A natural variant of a host RNA-dependent RNA polymerase is associated with increased susceptibility to viruses by <i>Nicotiana benthamiana</i>
Bibliographic record
Abstract
Nicotiana benthamiana often displays more intense symptoms after infection by RNA viruses than do other Nicotiana species. Here, we examined the role of RNA-dependent RNA polymerases (RdRPs) in N. benthamiana antiviral defense. cDNAs representing only two genes encoding RdRPs were identified in N. benthamiana. One RdRP was similar in sequence to SDE1/SGS2 required for maintenance of transgene silencing, whereas the second, named NbRdRP1m, was >90% identical in sequence to the salicylic acid (SA)-inducible RdRP from Nicotiana tabacum required for defense against viruses. NbRdRP1m expression was induced by SA treatment or challenge with Tobacco mosaic virus, but the gene and transcript sequences differed from those of other SA-inducible RdRPs in that they contained a 72-nt insert with tandem in-frame stop codons in the 5' portion of the ORF. N. benthamiana plants transformed with an SA-inducible RdRP gene from Medicago truncatula were more resistant to infection by Tobacco mosaic virus, Turnip vein-clearing virus, and Sunn hemp mosaic virus (members of Tobamovirus genus), but not to Cucumber mosaic virus and Potato virus X (members of different genera than the tobamoviruses). Our results indicate that N. benthamiana lacks an active SA- and virus-inducible RdRP and thus is hypersusceptible to viruses normally limited in their accumulation by this RdRP. These findings are significant for those studying virus-induced gene silencing, the hypersensitive response and systemic acquired resistance.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".