Journal Article

A Genome-Wide Regulatory Framework Identifies Maize Pericarp Color1 Controlled Genes

Morohashi, Kengo, Yilmaz, Alper, Pellegrinet, Silvina, Ferreyra, Lorena Falcone, Casas, María Isabel, Casati, Paula, Pourcel, Lucille, Rodriguez, Eduardo, Mejía-Guerra, María Katherine, Feller, Antje, Carvalho, Bruna, Emiliani, Julia, McMullen, Michael, Grotewold, Erich

2012

Overview

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.

• Publisher: American Society of Plant Biologists
• Subject: Alleles / Base Sequence / Biosynthesis / chromatin / Cluster Analysis / Corn / Datasets / Flavanones - metabolism / Flavones / Flavonoids / Flavonoids - analysis / Flavonoids - genetics / Flavonoids - metabolism / gene expression / Gene Expression Regulation, Plant - genetics / Gene Library / Gene Regulatory Networks - genetics / Genes / Genome, Plant - genetics / Genomes / High-Throughput Nucleotide Sequencing / Pericarp / Phenotype / Plant cells / Plant Leaves - chemistry / Plant Leaves - genetics / Plant Leaves - metabolism / Plant Proteins - genetics / Plant Proteins - metabolism / precipitin tests / Propanols - metabolism / Seeds - chemistry / Seeds - genetics / Seeds - metabolism / Sequence Analysis, DNA / Sequence Analysis, RNA / silk / Transcription factors / Transcription Factors - genetics / Transcription Factors - metabolism / Transcriptional Activation / Zea mays - chemistry / Zea mays - genetics / Zea mays - metabolism