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 HighWire Citing Articles via CrossRef Citing Articles via Web of Science (27) Citing Articles via Google Scholar Google Scholar Articles by Walker, C. D. Articles by Welch, R. M. Search for Related Content PubMed PubMed Citation Articles by Walker, C. D. Articles by Welch, R. M. Agricola Articles by Walker, C. D. Articles by Welch, R. M.

Articles

Effects of Ni Deficiency on Some Nitrogen Metabolites in Cowpeas (Vigna unguiculata L. Walp) ¹

United States Plant, Soil, and Nutrition Laboratory, United States Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853, Department of Agronomy, Waite Agricultural Research Institute, Glen Osmond, South Australia 5064 Australia

Cowpeas grown in nutrient solutions, from which Ni had been removed by a ligand exchange technique, accumulated urea in most tissues. Urea levels were highest (up to 3.1 percent dry weight) in necrotic leaf tips. Urea accumulation in Ni-deficient cowpea tissues amounted to about 1 percent of the total N. The accumulation of urea was presumably associated with the catabolism of N compounds in older tissues and the redistribution of N catabolites within the plant during the reproductive growth. The exclusion of N salts from the nutrient media at a late stage of growth, either with or without added Ni, led to a general amelioration of urea accumulation and a lower level of the related amino acid, arginine, in root and stem tissue. Plant leaves that contained toxic levels of urea and displayed necrotic symptoms had tissue Ni levels ranging from less than 0.01 to 0.15 µg Ni per gram dry weight. Nickel concentrations in tissue from plants not treated with Ni, were initially very low, but increased as the cowpeas matured. Apparently, there was a source of Ni contamination in the Ni-deficient growth media which provided a source of Ni for uptake by the plants during growth. Ureide levels were low and unaffected by Ni deprivation. No evidence for free purines or uric acid accumulation in plant tissues could be found. It is hypothesized that Ni (and urease) participates in the normal N metabolism of these plants during the reproductive phase of growth.

This article has been cited by other articles:

				C. Bai, C. C. Reilly, and B. W. Wood Nickel Deficiency Disrupts Metabolism of Ureides, Amino Acids, and Organic Acids of Young Pecan Foliage Plant Physiology, February 1, 2006; 140(2): 433 - 443. [Abstract] [Full Text] [PDF]