A genomic clone containing the gl1-2 allele has been isolated and sequenced. The predicted amino acid sequence of the gl1-2 protein is identical to that of the GL1-Col allele up to position 201. At this point in the coding region of gl1-2 there is a deletion relative to the wild-type sequence that results in an in-frame stop codon at position 202. This deletion removes 27 amino acid residues, including a highly negatively charged region, from the predicted gl1-2 polypeptide. The loss of this negatively charged carboxy-terminal region from the gl1-2 product is most likely the cause of the partial loss of gene activity which results in a reduction in leaf trichome initiation.