Synthesis and Interconversion of Amino Acids in Developing Cotyledons of Pea (Pisum sativum L.)

AUTOR(ES)

Macnicol, Peter K.

RESUMO

Freshly isolated cotyledons from 10-day developing pea (Pisum sativum) seeds were fed radiolabeled precursors for 5 hours, and the specific radioactivity of the free and total protein amino acids was determined using a dansylation procedure. When the seven most abundant amino acids in phloem exudate of pea fruits (asparagine, serine, glutamine, homoserine, alanine, aspartate, glycine) were fed singly, their carbon was distributed widely among the aliphatic amino acids, proline and tryptophan; sporadic labeling of tyrosine and histidine also occurred. Feeding of glucose led to relatively greater labeling of aromatic amino acids including phenylalanine. The data support the involvement of known plant pathways in these interconversions. Labeling patterns were consistent with participation of the cyanoalanine pathway in the conversion of serine to homoserine, and with the synthesis of histidine from adenosine. All of the labeled amino acids were incorporated into protein.

Documentos Relacionados

• DNA Strand-Transfer Activity in Pea (Pisum sativum L.) Chloroplasts.
• Properties of an Aminotransferase of Pea (Pisum sativum L.) 1
• Isozymes of β-N-Acetylhexosaminidase from Pea Seeds (Pisum sativum L.)
• Localization of α-Amylase in the Apoplast of Pea (Pisum sativum L.) Stems 1
• Nucleotide sequence of a pea (Pisum sativum L.) beta-1,3-glucanase gene.