title: A genome-wide regulatory framework identifies maize pericarp color1 controlled genes.
abstract: Pericarp Color1 (P1) encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize (Zea mays) silks and red phlobaphene pigments in pericarps and other floral tissues, which makes P1 an important visual marker. Using genome-wide expression analyses (RNA sequencing) in pericarps and silks of plants with contrasting P1 alleles combined with chromatin immunoprecipitation coupled with high-throughput sequencing, we show here that the regulatory functions of P1 are much broader than the activation of genes corresponding to enzymes in a branch of flavonoid biosynthesis. P1 modulates the expression of several thousand genes, and ∼1500 of them were identified as putative direct targets of P1. Among them, we identified F2H1, corresponding to a P450 enzyme that converts naringenin into 2-hydroxynaringenin, a key branch point in the P1-controlled pathway and the first step in the formation of insecticidal C-glycosyl flavones. Unexpectedly, the binding of P1 to gene regulatory regions can result in both gene activation and repression. Our results indicate that P1 is the major regulator for a set of genes involved in flavonoid biosynthesis and a minor modulator of the expression of a much larger gene set that includes genes involved in primary metabolism and production of other specialized compounds.
authors: Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
authors: Kengo
authors: K
authors: Morohashi
authors: María Isabel
authors: MI
authors: Casas
authors: Maria Lorena
authors: ML
authors: Falcone Ferreyra
authors: Lorena
authors: L
authors: Falcone Ferreyra
authors: María Katherine
authors: MK
authors: Mejía-Guerra
authors: Lucille
authors: L
authors: Pourcel
authors: Alper
authors: A
authors: Yilmaz
authors: Antje
authors: A
authors: Feller
authors: Bruna
authors: B
authors: Carvalho
authors: Julia
authors: J
authors: Emiliani
authors: Eduardo
authors: E
authors: Rodriguez
authors: Silvina
authors: S
authors: Pellegrinet
authors: Michael
authors: M
authors: McMullen
authors: Paula
authors: P
authors: Casati
authors: Erich
authors: E
authors: Grotewold
mesh_terms: D000483:Alleles; D001483:Base Sequence; D016000:Cluster Analysis; D044950:Flavanones / Q000378:metabolism; D005419:Flavonoids / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D015723:Gene Library; D053263:Gene Regulatory Networks / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D010641:Phenotype; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D020005:Propanols / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017423:Sequence Analysis, RNA; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation; D003313:Zea mays / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D044950:Flavanones; D005419:Flavonoids; D010940:Plant Proteins; D020005:Propanols; D014157:Transcription Factors; C439395:1-phenylpropanol; C091603:phlobaphene; C005273:naringenin