Ultraviolet Wavelength Dependence of Photomorphological and Photosynthetic Responses in <i>Brassica napus</i> and <i>Arabidopsis thaliana</i>
Bibliographic record
Abstract
Among the photomorphological responses in plants induced by ultraviolet-B radiation (UVB; 290 nm-320 nm) are leaf asymmetry, leaf thickening and cotyledon curling. We constructed an action spectrum of cotyledon curling in light-grown Brassica napus to characterize the UVB photoreceptor that initiates this response. Cotyledon curling was also characterized in Arabidopsis thaliana. Peak efficiency for this response occurred between 285 and 290 nm. Additionally, UVB-induced changes in epidermal cells from A. thaliana cotyledons were assessed because they are the likely site of UVB photoreception that leads to curling. Investigation of cellular structure, chlorophyll a fluorescence and chlorophyll concentration indicated that cotyledon curling is not concomitant with gross cellular damage or inhibition of photosynthesis, which only occurred in response to wavelengths <280 nm. Many UVB effects are apparently an indirect consequence of UVB radiation, dependent on UVB-mediated increases in reactive oxygen species (ROS) that either act as a signal in the UVB transduction pathway or cause oxidative damage. The cotyledon curling response was impeded by ascorbate and cystine, ROS scavengers and was promoted by H(2)O(2), a ROS. We suggest that following absorption by a UVB chromophore, ROS are generated via photosensitization, ultimately leading to cotyledon curling.
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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 | 0.000 |
| 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".