| Claim/Topic | Key finding | Evidence type | Species/tissue | Citation (context id) | Publication (year; DOI/URL if mentioned in snippets) |
|---|---|---|---|---|---|
| Identity of tomato DET1/hp2 | Tomato high pigment 2 (hp2) is caused by mutation in the tomato homolog of DE-ETIOLATED1 (DET1); dark green (dg) is also reported as an allele of the tomato DET1 homolog. | Foundational genetics; mutant cloning; literature synthesis in later primary papers | *Solanum lycopersicum*; whole plant/fruit | (pqac-00000007, pqac-00000004, pqac-00000002) | Tang et al. 2016, *New Phytologist*, doi:10.1111/nph.13635, https://doi.org/10.1111/nph.13635; Pick et al. 2007, doi:10.1128/MCB.02432-06, https://doi.org/10.1128/mcb.02432-06 |
| DET1 family / pathway placement | DET1 is a conserved negative regulator of light responses/photomorphogenesis and functions with DDB1 and COP10 in the CDD complex, linked to CUL4-based ubiquitin ligase activity. | Mechanistic biochemistry; cross-species comparative evidence; reviews | Plants broadly; tomato relevance inferred and directly linked by tomato genetics | (pqac-00000002, pqac-00000019, pqac-00000020) | Pick et al. 2007, doi:10.1128/MCB.02432-06, https://doi.org/10.1128/mcb.02432-06 |
| Tomato molecular function | In tomato, DET1 is part of a CUL4-DDB1-DET1 (CRL4) E3 ubiquitin ligase complex that mediates ubiquitin-proteasome degradation of regulatory proteins controlling plastid development and pigmentation. | Primary mechanistic study | *S. lycopersicum* fruit/plant cells | (pqac-00000013, pqac-00000010) | Tang et al. 2016, *New Phytologist*, doi:10.1111/nph.13635, https://doi.org/10.1111/nph.13635 |
| Direct substrate: GLK2 | SlGLK2 associates with the CUL4-DDB1-DET1 complex and is degraded by the 26S proteasome; K11 and K253 are key ubiquitination-relevant residues, and impairing CUL4/DDB1/DET1 retards GLK2 degradation. | Co-IP, Y2H, BiFC, ubiquitination assay, MG132 stabilization, mutagenesis | *S. lycopersicum*; fruit/plant cells | (pqac-00000010, pqac-00000013) | Tang et al. 2016, *New Phytologist*, doi:10.1111/nph.13635, https://doi.org/10.1111/nph.13635 |
| Additional reported regulatory targets/partners | Recent expert summaries state that the tomato CUL4-DDB1-DET1 complex regulates plastid level and pigment accumulation by targeting SlGLK2 and SlBBX20, and that SlMBD5 interacts with the complex to influence pigment metabolism. | 2023 expert review / synthesis | *S. lycopersicum* fruit | (pqac-00000018) | Jia et al. 2023, *International Journal of Molecular Sciences*, doi:10.3390/ijms24032750, https://doi.org/10.3390/ijms24032750 |
| Localization from interaction assays | BiFC detected SlGLK2 interaction with SlDET1 (and SlDDB1/SlCUL4) with strong nuclear YFP signal and weaker cytoplasmic signal, supporting nuclear and some cytoplasmic association of the complex. | BiFC in plant cells | *S. lycopersicum* plant cells | (pqac-00000010) | Tang et al. 2016, *New Phytologist*, doi:10.1111/nph.13635, https://doi.org/10.1111/nph.13635 |
| DET1 localization and NLS-related editing | Target-AID-generated SlDET1 edits were placed in the predicted NLS region/exon 11; mutant and WT YFP-SlDET1 both showed signal in nucleus and cytoplasm, so nuclear localization was not abolished in the transient assay. | Base editing; transient expression; confocal microscopy with DAPI | Tobacco leaf transient assay for tomato SlDET1 fusion proteins | (pqac-00000021, pqac-00000022, pqac-00000023) | Hunziker et al. 2022, *Frontiers in Plant Science*, doi:10.3389/fpls.2022.848560, https://doi.org/10.3389/fpls.2022.848560 |
| Specific edited residues in Target-AID line | The edited full-length SlDET1 protein carried double substitutions P479F and A481V within the predicted NLS region; these were proposed to potentially alter CDD-complex interactions. | Sequence-guided base editing and follow-up characterization | Tomato gene; localization tested in tobacco leaves | (pqac-00000021) | Hunziker et al. 2022, *Frontiers in Plant Science*, doi:10.3389/fpls.2022.848560, https://doi.org/10.3389/fpls.2022.848560 |
| Fruit antioxidant/biofortification phenotype | Fruit-specific downregulation of DET1 enhances nutritional antioxidants without detrimental yield effects; carotenoids, tocopherols, phenylpropanoids, flavonoids, anthocyanidins, and total antioxidant capacity increased. | Fruit-specific RNAi; metabolomics/transcriptomics | *S. lycopersicum* fruit | (pqac-00000014) | Enfissi et al. 2010, *The Plant Cell*, doi:10.1105/tpc.110.073866, https://doi.org/10.1105/tpc.110.073866 |
