Plant Promoter Yeast One-Hybrid Screening Service
Plant Promoter-Protein Interaction Screening
CD BioSciences provides Plant Promoter Yeast One-Hybrid (Y1H) screening services for identifying candidate transcription factors or DNA-binding proteins that interact with a selected plant promoter region or regulatory element.
This service is suitable for studies in which a promoter sequence, cis-acting element, or regulatory motif has been identified and the next objective is to screen for upstream regulators under yeast assay conditions.
Service Overview
Promoter Y1H screening uses a promoter-derived DNA bait to drive reporter gene selection in yeast. Candidate proteins from a plant cDNA library are expressed as activation-domain fusions. Proteins that bind the bait sequence can activate reporter expression and allow yeast growth on selective medium.
The assay is often used after promoter deletion analysis, motif prediction, transcriptome analysis, stress-response studies, hormone-response studies, or candidate gene prioritization. Positive hits from Y1H screening should be followed by targeted validation, such as point-to-point Y1H, EMSA, dual-luciferase reporter assay, or in planta functional analysis.
Promoter Bait Design
Bait design is one of the most important steps in promoter Y1H screening. The selected fragment should preserve the regulatory sequence of interest while limiting non-specific background and construction difficulty.
Figure 1. Common promoter Y1H bait design options for screening and specificity testing.
| Bait Type | Typical Use | Consideration |
|---|---|---|
| Full or long promoter fragment | Exploratory screening when the regulatory region is not narrowed down. | May retain native context, but can increase background or construction complexity. |
| Truncated promoter fragment | Screening after promoter deletion or reporter analysis. | Can focus the assay on a functional promoter interval. |
| Core cis-element or motif | Testing a predicted binding site or stress/hormone-responsive element. | May require tandem repeats or careful flanking sequence design. |
| Mutant motif control | Assessing whether candidate binding depends on a defined motif. | Useful for follow-up validation rather than broad discovery screening. |
Workflow
Figure 2. General workflow for promoter Y1H screening and candidate transcription factor identification.
- Review of promoter sequence, motif information, and research objective
- Promoter bait design and construction strategy selection
- Bait vector and reporter strain construction
- Auto-activation and toxicity testing
- Selection stringency optimization
- cDNA library transformation and screening
- Positive clone picking, confirmation, and sequencing
- Candidate hit annotation and report preparation
Applications
Screen candidate regulators of drought, salinity, cold, heat, pathogen response, or oxidative stress-related promoters.
Evaluate promoter elements associated with ABA, auxin, gibberellin, jasmonate, salicylic acid, or ethylene response.
Identify candidate transcription factors associated with tissue-specific or developmental promoter activity.
Screen or validate proteins that interact with predicted cis-elements, conserved motifs, or engineered mutant controls.
Controls and Limitations
Promoter Y1H screening is a useful discovery method, but it does not reproduce chromatin structure, plant cell compartmentalization, or all cofactor-dependent regulatory conditions. A protein identified by Y1H should be considered a candidate interactor until validated by independent assays.
| Check | Purpose |
|---|---|
| Bait-only auto-activation test | Determines whether the promoter bait activates the reporter without prey protein. |
| Stringency titration | Helps suppress background while maintaining detectable interaction signals. |
| Mutant or truncated bait comparison | Evaluates motif dependence or narrows candidate binding regions. |
| Point-to-point re-testing | Confirms selected bait-prey pairs outside the initial library screen. |
Sample and Information Requirements
- Promoter sequence, motif sequence, or genomic coordinates
- Plant species and gene ID or locus information
- Target tissue, treatment condition, or developmental stage
- Existing promoter activity or motif prediction data, if available
- Preferred cDNA library source or sample material
- Known candidate transcription factors for optional validation
Deliverables
- Promoter bait design summary
- Bait construction and reporter strain information
- Auto-activation and stringency testing records
- Screening plate images and positive clone records
- Positive clone sequencing results
- Candidate transcription factor annotation table
- Project report with interpretation notes
Related Services
For promoter Y1H screening project design, please contact us with the promoter sequence, plant species, and expected library source.
For research use only, not for clinical use.