Nitrogen Fixation, Amino Acid, and Ureide Associations in Chickpea
Bibliographic record
Abstract
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.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".