γ-Aminobutyrate transaminase limits the catabolism of γ-aminobutyrate in cold-stressed <i>Arabidopsis</i> plants: insights from an overexpression mutant
Bibliographic record
Abstract
We tested the hypothesis that γ-aminobutyrate transaminase (GABA-T) regulates the supply of succinate semialdehyde for succinate semialdehyde dehydrogenase or NADPH-dependent glyoxylate/succinate semialdehyde reductase 1 (GLYR1) during stress. Constitutive overexpression (OX) lines of GABA-T were generated in Arabidopsis via the floral-dip method for Agrobacterium-mediated transformation. Polymerase chain reaction enabled selection of four transgenic lines with higher GABA-T transcript levels than the wild-type (WT), but assay of cell-free leaf extracts revealed that only OX1 had elevated GABA-T activity. Brief cold treatments (4 °C exposure for 20 min or 1 h in the dark) increased leaf GABA concentrations in both the WT and OX1, but the concentrations in OX1 were consistently lower. These findings confirm that GABA-T limits the catabolism of GABA when its production is stimulated by stress, and suggest a bioengineering strategy for improving the availability of succinate semialdehyde for the Krebs cycle or GLYR1, a potential redox-modulating reaction during stress.
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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 | 0.000 | 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) | 0.001 | 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".