WRKY33 is a nuclear group I WRKY transcription factor of Arabidopsis thaliana with two WRKY zinc-finger DNA-binding domains that bind the W-box cis-element (TTGAC[C/T]). It is strongly induced by pathogens, PAMPs and abiotic stresses and is a central transcriptional regulator of defense against necrotrophic fungi such as Botrytis cinerea and Alternaria brassicicola. In resting cells WRKY33 is held in a nuclear complex with MPK4 and the VQ protein MKS1; pathogen-triggered MPK4 activation releases it. It is phosphorylated on N-terminal serines by MPK3 and MPK6 (and on Thr229 by CPK5/CPK6), which enhances its transactivation capacity, and its DNA-binding activity is stimulated by the VQ coactivators SIB1 and SIB2. WRKY33 binds the promoters of the camalexin biosynthetic genes PAD3 (CYP71B15) and CYP71A13, its own promoter (positive feedback) and ALD1, and activates their expression, driving phytoalexin camalexin and pipecolic acid production. It also shapes salicylate/jasmonate/ethylene crosstalk during infection. With WRKY25 and WRKY26 it contributes to thermotolerance, and it has more modest roles in salt tolerance, systemic acquired resistance, pathogen-induced autophagy and phosphate-status-dependent repression of anthocyanin genes.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000976 transcription cis-regulatory region binding | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN001261228): WRKY group I family members bind transcription cis-regulatory regions (W-boxes). Reason: Phylogenetically sound and directly confirmed for WRKY33 by EMSA with W-box competition and by ChIP at PAD3/CYP71A13/ALD1 promoters. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21498677 Inclusion of unlabeled W-box, but not GCC-box or as-1 box, in the binding reaction effectively competed the binding of WRKY33 to the 32 P-labeled W-box probe, demonstrating the specificity of W-box binding activity of WRKY33 protein PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0000976 transcription cis-regulatory region binding | IPI PMID:25352272 Promoter-based integration in plant defense regulation. | ACCEPT | Summary: Yeast one-hybrid binding of WRKY33 to the promoter of AT4G31500 (PMID:25352272). Reason: High-throughput yeast one-hybrid screen detected WRKY33 binding to a promoter fragment. Y1H alone is a weak assay, but it is fully consistent with the well-established sequence-specific W-box binding of WRKY33 shown by EMSA and in planta ChIP (PAD3, CYP71A13, ALD1, its own promoter). The molecular function is core; the individual target promoter is not. Supporting Evidence: PMID:25352272 A systematic yeast one-hybrid study was used to identify hundreds of unique potential regulatory interactions with a nearly complete complement of 21 promoters for the aliphatic glucosinolate pathway PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0000976 transcription cis-regulatory region binding | IPI PMID:25533953 An Arabidopsis gene regulatory network for secondary cell wa... | ACCEPT | Summary: Yeast one-hybrid binding of WRKY33 to the promoter of AT4G31500 (PMID:25533953). Reason: High-throughput yeast one-hybrid screen detected WRKY33 binding to a promoter fragment. Y1H alone is a weak assay, but it is fully consistent with the well-established sequence-specific W-box binding of WRKY33 shown by EMSA and in planta ChIP (PAD3, CYP71A13, ALD1, its own promoter). The molecular function is core; the individual target promoter is not. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0000976 transcription cis-regulatory region binding | IPI PMID:27923776 Establishment of Expression in the SHORTROOT-SCARECROW Trans... | ACCEPT | Summary: Yeast one-hybrid binding of WRKY33 to the promoter of AT2G28710 (PMID:27923776). Reason: High-throughput yeast one-hybrid screen detected WRKY33 binding to a promoter fragment. Y1H alone is a weak assay, but it is fully consistent with the well-established sequence-specific W-box binding of WRKY33 shown by EMSA and in planta ChIP (PAD3, CYP71A13, ALD1, its own promoter). The molecular function is core; the individual target promoter is not. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0000976 transcription cis-regulatory region binding | IPI PMID:30356219 Transcriptional regulation of nitrogen-associated metabolism... | ACCEPT | Summary: Yeast one-hybrid binding of WRKY33 to the promoter of AT1G72330 (PMID:30356219). Reason: High-throughput yeast one-hybrid screen detected WRKY33 binding to a promoter fragment. Y1H alone is a weak assay, but it is fully consistent with the well-established sequence-specific W-box binding of WRKY33 shown by EMSA and in planta ChIP (PAD3, CYP71A13, ALD1, its own promoter). The molecular function is core; the individual target promoter is not. