The major chemotaxis gene cluster of <i>Rhizobium leguminosarum</i> bv. <i>viciae</i> is essential for competitive nodulation
Bibliographic record
Abstract
Rhizobium leguminosarum biovar viciae strain 3841 is a motile alpha-proteobacterium that can establish a nitrogen-fixing symbiosis within the roots of pea plants. In order to determine the contribution of chemotaxis to the lifestyle of R. leguminosarum, we have characterized the function of two chemotaxis gene clusters (che1 and che2) in controlling motility behaviour. We have found that both chemotaxis gene clusters modulate the motility swimming bias of R. leguminosarum cells and that the che1 cluster is the major pathway controlling swimming bias and chemotaxis. The che2 cluster also contributes to swimming bias, but has a minor effect on chemotaxis. Using competitive nodulation assays, we have demonstrated that a functional che1 cluster, but not the che2 cluster, promotes competitive nodulation of the peas. This finding implies that the environmental cue(s) triggering chemotaxis of R. leguminosarum bv. viciae cells towards the roots of pea and facilitating colonization are likely to be processed through the che1 cluster despite the contribution of both che clusters to swimming behaviour. A phylogenetic analysis of the distribution of che1 and che2 orthologues in the alpha-proteobacteria together with our results allow us to propose that che1 homologues are major controllers of chemotaxis and host association in the Rhizobiaceae.
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 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".