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United States Department of Agriculture

Agricultural Research Service

Title: Loss of Function Mutations in the Maize Homeobox Gene, Knotted1, Are Defective in Shoot Meristems

item Hake, Sarah
item Kerstetter, Randall - U.C. BERKELEY
item Smith, Laurie - UNIV. NORTH CAROLINA

Submitted to: Development Supplement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 10, 1997
Publication Date: N/A

Interpretive Summary: Maize plants that are missing a functional knotted1 gene have reduced tassel branching and female sterility. The results suggest that knotted1 plays a role in maintaining the meristem.

Technical Abstract: The product of the maize homeobox gene, knotted1 (kn1), localizes to the nuclei of cells in shoot meristems, but is absent from portions of the meristem where leaf primordia or floral organs initiate. Recessive mutant alleles of kn1 were obtained by screening for loss of the dominant leaf phenotype in maize. Mutant kn1 alleles carrying nonsense, splicing, and frame shift mutations cause severe inflorescence and floral defects. Mutan tassels produce fewer branches and spikelets. Ears are often absent, and when present, are small with few spikelets. In addition, extra carpels form in female florets and ovule tissue proliferates abnormally. Less frequently, extra leaves form in the axils of vegetative leaves. These mutations reveal a role for kn1 in meristem maintenance, particularly as it affects branching and lateral organ formation.

Last Modified: 4/19/2015
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