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0003700 DNA-binding transcription factor activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from WRKY family node PTN001261228. Reason: Core molecular function. WRKY33 is a two-WRKY-domain group I transcription factor that binds W-box elements and directly regulates target genes (PAD3, CYP71A13, ALD1, WRKY33 itself). It acts mainly as an activator of defense genes but can also repress (e.g. JAZ genes indirectly, DFR), so the neutral parent term is appropriate. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 |
| GO:0003700 DNA-binding transcription factor activity | IDA PMID:17059405 Arabidopsis WRKY33 transcription factor is required for resi... | ACCEPT | Summary: IDA: WRKY33 is nuclear and binds the TTGACC W-box; mutant and overexpression phenotypes alter defense gene expression. Reason: Core molecular function. WRKY33 is a two-WRKY-domain group I transcription factor that binds W-box elements and directly regulates target genes (PAD3, CYP71A13, ALD1, WRKY33 itself). It acts mainly as an activator of defense genes but can also repress (e.g. JAZ genes indirectly, DFR), so the neutral parent term is appropriate. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21498677 Inclusion of unlabeled W-box, but not GCC-box or as-1 box, in the binding reaction effectively competed the binding of WRKY33 to the 32 P-labeled W-box probe, demonstrating the specificity of W-box binding activity of WRKY33 protein |
| GO:0003700 DNA-binding transcription factor activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO mapping from WRKY domain entries. Reason: Core molecular function. WRKY33 is a two-WRKY-domain group I transcription factor that binds W-box elements and directly regulates target genes (PAD3, CYP71A13, ALD1, WRKY33 itself). It acts mainly as an activator of defense genes but can also repress (e.g. JAZ genes indirectly, DFR), so the neutral parent term is appropriate. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence file:ARATH/WRKY33/WRKY33-deep-research-falcon.md Its primary molecular role is to bind regulatory DNA and activate or repress transcription according to the promoter and signaling context |
| GO:0003700 DNA-binding transcription factor activity | ISS PMID:10785665 The WRKY superfamily of plant transcription factors. | ACCEPT | Summary: ISS from WRKY family classification (PMID:10785665). Reason: Core molecular function. WRKY33 is a two-WRKY-domain group I transcription factor that binds W-box elements and directly regulates target genes (PAD3, CYP71A13, ALD1, WRKY33 itself). It acts mainly as an activator of defense genes but can also repress (e.g. JAZ genes indirectly, DFR), so the neutral parent term is appropriate. Supporting Evidence: PMID:10785665 The WRKY proteins are a superfamily of transcription factors with up to 100 representatives in Arabidopsis PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21498677 Inclusion of unlabeled W-box, but not GCC-box or as-1 box, in the binding reaction effectively competed the binding of WRKY33 to the 32 P-labeled W-box probe, demonstrating the specificity of W-box binding activity of WRKY33 protein |
| GO:0003700 DNA-binding transcription factor activity | ISS PMID:11118137 Arabidopsis transcription factors: genome-wide comparative a... | ACCEPT | Summary: ISS from WRKY family classification (PMID:11118137). Reason: Core molecular function. WRKY33 is a two-WRKY-domain group I transcription factor that binds W-box elements and directly regulates target genes (PAD3, CYP71A13, ALD1, WRKY33 itself). It acts mainly as an activator of defense genes but can also repress (e.g. JAZ genes indirectly, DFR), so the neutral parent term is appropriate. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21498677 Inclusion of unlabeled W-box, but not GCC-box or as-1 box, in the binding reaction effectively competed the binding of WRKY33 to the 32 P-labeled W-box probe, demonstrating the specificity of W-box binding activity of WRKY33 protein |
| GO:0005515 protein binding | IPI PMID:15990873 The MAP kinase substrate MKS1 is a regulator of plant defens... | REMOVE | Summary: Interaction with MKS1 (VQ21), the MPK4 substrate that links MPK4 to WRKY33 (PMID:15990873). Reason: Generic protein binding is uninformative. MKS1 is a VQ protein whose role is to tether WRKY33 to MPK4 and keep it inactive until pathogen-triggered release; there is no evidence it coactivates WRKY33, so transcription coregulator binding is not justified. The interaction is not disputed. Supporting Evidence: PMID:15990873 The interactions of MKS1 with W25 and W33 were also confirmed in vitro using His-tagged MKS1 |
