Connell
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics; D002211:Capsaicin / Q000378:metabolism*; D002212:Capsicum / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010641:Phenotype; D063245:Plant Development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D012313:RNA / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000596:Amino Acids; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D014157:Transcription Factors; C093680:ethylene-responsive element binding protein; D012313:RNA; D002211:Capsaicin
keywords: Capsaicinoids; Capsicum; Fruit pungency; Transcription factors