Brief exposure to low‐pH stress causes irreversible damage to the growing root in Arabidopsis thaliana: pectin–Ca interaction may play an important role in proton rhizotoxicity
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The viability of Arabidopsis thaliana (strain Landsberg) roots exposed to a low pH (4.5 or 4.7) solution that contained 100 microM CaCl(2) was examined by staining with fluorescein diacetate-propidium iodide. The elongation zone of growing roots lost viability within 1-2 h following exposure to low pH, but non-growing roots showed no damage under the same treatment. Low-pH damage in growing roots was irreversible after 1 h incubation at pH 4.5 as judged by regrowth in growing medium at pH 5.6. Growing lateral roots also lost viability in the same treatment, whereas non-growing lateral roots remained viable during and after the treatment. The low-pH damage was ameliorated by the simultaneous application of calcium, indicating the involvement of a calcium-requiring process in overcoming proton toxicity. At pH 5.0, growing roots required 25 microM of calcium to maintain elongation, and at pH 4.8 and pH 4.5 more than 250 microM and 750 microM, respectively. The low-pH damage was ameliorated by divalent cations in the order of Ba2+, approximately Sr2+>/=Ca2+>Mg2+. The monovalent cation K+ showed no ameliorative effect, but borate showed a strong ameliorative effect with Ca2+. These results indicate that the primary target of proton toxicity may be linked to a disturbance of the stability in the pectic polysaccharide network, where calcium plays a key role in plant roots.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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 it