| GO:0005515 protein binding | IPI PMID:18650934 Arabidopsis MAP kinase 4 regulates gene expression through t... | REMOVE | Summary: WRKY33 found in nuclear complexes with MPK4 (via MKS1). Reason: Generic protein binding is uninformative; the association is MKS1-dependent and reflects WRKY33 being held in an inactive MPK4-MKS1 complex rather than a WRKY33 molecular function. The interaction is not disputed. Supporting Evidence: PMID:18650934 in the absence of pathogens, Arabidopsis MAP kinase 4 (MPK4) exists in nuclear complexes with the WRKY33 transcription factor |
| GO:0005515 protein binding | IPI PMID:18650934 Arabidopsis MAP kinase 4 regulates gene expression through t... | REMOVE | Summary: Interaction with MKS1 (VQ21), the MPK4 substrate that links MPK4 to WRKY33 (PMID:18650934). Reason: Generic protein binding is uninformative. MKS1 is a VQ protein whose role is to tether WRKY33 to MPK4 and keep it inactive until pathogen-triggered release; there is no evidence it coactivates WRKY33, so transcription coregulator binding is not justified. The interaction is not disputed. Supporting Evidence: PMID:18650934 in the absence of pathogens, Arabidopsis MAP kinase 4 (MPK4) exists in nuclear complexes with the WRKY33 transcription factor |
| GO:0005515 protein binding | IPI PMID:21203436 Arabidopsis MKS1 is involved in basal immunity and requires ... | REMOVE | Summary: Interaction with MKS1 (VQ21), the MPK4 substrate that links MPK4 to WRKY33 (PMID:21203436). Reason: Generic protein binding is uninformative. MKS1 is a VQ protein whose role is to tether WRKY33 to MPK4 and keep it inactive until pathogen-triggered release; there is no evidence it coactivates WRKY33, so transcription coregulator binding is not justified. The interaction is not disputed. Supporting Evidence: PMID:21203436 MPK4 interacts with domain 1 (#1) of MKS1, WRKY33 interacts with domain 2 (#2) of MKS1 |
| GO:0005515 protein binding | IPI PMID:21395886 A critical role of autophagy in plant resistance to necrotro... | REMOVE | Summary: Interaction with autophagy protein ATG18a. Reason: Generic protein binding is uninformative and no specific activity of WRKY33 is implied by the ATG18a interaction. The interaction is not disputed. Supporting Evidence: PMID:21395886 ATG18a, a critical autophagy protein in Arabidopsis, interacts with WRKY33 |
| GO:0005515 protein binding | IPI PMID:21990940 Arabidopsis sigma factor binding proteins are activators of ... | MODIFY | Summary: Interaction with SIB1 (VQ23), a VQ-motif coactivator that binds the C-terminal WRKY domain and stimulates WRKY33 DNA binding. Reason: Generic protein binding is uninformative. Here the partner is a demonstrated coactivator of WRKY33 (enhances its DNA-binding activity and its defense function), so transcription coregulator binding captures the functional meaning of the interaction. Proposed replacements: transcription coregulator binding Supporting Evidence: PMID:21990940 The two VQ motif-containing proteins recognize the C-terminal WRKY domain and stimulate the DNA binding activity of WRKY33 PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005515 protein binding | IPI PMID:22535423 Structural and functional analysis of VQ motif-containing pr... | REMOVE | Summary: Y2H interaction of WRKY33 C-terminal WRKY domain with VQ protein UniProtKB:Q1G3U8 from a family-wide VQ screen. Reason: Generic protein binding is uninformative. The VQ proteins are proposed cofactors of group I WRKYs, but coactivation of WRKY33 by these particular VQ proteins (VQ1, VQ10) was not demonstrated in the abstract; the interaction itself is not disputed. Supporting Evidence: PMID:22535423 Arabidopsis VQ proteins interacted specifically with the C-terminal WRKY domains of group I and the sole WRKY domains of group IIc WRKY proteins PMID:22535423 most likely by acting as cofactors of group I and IIc WRKY transcription factors |
| GO:0005515 protein binding | IPI PMID:22535423 Structural and functional analysis of VQ motif-containing pr... | REMOVE | Summary: Y2H interaction of WRKY33 C-terminal WRKY domain with VQ protein UniProtKB:Q8VYI5 from a family-wide VQ screen. Reason: Generic protein binding is uninformative. The VQ proteins are proposed cofactors of group I WRKYs, but coactivation of WRKY33 by these particular VQ proteins (VQ1, VQ10) was not demonstrated in the abstract; the interaction itself is not disputed. Supporting Evidence: PMID:22535423 Arabidopsis VQ proteins interacted specifically with the C-terminal WRKY domains of group I and the sole WRKY domains of group IIc WRKY proteins PMID:22535423 most likely by acting as cofactors of group I and IIc WRKY transcription factors |
