Targeted engineering of <i>Azospirillum brasilense</i> SM with indole acetamide pathway for indoleacetic acid over-expression
Bibliographic record
Abstract
Rhizospheric bacterial strains are known to produce indole-3-acetic acid (IAA) through different pathways, and such IAA may be beneficial to plants at low concentrations. IAA biosynthesis by a natural isolate of Azospirillum brasilense SM was studied and observed to be tryptophan-inducible and -dependent in nature. While our work demonstrated the operation of the indole pyruvic acid pathway, the biochemical and molecular evidence for the genes of the indole acetamide (IAM) pathway were lacking in A. brasilense SM. This led us to use the IAM pathway genes as targets for metabolic engineering, with the aim of providing an additional pathway of IAA biosynthesis and improving IAA levels in A. brasilense SM. The introduction of the heterologous IAM pathway, consisting of the iaaM and iaaH genes, not only increased the IAA levels by threefold but also allowed constitutive expression of the same genes along with efficient utilization of IAM as a substrate. Such an engineered strain showed a superior effect on the lateral branching of sorghum roots as well as the dry weight of the plants when compared with the wild-type strain. Such an improved bioinoculant could be demonstrated to enhance root proliferation and biomass productivity of treated plants compared with the parental strain.
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) | 0.001 | 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".