Poster: Mineral nutrition
Abs #
194: Contribution of cyanide assimilation to one nitrogen metabolism in plants
Cyanide is used extensively in industry and is a common environmental contaminant. Cyanide is also a ubiquitous compound in plant metabolism where it is used for defense, as a nitrogen source, and is produced in a 1:1 basis with ethylene during senescence and stress. Recent data has suggested that in willow (Salix eriocephala var. Michaux), cyanide is preferentially assimilated over nitrate and ammonia, even when the latter two were present at higher concentrations. Asparagine and glutamate were the primary amino acids into which cyanogenic nitrogen was incorporated (as indicated by 15N abundance), which suggest involvement of the cyanoalanine pathway in assimilation. In addition, the distribution of aromatic amino acids shifted during cyanide exposure, with phenylalanine detected primarily in roots in untreated plants and in leaves of cyanide-treated plants. These results were observed in the absence of any cyanide-induced plant stress or toxicity. These data raise questions about the fundamental role of cyanide in plant nitrogen metabolism, which are currently under investigation. Specifically, we are working to demonstrate the relationship between cyanide assimilation and activity of cyanoalanine synthase-like enzymes in plants.