| GO:0005634 nucleus | IBA GO_REF:0000033 | ACCEPT | Summary: IBA nucleus (is_active_in). Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005634 nucleus | IDA PMID:17059405 Arabidopsis WRKY33 transcription factor is required for resi... | ACCEPT | Summary: IDA nuclear localization (PMID:17059405). Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005634 nucleus | IDA PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | ACCEPT | Summary: IDA nuclear localization (PMID:18839316). Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005634 nucleus | IDA PMID:21990940 Arabidopsis sigma factor binding proteins are activators of ... | ACCEPT | Summary: IDA nuclear localization (PMID:21990940). Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005634 nucleus | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt SubCell mapping. Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0005634 nucleus | ISM GO_REF:0000122 | ACCEPT | Summary: AtSubP prediction. Reason: WRKY33 is a nuclear transcription factor: GFP fusion is nuclear, BiFC with SIBs is nuclear, and it occupies target promoters by ChIP. Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21990940 Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells |
| GO:0006355 regulation of DNA-templated transcription | IBA GO_REF:0000033 | ACCEPT | Summary: Regulation of DNA-templated transcription, from WRKY family IBA/InterPro mapping. Reason: Core process for a sequence-specific transcription factor; supported directly by ChIP and target expression data. Supporting Evidence: PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 PMID:21498677 WRKY33 functions downstream of MPK3/MPK6 in reprogramming the expression of camalexin biosynthetic genes, which drives the metabolic flow to camalexin production in Arabidopsis challenged by pathogens |
| GO:0006355 regulation of DNA-templated transcription | IEA GO_REF:0000002 | ACCEPT | Summary: Regulation of DNA-templated transcription, from WRKY family IBA/InterPro mapping. Reason: Core process for a sequence-specific transcription factor; supported directly by ChIP and target expression data. Supporting Evidence: PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 PMID:21498677 WRKY33 functions downstream of MPK3/MPK6 in reprogramming the expression of camalexin biosynthetic genes, which drives the metabolic flow to camalexin production in Arabidopsis challenged by pathogens |
| GO:0006970 response to osmotic stress | IEP PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | KEEP AS NON CORE | Summary: IEP: WRKY33 transcript induced by abiotic stress (response to osmotic stress). Reason: Expression-pattern evidence only; documents that WRKY33 is stress-inducible, not that it executes the response. Retained as non-core context. Supporting Evidence: PMID:18839316 which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling |
| GO:0009408 response to heat | IEP PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | KEEP AS NON CORE | Summary: IEP: WRKY33 expression responds to heat. Reason: Expression evidence only. Note that a later study reports WRKY33 is repressed by high temperature; either way it is a responsive expression change, not core function. Supporting Evidence: PMID:18839316 which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling PMID:21336597 Expression of WRKY25 and WRKY26 was induced upon treatment with high temperature, whereas WRKY33 expression was repressed |
| GO:0009409 response to cold | IEP PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | KEEP AS NON CORE | Summary: IEP: WRKY33 transcript induced by abiotic stress (response to cold). Reason: Expression-pattern evidence only; documents that WRKY33 is stress-inducible, not that it executes the response. Retained as non-core context. Supporting Evidence: PMID:18839316 which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling |
| GO:0009414 response to water deprivation | IEP PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | KEEP AS NON CORE | Summary: IEP: WRKY33 transcript induced by abiotic stress (response to water deprivation). Reason: Expression-pattern evidence only; documents that WRKY33 is stress-inducible, not that it executes the response. Retained as non-core context. Supporting Evidence: PMID:18839316 which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling |
