Submitted to: Annual Reviews of Cell and Developmental Biology
Publication Type: Review article
Publication Acceptance Date: 6/16/2004
Publication Date: 11/1/2004
Citation: Hake, S.C., Smith, H.M., Holtan, H., Magnani, E., Mele, G., Ramirez, J. 2004. The Role of KNOX Genes in Plant Development. Annual Reviews of Cell and Developmental Biology, 20:125-151. Interpretive Summary: knox genes encode homeodomain-containing transcription factors that are required for meristem maintenance and proper patterning of organ initiation. In plants with simple leaves, knox genes are expressed exclusively in the meristem and stem, but in dissected leaves, they are also expressed in leaf primordia, suggesting that they may play a role in the diversity of leaf form. This hypothesis is supported by the intriguing phenotypes found in gain-of-function mutations where knox gene misexpression affects leaf and petal shape. Similar phenotypes are also found in recessive mutations of genes that function to negatively regulate knox genes. KNOX proteins function as heterodimers with other homeodomains in the TALE superclass. The gibberellin and lignin biosynthetic pathways are known to be negatively regulated by KNOX proteins, which results in indeterminate cell fates.
Technical Abstract: The role of KNOX genes in plant development is covered. Topics include domains of expression, loss and gain of function of phenotypes and protein interactions.