Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Gnarley1 Is a Dominant Mutation in the Knox4 Homeobox Gene Affecting Cell Shape and Identity

Authors
item Hake, Sarah
item Foster, T. - MASSEY UNIV, N. ZEALAND
item Yamaguchi, J. - UCB
item Wong, B. - UCB
item Veit, B. - MASSEY UNIV, N. ZEALAND

Submitted to: The Plant Cell
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 1999
Publication Date: July 1, 1999
Citation: Hake, S.C., Foster, T., Yamaguchi, J., Wong, B.C., Veit, B. 1999. Gnarley1 is a dominant mutation in the knox4 homeobox gene affecting cell shape and identity. The Plant Cell, 11:1239-1252.

Interpretive Summary: Maize leaves have a stereotypical pattern of cell types organized into discrete domains which are altered by mutations in knotted1 (kn1) and knox (for kn1-like homeobox) genes. Gnarley (Gn1) is a dominant maize mutant that exhibits many of the phenotypic characteristics of the kn1 family of mutants. We demonstrated that Gn1 is knox4 by correlating loss of the mutant phenotype with insertion of a Mutator transposon into knox4.

Technical Abstract: Maize leaves have a stereotypical pattern of cell types organized into discrete domains. These domains are altered by mutations in knotted1 (kn1) and knox (for kn1-like homeobox) genes. Gnarley (Gn1) is a dominant maize mutant that exhibits many of the phenotypic characteristics of the kn1 family of mutants. Gn1 is unique because it changes parameters of cell growth in the basal-most region of the leaf, the sheath, resulting in dramatically altered sheath morphology. The strongly expressive allele Gn1-R also gives rise to a floral phenotype in which ectopic carpels form. Introgression studies showed that the severity of the Gn1-conferred phenotype is strongly influenced by genetic background. Gn1 maps to knox4, and knox4 is ectopically expressed in plants with the Gn1-conferred phenotype. Immunolocalization experiments showed that the KNOX protein accumulates at the base of Gn1 leaves in a pattern that is spatially and temporally correlated with appearance of the mutant phenotype. We further demonstrate that Gn1 is knox4 by correlating loss of the mutant phenotype with insertion of a Mutator transposon into knox4.

Last Modified: 12/21/2014
Footer Content Back to Top of Page