| Quantitative metabolite gains | In DET1-downregulated/hp2-related lines, neurosporene increased about 3- to 17-fold and tocopherol rose up to ~9-fold (TFM7); phenolics were also strongly elevated. | Quantitative metabolite profiling tables | Tomato fruit (breaker/ripe; skin/pericarp) | (pqac-00000009, pqac-00000015, pqac-00000016) | Enfissi et al. 2010, *The Plant Cell*, doi:10.1105/tpc.110.073866, https://doi.org/10.1105/tpc.110.073866 |
| Nutritional relevance statistic | The Enfissi study notes that a single P119 ripe tomato could deliver the RDA of provitamin A, and increased tocopherol reduced the number of fruits needed to meet vitamin E RDA. | Quantitative nutritional interpretation from primary metabolomics study | Tomato fruit | (pqac-00000009) | Enfissi et al. 2010, *The Plant Cell*, doi:10.1105/tpc.110.073866, https://doi.org/10.1105/tpc.110.073866 |
| Hormone-signaling integration | Loss of SlDET1/HP2 alters ethylene and auxin signaling during ripening: higher ethylene sensitivity/signaling output, downregulation of ERF.E4, severe downregulation of Aux/IAA genes, altered ARFs, and additive effects with light on carotenoid-biosynthetic and signaling genes. | Primary transcript/physiology study | Tomato ripening fruit | (pqac-00000012) | Cruz et al. 2018, *Frontiers in Plant Science*, doi:10.3389/fpls.2018.01370, https://doi.org/10.3389/fpls.2018.01370 |
| Heat-stress / pollen phenotype | Under moderate chronic heat stress, hp2 pollen flavonols increased relative to WT (reported as 18% and 280% for two alleles in the peer-reviewed paper), with average 7.8-fold higher viable pollen and better germination competence. | Peer-reviewed physiological study | Tomato pollen under heat stress | (pqac-00000024) | Rutley et al. 2021, *Frontiers in Plant Science*, doi:10.3389/fpls.2021.672368, https://doi.org/10.3389/fpls.2021.672368 |
| Additional heat-stress quantitative details | The 2021 study also reports higher fractions of flavonol-hyperaccumulating pollen in hp2 lines; hp2j reached 35% DPBA-positive pollen under MCHS (9.2-fold above Moneymaker WT in one excerpted analysis), and pollen flavonol induction in hp2j reached up to 17.5-fold for enhanced-DPBA pollen. | Flow cytometry / DPBA staining; figure-based quantitative analysis | Tomato pollen | (pqac-00000025, pqac-00000026) | Rutley et al. 2021, *Frontiers in Plant Science*, doi:10.3389/fpls.2021.672368, https://doi.org/10.3389/fpls.2021.672368 |
| Reproductive outcome under heat | hp2 maintained percentage of fully seeded fruits and seed number per fruit under heat stress, whereas these measures decreased in WT plants. | Whole-plant reproductive phenotype under stress | Tomato fruits/seeds under heat stress | (pqac-00000024, pqac-00000026) | Rutley et al. 2021, *Frontiers in Plant Science*, doi:10.3389/fpls.2021.672368, https://doi.org/10.3389/fpls.2021.672368 |
| Real-world application: breeding/gene editing | Target-AID base editing generated new SlDET1 alleles that increased carotenoid accumulation; combined edits with other carotenoid genes showed additive effects, supporting DET1 as a practical biofortification target. | Gene editing / crop-improvement application | Tomato breeding lines / fruit | (pqac-00000011, pqac-00000021) | Hunziker et al. 2022, *Frontiers in Plant Science*, doi:10.3389/fpls.2022.848560, https://doi.org/10.3389/fpls.2022.848560 |
| Expert perspective / current understanding | Recent reviews frame DET1-containing CUL4 systems as central post-translational regulators of plastid, pigment, and light-response networks in tomato fruit, while broader plant-proteolysis reviews note open questions on how COP1 and DET1 stabilize or destabilize specific signaling factors in context. | 2023–2024 expert review and analysis | Tomato fruit / plants broadly | (pqac-00000018) | Jia et al. 2023, *International Journal of Molecular Sciences*, doi:10.3390/ijms24032750, https://doi.org/10.3390/ijms24032750 |


*Table: This table compiles core evidence for the identity, mechanism, localization, phenotypes, and applications of tomato DET1/hp2. It is useful as a citation-ready summary for functional annotation and recent crop-improvement relevance.*