| Claim/annotation (function/localization/regulation) | Evidence type | Key experimental system/conditions | Quantitative data (fold change, log2 ratio, assay units) | Source (authors, year, journal) | URL | Context ID citation |
|---|---|---|---|---|---|---|
| HSP17.7 is the Arabidopsis thaliana At5g12030 gene product, annotated as a cytosolic class II small heat shock protein (AtHsp17.7-CII) in the HSP20/sHSP family | Curated annotation/review synthesis | Arabidopsis sHSP classification and seed/stress expression literature summarized for plant sHSPs | Not applicable | Sun et al., 2002, *Biochim. Biophys. Acta* | https://doi.org/10.1016/S0167-4781(02)00417-7 | (pqac-00000000, pqac-00000002) |
| HSP17.7 accumulates during seed maturation and is abundant in dry seeds, supporting a role in seed maturation/desiccation tolerance | Developmental expression | Arabidopsis seeds across maturation stages; protein/transcript accumulation summarized from primary studies | Begins at mid-maturation; abundant through late maturation and dry seed | Sun et al., 2002, *Biochim. Biophys. Acta* | https://doi.org/10.1016/S0167-4781(02)00417-7 | (pqac-00000000, pqac-00000005) |
| HSP17.7 seed expression depends on ABI3-dependent developmental regulation | Mutant expression analysis | ABI3 knockout/desiccation-intolerant mutant seeds (abi3 lines) lacking normal seed maturation program | Hsp17.7-CII not detectable in ABI3 knockout lines; no fold value reported | Kotak et al., 2007, *The Plant Cell* | https://doi.org/10.1105/tpc.106.048165 | (pqac-00000004, pqac-00000006, pqac-00000014) |
| HSP17.7 is a downstream target of the ABI3→HsfA9 seed developmental transcriptional cascade | Transcriptional regulation/reporter reconstruction | Arabidopsis seed system plus transient reporter assays showing ABI3 activates HsfA9 promoter and HsfA9 activates Hsp promoters | No direct numeric fold value for HSP17.7 promoter activation provided in excerpt | Kotak et al., 2007, *The Plant Cell* | https://doi.org/10.1105/tpc.106.048165 | (pqac-00000004, pqac-00000006) |
| Heat induction of HSP17.7 in siliques does not require ABI3/HsfA9 | Stress-induction RT-PCR/immunoblot | Wild-type and abi3-6 siliques at different developmental stages heat-stressed at 38°C for 2 h | Hsp17.7-CII transcripts induced at comparable levels in heat-stressed WT and abi3-6; no fold value reported | Kotak et al., 2007, *The Plant Cell* | https://doi.org/10.1105/tpc.106.048165 | (pqac-00000007, pqac-00000014) |
| HSP17.7 is regulated by HSFs through heat shock elements (HSEs); ABI3 can enhance HSF-dependent activation on Hsp17.7-type promoters | Regulatory inference supported by promoter studies | Plant sHSP promoter analyses summarized in review; HSE integrity and HSF activation domain required for ABI3-dependent enhancement | No gene-specific fold value for At5g12030 reported | Sun et al., 2002, *Biochim. Biophys. Acta* | https://doi.org/10.1016/S0167-4781(02)00417-7 | (pqac-00000000, pqac-00000002, pqac-00000005) |
| HSP17.7 is strongly inducible by non-heat chemical stress (gallic acid) | Microarray stress induction | Arabidopsis exposed 6 h to allelochemicals in aquaculture medium; Table 2 gene expression profiling | 15.57-fold induction; P=0.02 | Golisz et al., 2008, *Journal of Experimental Botany* | https://doi.org/10.1093/jxb/ern168 | (pqac-00000011, pqac-00000013) |
| HSP17.7 is induced by sulfur dioxide stress as part of defense/stress response | Microarray stress induction | SO2-treated Arabidopsis vs untreated control in defense-related gene expression study | Log2 ratio = 4.0 (~16-fold); P<0.01 | Li & Yi, 2012, *Chemosphere* | https://doi.org/10.1016/j.chemosphere.2011.12.064 | (pqac-00000012) |
| HSP17.7 can specifically repress Arabidopsis HsfA2 activity, indicating a regulatory role beyond generic chaperoning | Reporter assay | Tobacco protoplast Hsf-dependent GUS reporter assay with AtHsfA2 coexpressed with Arabidopsis class II sHSPs | GUS activity (RFU ×10^-3) decreased dose-dependently with increasing AtHsp17.7-CII; exact values not given in excerpt/image summary | Port et al., 2004, *Plant Physiology* | https://doi.org/10.1104/pp.104.042820 | (pqac-00000008, pqac-00000010, pqac-00000017) |
| Repression of AtHsfA2 is selective: AtHsp17.7-CII represses, but the closely related AtHsp17.6-CII does not | Comparative reporter assay | Same tobacco protoplast GUS reporter system comparing Arabidopsis class II sHSP isoforms | AtHsp17.6-CII showed minimal/no repression; assay axis RFU ×10^-3 | Port et al., 2004, *Plant Physiology* | https://doi.org/10.1104/pp.104.042820 | (pqac-00000008, pqac-00000009, pqac-00000017) |
| The AtHsp17.7-CII effect on AtHsfA2 appears species-selective; tomato Hsp17.4-CII did not repress Arabidopsis HsfA2 in the same assay | Comparative reporter assay | Tobacco protoplast Hsf-dependent GUS reporter with AtHsfA2 plus tomato Hsp17.4-CII | Minimal/no effect on GUS activity; assay axis RFU ×10^-3 | Port et al., 2004, *Plant Physiology* | https://doi.org/10.1104/pp.104.042820 | (pqac-00000008, pqac-00000010, pqac-00000017) |
| Direct physical interaction between AtHsp17.7-CII and AtHsfA2 was not detected in non-reporter assays, so the regulatory relationship is strongest at the functional assay level | Interaction assay interpretation | Reporter assays positive, but other interaction assays for Arabidopsis pair negative; contrasted with stronger tomato biochemical interaction data | No quantitative binding constant reported | Port et al., 2004, *Plant Physiology* | https://doi.org/10.1104/pp.104.042820 | (pqac-00000009, pqac-00000016) |
| As a class II cytosolic sHSP, HSP17.7 is inferred to function as an ATP-independent molecular chaperone that binds nonnative proteins and helps prevent irreversible aggregation | Family-level mechanistic evidence/inference | General plant sHSP biochemical literature summarized in review; applies to cytosolic class II proteins including AtHsp17.7 by family/domain membership | No AtHsp17.7-specific kinetic values in excerpt | Sun et al., 2002, *Biochim. Biophys. Acta* | https://doi.org/10.1016/S0167-4781(02)00417-7 | (pqac-00000002, pqac-00000003) |
| Cytosolic/nuclear localization is supported for plant class II sHSPs, but no direct localization assay specific to At5g12030 was identified in the retrieved evidence | Localization by family assignment/inference | Reviews classify class II sHSPs as cytosolic/nuclear; direct AtHsp17.7 localization experiment not extracted here | Not applicable | Tariq et al., 2010, *African Journal of Biotechnology*; Sun et al., 2002, *Biochim. Biophys. Acta* | https://doi.org/10.5897/AJB09.006 ; https://doi.org/10.1016/S0167-4781(02)00417-7 | (pqac-00000002, pqac-00000003) |


*Table: This table summarizes direct and inferred evidence for Arabidopsis thaliana HSP17.7/At5g12030, covering developmental regulation, abiotic stress induction, functional reporter assays, and localization/function inferences. It is useful for separating gene-specific experiments from family-level annotation.*