| GO:0009627 systemic acquired resistance | IMP PMID:30228125 A MPK3/6-WRKY33-ALD1-Pipecolic Acid Regulatory Loop Contribu... | KEEP AS NON CORE | Summary: IMP: SAR and pipecolic acid accumulation are compromised in wrky33; WRKY33 binds the ALD1 promoter. Reason: WRKY33 acts upstream of SAR as the MPK3/MPK6-regulated transcriptional activator of ALD1 (pipecolic acid biosynthesis). Genetically solid, but its role is regulatory and secondary to its core necrotroph defense function. Supporting Evidence: PMID:30228125 ALD1 expression, Pip accumulation, and SAR were compromised in mutants defective in the MPK3/6-regulated transcription factor WRKY33 PMID:30228125 Chromatin immunoprecipitation showed that WRKY33 binds to the ALD1 promoter |
| GO:0009651 response to salt stress | IMP PMID:18839316 Functional characterization of Arabidopsis NaCl-inducible WR... | KEEP AS NON CORE | Summary: IMP: wrky33 mutants show moderately increased NaCl sensitivity; overexpression increases salt tolerance. Reason: Mild loss-of-function phenotype with redundancy; a genuine but peripheral abiotic stress role of this transcription factor. Supporting Evidence: PMID:18839316 wrky33 null mutants and wrky25wrky33 double mutants showed only a moderate increase in NaCl-sensitivity, suggesting functional redundancy with other transcription factors PMID:18839316 overexpression of WRKY25 or WRKY33 was sufficient to increase Arabidopsis NaCl tolerance, while increasing sensitivity to ABA |
| GO:0010120 camalexin biosynthetic process | IMP PMID:18650934 Arabidopsis MAP kinase 4 regulates gene expression through t... | MODIFY | Summary: IMP: wrky33 mutants are impaired in PAD3 induction and camalexin accumulation; WRKY33 binds the PAD3 promoter. Reason: WRKY33 does not catalyse any step of camalexin biosynthesis; the enzymes CYP79B2/B3, CYP71A13 and PAD3 (CYP71B15) do. WRKY33 binds the PAD3 and CYP71A13 promoters and activates their transcription downstream of MPK3/MPK6. The process it participates in is therefore positive regulation of camalexin biosynthesis, matching the term used for MPK3 in this repository. Proposed replacements: positive regulation of camalexin biosynthetic process Supporting Evidence: PMID:18650934 WRKY33 targets the promoter of PHYTOALEXIN DEFICIENT3 (PAD3) encoding an enzyme required for the synthesis of antimicrobial camalexin PMID:18650934 wrky33 mutants are impaired in the accumulation of PAD3 mRNA and camalexin production upon infection PMID:21498677 WRKY33 functions downstream of MPK3/MPK6 in reprogramming the expression of camalexin biosynthetic genes, which drives the metabolic flow to camalexin production in Arabidopsis challenged by pathogens PMID:22392279 For CYP71A13 , we observed strong inducible binding at −2,800 bp, again indicating direct positive regulation by WRKY33 file:ARATH/WRKY33/WRKY33-deep-research-falcon.md WRKY33 does not itself catalyze camalexin synthesis |
| GO:0010508 positive regulation of autophagy | IMP PMID:21395886 A critical role of autophagy in plant resistance to necrotro... | KEEP AS NON CORE | Summary: IMP: B. cinerea-induced ATG18a expression and autophagy are compromised in wrky33. Reason: Reasonable regulatory annotation (WRKY33 is required for pathogen induction of autophagy genes), but indirect and peripheral to its core role. Supporting Evidence: PMID:21395886 Induction of ATG18a and autophagy by B. cinerea was compromised in the wrky33 mutant |
| GO:0034605 cellular response to heat | IMP PMID:21336597 Arabidopsis thaliana WRKY25, WRKY26, and WRKY33 coordinate i... | KEEP AS NON CORE | Summary: IMP: double/triple mutants with WRKY25/WRKY26 have reduced thermotolerance; overexpression enhances it. Reason: Phenotype is largely seen in higher-order mutants (redundancy); WRKY33 contributes to transcriptional control of heat-inducible genes. Non-core. Supporting Evidence: PMID:21336597 wrky25wrky26 and wrky25wrky33 double mutants and the wrky25wrky26wrky33 triple mutants showed substantially increased susceptibility to heat stress PMID:21336597 the three WRKY transcription factors modulate transcriptional changes of heat-inducible genes in response to heat treatment |
