KNOX genes were initially found as shoot meristem regulators in angiosperms. Recent studies in diverse plant lineages however, have revealed the divergence of KNOX gene function during the evolution of diploid body plans. Using genomic approaches, class I KNOX transcription factors have been shown to regulate multiple hormone pathways including auxin and brassinosteroid as well as many transcription factors that play important roles in plant development. Class I KNOX proteins appear to be activators, whereas class II proteins act as repressors in transcriptional regulation of their target genes.
Published by Elsevier Ltd.