Amino Acid Metabolism of Pea Leaves: Diurnal Changes and Amino Acid Synthesis from 15N-Nitrate
Year: 1977
Type: article
Abstract: In the young leaves of pea (Pisum sativum L.) plants, there was a diurnal variation in the levels of amino acids. In the light, total amino nitrogen increased for the first few hours, then stabilized; in the dark, there was a transient decrease followed by a gradual recovery. Asparagine, homoserine, alanine, and glutamine accounted for much of these changes. The incorporation of (15)N into various components of the young leaves was followed after supply of (15)N-nitrate. (15)N appeared most rapidly in ammonia, due to reduction in the leaf, and this process took place predominantly in the light. A large proportion of the primary assimilation took place through the amide group of glutamine, which became labeled and turned over rapidly; labeling of glutamic acid and alanine was also rapid. Asparagine (amide group) soon became labeled and showed considerable turnover. Slower incorporation and turnover were found for aspartic acid, gamma-aminobutyric acid, and homoserine. Synthesis and turnover of all of the amino acids continued at a low rate in the dark. gamma-Aminobutyric acid was the only compound found to label more rapidly in the dark than in the light.
Source: PLANT PHYSIOLOGY
DOI: 10.1104/pp.59.5.915
Institution: Carleton University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2051153048