A KNOX family TALE

Knotted1 defined the first homeobox gene family to be isolated in plants and was identified from dominant maize mutants that produced ‘knots’ of mis-specified tissue on the leaf. The Knotted1-like homeobox (KNOX) gene family expanded last year to include members lacking the defining homeobox with exciting implications for KNOX gene regulation and function. Recent evidence for direct KNOX regulation by myb-related ARP proteins and epigenetic silencing by polycomb repressive complexes have also shed light on the mechanisms defining KNOX gene expression.