Theknotted1-like homeobox geneBREVIPEDICELLUSregulates cell differentiation by modulating metabolic pathways

Abstract
Members of theKNOXgene family have important roles in plant meristems by regulating cell division and differentiation.BREVIPEDICELLUS(BP), one of sevenKNOXgenes inArabidopsis, has a primary role in internode patterning. We carried out a comparison of RNA expression profiles between wild-type seedlings andbpmutants at a developmental stage prior to a visible phenotypic difference. Transcript differences were found for a number of genes in cell wall biosynthesis, especially genes in the lignin pathway. The regulation of lignin biosynthesis byBPwas demonstrated by observing increased lignin deposition inbpmutants following bolting, decreased lignification in plants overexpressingBP, and aberrant lignin deposition in discrete regions of thebpstem. Furthermore, we showed that BP binds promoters of some genes in the lignin pathway. Our results provide a metabolic fingerprint forBPand identify the lignin pathway as one of the coordinate processes thatBPregulates.