ARS | Publication request: Potential anthranilate modifying enzymes of maize mutant bf-1

Submitted to: American Society of Plant Biologists
Publication Type: Abstract
Publication Acceptance Date: July 1, 2008
Publication Date: July 1, 2008
Citation: Pinkerton, T.S., Dowd, P.F. 2008. Potential anthranilate modifying enzymes of maize mutant bf-1. American Society of Plant Biologists. p. 106.

Technical Abstract: Seedlings of maize mutant bf-1 exhibit blue fluorescence and a distinct grape odor due to an accumulation of methyl anthranilate and other anthranilate related compounds. The bf-1 also expresses a feedback insensitive anthranilate synthase. Previously, we identified a unique mutation in anthranilate synthase expressed in bf-1 seedlings. While transgenic expression of this mutation in maize did result in some fluorescence in transformant plants, it did not result in an odor phenotype like that seen in bf-1 plants. Blue fluorescent mutants of Arabidopsis have been shown to be dependent on a salicylic acid UDP-glucosyltransferase. Because of the lack of strong phenotype in transgenic maize plants, we are investigating potential anthranilate modifying enzymes in bf-1 maize. One salicylic acid UDP-glucosyltransferase and three potential salicylic acid carboxymethyltransferases were identified from maize genomic sequences. All four potential genes were cloned from genomic DNA and sequenced. RT-PCR was also run on cDNA generated from bf-1 seedling mRNA, and two of the carboxymethyltransferase sequences were detected. Characterization of the modifying enzyme gene sequences from bf-1 will be presented along with comparison to sequences from non-mutant maize lines and other plant species. Expression of the potential genes in bf-1 seedlings and in maize lines treated with a compound shown to induce hypersensitive response will also be presented. The identification and characterization of these genes could potentially add a scent/fluorescence marker when used in conjunction with a tryptophan resistant anthranilate synthase as a selectable marker. The accumulation of metabolites of anthranilate and salicylate could also influence hypersensitive response and resistance to insect pests.