Quantification of <i>ToxB</i> gene expression and formation of appressoria by isolates of <i>Pyrenophora tritici‐repentis</i> differing in pathogenicity
Bibliographic record
Abstract
Tan spot, caused by the fungus Pyrenophora tritici‐repentis , is an important foliar disease of wheat. The pathogen produces at least three host‐specific toxins, including Ptr ToxB, a 6·6 kDa protein that causes chlorosis in sensitive wheat genotypes and is encoded by the ToxB gene. Using quantitative reverse transcriptase (qRT)‐PCR, transcript levels of ToxB homologues found in virulent (≡ pathogenic) and weakly virulent (≡ weakly pathogenic) race 5 isolates and an avirulent (≡ nonpathogenic) race 4 isolate of the fungus were compared in conidia, mycelia, and in host tissues after inoculation of resistant and susceptible wheat genotypes. Abundance of the ToxB transcript was greatest in the virulent isolate, followed by the weakly virulent and avirulent isolates, and was positively correlated with the development of chlorosis in the susceptible wheat genotype; transcript was detectable in mycelia and conidia of all isolates tested, and levels peaked at 24 h after inoculation of the race 5 isolates onto resistant and susceptible wheat hosts, before disease symptoms developed. Although all isolates could penetrate host epidermal cells to varying degrees, transcript abundance was positively correlated with the greater and more rapid development of appressoria. Therefore Ptr ToxB may have other roles in the basic pathogenic fitness of the fungus and/or in pre‐penetration processes, suggesting that quantitative variation in the virulence of P. tritici‐repentis is related to the extent of ToxB gene expression.
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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".