HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Thavarajah, D. Articles by Schoenau, J. J. Search for Related Content PubMed Articles by Thavarajah, D. Articles by Schoenau, J. J. Agricola Articles by Thavarajah, D. Articles by Schoenau, J. J. Related Collections Other Legumes Crop Physiology & Metabolism Isotopes Nitrogen

CROP PHYSIOLOGY & METABOLISM

Nitrogen Fixation, Amino Acid, and Ureide Associations in Chickpea

^a Department of Plant Sciences, University of Saskatchewan, 51 Campus Dr., Saskatoon, Saskatchewan, Canada S7N5A8
^b Department of Soil Science, University of Saskatchewan, 51 Campus Dr., Saskatoon, Saskatchewan, Canada S7N5A8

^* Corresponding author (rosalind.ball{at}usask.ca)

The metabolic products of nitrogen fixation (N₂) in a legume can be either amides (asparagine, glutamine) or ureides (allantoin and allantoic acid), which are then exported to the shoot via the xylem. Ureides are synthesized solely in the nodules. Chickpea (Cicer arientinum L.) has been separately classified as an amide and as a ureide exporter; however, the exact shoot metabolic products resulting from N₂ fixation are not known. The objectives of this study were (i) to determine the metabolites of N₂ fixation, namely free amino acids and ureides and (ii) to quantify the differences in N₂ fixation for chickpea cultivars in the field by ¹⁵N natural abundance. Leaf ureide concentrations were analyzed at Weeks 6, 7, 8, 9, 10, and 11 after emergence. Free amino acid concentrations were analyzed at Weeks 7, 9, and 11 after emergence. Flax (Linum usitatissimum L., CDC-Bethune) was used as the reference crop for assessment of percentage nitrogen derived from the atmosphere. Two chickpea cultivars, CDC-Anna and Myles, had significantly higher N₂ fixation than the other three tested cultivars. Myles also maintained ureides and amides at a moderate concentration from flowering through reproductive growth. Overall, we found that asparagine and alanine were the major free amino acids, along with ureides, representing likely metabolites from N₂ fixation. Therefore, chickpea should be classified as both an amide and ureide exporter, on the basis of the concentration of both types of N product found in the shoot.

Abbreviations: Ec, electrical conductivity • %Ndfa, percentage nitrogen derived from the atmosphere • SPG, Saskatchewan Pulse Growers

This article has been cited by other articles:

				N. Z. Lupwayi and A. C. Kennedy Grain Legumes in Northern Great Plains: Impacts on Selected Biological Soil Processes Agron. J., November 6, 2007; 99(6): 1700 - 1709. [Abstract] [Full Text] [PDF]