The <i>vtc4</i> Gene Influences Polyphosphate Storage, Morphogenesis, and Virulence in the Maize Pathogen <i>Ustilago maydis</i>
Bibliographic record
Abstract
The maize pathogen Ustilago maydis switches from budding to filamentous, dikaryotic growth in response to environmental signals including nutrient status, growth in the host, and the presence of mating pheromones. The filamentous dikaryon is capable of proliferating within host tissue to cause disease symptoms including tumors. The transition from yeast cells to hyphal filaments is regulated by a mitogen-activated protein kinase cascade and a cyclic-AMP-protein kinase A (PKA) pathway. Serial analysis of gene expression with PKA mutants identified orthologs of components of the PHO phosphate acquisition pathway as transcriptional targets of the PKA pathway, and these included genes for Pho84, an acid phosphatase, and the vacuolar transport chaperones Vtc1 and Vtc4. In Saccharomyces cerevisiae, Vtc4p is required during the fusion of inorganic-phosphate-containing vesicles to the vacuolar membrane and the consequent accumulation of phosphate stored as polyphosphate (polyP) in the vacuole. We found that deletion of vtc4 in U. maydis also reduced polyP stored in vacuoles. Intriguingly, Deltavtc4 mutants possessed a filamentous cellular morphology, in contrast to the budding, yeast-like growth of the wild-type parent. The Deltavtc4 mutants also displayed decreased symptom development and reduced proliferation in planta. The interaction with PKA signaling was further investigated by the generation of Deltavtc4 ubc1 double mutants. Deletion of vtc4 completely suppressed the multiple-budded phenotype of a Deltaubc1 mutant, indicating that polyP stores are essential for this PKA-induced trait. Overall, this study reveals a novel role for PKA-regulated polyP accumulation in the control of fungal morphogenesis and virulence.
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".