This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (42) Citing Articles via Google Scholar Google Scholar Articles by Behrend, J. Articles by Mateles, R. I. Search for Related Content PubMed PubMed Citation Articles by Behrend, J. Articles by Mateles, R. I. Agricola Articles by Behrend, J. Articles by Mateles, R. I.

Articles

Nitrogen Metabolism in Plant Cell Suspension Cultures

II. Role of Organic Acids during Growth on Ammonia ¹

^a Laboratory of Applied Microbiology, Institute of Microbiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel

Tobacco cells (Nicotiana tabacum) are capable of growth on ammonia as a sole nitrogen source only when succinate, malate, fumarate, citrate, -ketoglutarate, glutamate, or pyruvate is added to the growth medium. A ratio between the molar concentrations of ammonia to succinate (as a complementary organic acid) in the growth medium of 1.5 was optimal. Succinate had no effect on the rate of uptake of ammonia from the medium into the cells although it did affect the intracellular concentration of ammonia. However, the changes were not sufficient to explain inhibition of growth as being due to ammonia toxicity. The radioactivity from ¹⁴C-succinate was incorporated into malate, glutamate, and aspartate within 2 minutes.

It appears that the role of organic acids is neither connected to ammonium transport nor to relief of ammonia toxicity, but may be related to the need for additional carbon skeletons for synthesis of amino acids.