The Nitrilase ZmNIT2 Converts Indole-3-Acetonitrile to Indole-3-Acetic Acid1
AUTOR(ES)
Park, Woong June
FONTE
The American Society for Plant Biologists
RESUMO
We isolated two nitrilase genes, ZmNIT1 and ZmNIT2, from maize (Zea mays) that share 75% sequence identity on the amino acid level. Despite the relatively high homology to Arabidopsis NIT4, ZmNIT2 shows no activity toward β-cyano-alanine, the substrate of Arabidopsis NIT4, but instead hydrolyzes indole-3-acetonitrile (IAN) to indole-3-acetic acid (IAA). ZmNIT2 converts IAN to IAA at least seven to 20 times more efficiently than AtNIT1/2/3. Quantitative real-time polymerase chain reaction revealed the gene expression of both nitrilases in maize kernels where high concentrations of IAA are synthesized tryptophan dependently. Nitrilase protein and endogenous nitrilase activity are present in maize kernels together with the substrate IAN. These results suggest a role for ZmNIT2 in auxin biosynthesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=219053Documentos Relacionados
- Uptake of Indole-3-acetic Acid and Indole-3-acetonitrile by Avena Coleoptile Sections 12
- Arabidopsis mutants resistant to the auxin effects of indole-3-acetonitrile are defective in the nitrilase encoded by the NIT1 gene.
- Occurrence of enzymes involved in biosynthesis of indole-3-acetic acid from indole-3-acetonitrile in plant-associated bacteria, Agrobacterium and Rhizobium.
- Nitrilase in biosynthesis of the plant hormone indole-3-acetic acid from indole-3-acetonitrile: cloning of the Alcaligenes gene and site-directed mutagenesis of cysteine residues.
- Metabolism of Indole-3-Acetic Acid in Arabidopsis1