| GO:0042742 defense response to bacterium | IMP PMID:17059405 Arabidopsis WRKY33 transcription factor is required for resi... | KEEP AS NON CORE | Summary: IMP from Zheng et al. 2006. Reason: The cited abstract states that wrky33 loss-of-function mutants are unaltered toward virulent P. syringae and that overexpression increases bacterial susceptibility, so the effect in this paper is a gain-of-function modulation. Later work (WRKY33 required for MAPK-induced ALD1/Pip and SAR after Pto AvrRpt2) supports some role against bacteria, so the annotation is retained as non-core rather than removed; full text not available to check the curator basis. Supporting Evidence: PMID:17059405 The wrky33 mutants do not show altered responses to a virulent strain of the bacterial pathogen Pseudomonas syringae, although the ectopic expression of WRKY33 results in enhanced susceptibility to this pathogen PMID:30228125 ALD1 expression, Pip accumulation, and SAR were compromised in mutants defective in the MPK3/6-regulated transcription factor WRKY33 |
| GO:0043565 sequence-specific DNA binding | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO sequence-specific DNA binding. Reason: Correct: WRKY33 binds the W-box TTGACC in a sequence-specific manner (lost when mutated). Supporting Evidence: PMID:17059405 WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence PMID:21498677 Inclusion of unlabeled W-box, but not GCC-box or as-1 box, in the binding reaction effectively competed the binding of WRKY33 to the 32 P-labeled W-box probe, demonstrating the specificity of W-box binding activity of WRKY33 protein |
| GO:0050832 defense response to fungus | IMP PMID:17059405 Arabidopsis WRKY33 transcription factor is required for resi... | ACCEPT | Summary: IMP: wrky33 mutants are highly susceptible to Botrytis cinerea and Alternaria brassicicola; overexpression increases resistance. Reason: Strongest and best-replicated phenotype of WRKY33, and the gene product does work in this response as the transcription factor that reprograms defense gene expression (camalexin genes, redox, hormone crosstalk genes) after infection. Camalexin regulation explains only part of the resistance, so the broader process term is warranted alongside positive regulation of camalexin biosynthesis. Supporting Evidence: PMID:17059405 mutations of the Arabidopsis WRKY33 gene encoding a WRKY transcription factor cause enhanced susceptibility to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola concomitant with reduced expression of the jasmonate-regulated plant defensin PDF1.2 gene PMID:17059405 Ectopic over-expression of WRKY33, on the other hand, increases resistance to the two necrotrophic fungal pathogens PMID:22392279 genes involved in redox homeostasis, SA signaling, ethylene-JA-mediated cross-communication, and camalexin biosynthesis were identified as direct targets of WRKY33 PMID:22392279 we found that WRKY33 is not absolutely essential to promote Botrytis -induced camalexin production |
| GO:0070370 cellular heat acclimation | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: IBA cellular heat acclimation from node PTN008629574 (WRKY25/26/33 clade). Reason: Consistent with redundant WRKY25/WRKY26/WRKY33 thermotolerance phenotypes. The clade-level placement is reasonable; this is a peripheral role of WRKY33. Supporting Evidence: PMID:21336597 wrky25wrky26 and wrky25wrky33 double mutants and the wrky25wrky26wrky33 triple mutants showed substantially increased susceptibility to heat stress PMID:21336597 the three WRKY transcription factors modulate transcriptional changes of heat-inducible genes in response to heat treatment |
| GO:0070370 cellular heat acclimation | IMP PMID:21336597 Arabidopsis thaliana WRKY25, WRKY26, and WRKY33 coordinate i... | KEEP AS NON CORE | Summary: IMP: double/triple mutants with WRKY25/WRKY26 have reduced thermotolerance; overexpression enhances it. Reason: Phenotype is largely seen in higher-order mutants (redundancy); WRKY33 contributes to transcriptional control of heat-inducible genes. Non-core. Supporting Evidence: PMID:21336597 wrky25wrky26 and wrky25wrky33 double mutants and the wrky25wrky26wrky33 triple mutants showed substantially increased susceptibility to heat stress PMID:21336597 the three WRKY transcription factors modulate transcriptional changes of heat-inducible genes in response to heat treatment |
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Q: Should defense response to fungus be kept for transcription factors such as WRKY33, or replaced by positive regulation of defense response to fungus once the regulated effector genes are annotated?
Experiment: Genome-wide ChIP-seq of phospho-null and phospho-mimic WRKY33 after Botrytis infection, combined with targeted rescue of individual direct targets in wrky33, to determine which targets account for resistance.
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