Infection of tobacco with different <i>Pseudomonas syringae</i> pathovars leads to distinct morphotypes of programmed cell death
Bibliographic record
Abstract
Tobacco plants (Nicotiana tabacum cv. Xanthi-nc) infiltrated with either of two pathovars of Pseudomonas syringae- an avirulent strain of P. syringae pv. tabaci (Pst) or the non-host pathogen P. syringae pv. maculicola M2 (Psm) - developed a hypersensitive response (HR). There were considerable differences in HR phenotype, timing and sequence of cell dismantling between the two pathosystems. Following Psm infiltration, the first macroscopic signs were visible at 4.5 h post-infiltration (hpi). Simultaneously, increased plasma membrane permeability was observed, suggesting that the loss of cell membrane integrity initiates the macroscopic HR evoked by Psm. In contrast, after Pst treatment there was a distinct time lapse between the first signs of tissue collapse (9 hpi) and the occurrence of plasma membrane discontinuity (12 hpi). Ultrastructural studies of cells undergoing the HR triggered by Psm and Pst revealed distinct patterns of alterations in morphology of organelles. Moreover, while different forms of nuclear degeneration were observed in leaf zones infiltrated with Pst, we failed to detect any abnormalities in the nuclei of Psm-treated tissue. In addition, application of synthetic caspase inhibitors (Ac-DEVD-CHO, Ac-YVAD-CMK) abolished HR induced by Pst, but not Psm. Our observations suggest that different cell death mechanisms are executed in response to Psm and Pst. Interestingly, pre-inoculation with Pst, but not with Psm, induced a long-distance acquired resistance (LDAR) response, even though locally a typical set of defense responses, including acquired resistance, was activated locally in response to Psm. The failure of Psm to induce LDAR may be due to the rapid degeneration of bundle sheath cells resulting from Psm infection.
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How this classification was reachedexpand
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 | 0.000 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".