Asparate Transcarbamylase Activity in Etiolated Cowpea Hypocotyls Treated with 2,4-Dichlorophenoxyacetic Acid 1
AUTOR(ES)
Johnson, Lowell B.
RESUMO
Treating etiolated cowpea (Vigna unguiculata) seedlings with 2,4-dichlorophenoxyacetic acid resulted in 2.5-, 3.9-, and 6.5-fold increases in DNA, soluble protein, and RNA, respectively, over untreated controls 84 hours after treatment. Aspartate transcarbamylase activity increased within 12 hours after treatment, and by 84 hours it was almost 12-fold greater than that in the untreated controls. During that time, activity in untreated controls dropped 60%. The assay used 14C-aspartate, which was then separated from the 14C-ureidosuccinate product by Dowex 50 (H+ form) column chromatography. Thin layer chromatography of the reaction product indicated that most of the carbamyl-phosphate-dependent radioactivity co-chromatographed with ureidosuccinate. The reaction has a pH optimum near 10.0 and is inhibited by uridine 5′-phosphate and succinate. The data suggest that aspartate transcarbamylase is important in pyrimidine biosynthesis in 2,4-dichlorophenoxyacetic acid-treated seedlings.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=366257Documentos Relacionados
- Enhanced Deoxyribonucleic Acid Polymerase Activity of Chromatin from Soybean Hypocotyls Treated with 2,4-Dichlorophenoxyacetic Acid 1
- Metabolism of 2,4-Dichlorophenoxyacetic Acid. I. C14O2 Production by Bean Plants Treated with Labeled 2,4-Dichlorophenoxyacetic Acids
- Enhanced Activity of the Soluble Ribonucleic Acid Polymerase from 2,4-Dichlorophenoxyacetic Acid-treated Maize Seedlings 1
- BACTERIAL DECOMPOSITION OF 2,4-DICHLOROPHENOXYACETIC ACID1
- Microbial Decomposition of 2,4-Dichlorophenoxyacetic Acid
