ARR12 (ARABIDOPSIS RESPONSE REGULATOR 12) is a subfamily-1 type-B response regulator of Arabidopsis thaliana that functions, together with ARR1 and ARR10, as a principal transcriptional effector of cytokinin signaling. It contains an N-terminal phospho-accepting receiver domain, a Myb-related GARP (B-motif) DNA-binding domain and a C-terminal transactivation region, and localizes to the nucleus. Upon phosphotransfer from AHP proteins, ARR12 binds AGATT-type promoter motifs and activates cytokinin-responsive genes, including type-A ARRs. Genetically, arr1 arr12 double and arr1 arr10 arr12 triple mutants show strongly reduced cytokinin sensitivity, enlarged root meristems, reduced shoot growth, altered chlorophyll/anthocyanin content, defective shoot regeneration and callus formation, and enhanced drought tolerance; ARR12 also regulates submergence-induced hypoxia responses via ETP1/ETP2.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000156 phosphorelay response regulator activity | ISS PMID:12068096 Two-component signal transduction pathways in Arabidopsis. | ACCEPT | Summary: ARR12 is a type-B response regulator whose N-terminal receiver domain accepts a phosphoryl group on a conserved aspartate from AHP phosphotransfer proteins, activating its C-terminal Myb-related (GARP) DNA-binding/transactivation output. Reason: Phosphorelay response regulator activity is the defining signalling activity of type-B ARRs. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. PMID:12068096 nuclear AHP translocation enables the activation of B-type ARR proteins, which in turn activate the transcription of A-type ARRs |
| GO:0000160 phosphorelay signal transduction system | IEA GO_REF:0000002 | ACCEPT | Summary: ARR12 is the terminal transcriptional output of the AHK-AHP-ARR multistep phosphorelay. Reason: Core process of type-B ARRs. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. |
| GO:0003677 DNA binding | IDA PMID:40896964 ARR1/12-ETP1/2 model negatively regulates submergence-induce... | MODIFY | Summary: ARR12 binds AGATTTG motifs in target promoters (ChIP-qPCR, Y1H, EMSA). Reason: Direct experimental evidence of DNA binding by the ARR12 Myb-related B-motif, but the binding is motif-specific (AGATTTG), so the general DNA binding term is better replaced by sequence-specific DNA binding (harmonised with the ARR1 review). Proposed replacements: sequence-specific DNA binding Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression |
| GO:0003677 DNA binding | IEA GO_REF:0000002 | MODIFY | Summary: ARR12 binds AGATTTG motifs in target promoters (ChIP-qPCR, Y1H, EMSA). Reason: Direct experimental evidence of DNA binding by the ARR12 Myb-related B-motif, but the binding is motif-specific (AGATTTG), so the general DNA binding term is better replaced by sequence-specific DNA binding (harmonised with the ARR1 review). Proposed replacements: sequence-specific DNA binding Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression |
| GO:0003700 DNA-binding transcription factor activity | IBA GO_REF:0000033 | ACCEPT | Summary: ARR12 is a DNA-binding transcription factor that activates cytokinin primary-response genes such as the type-A ARRs. Reason: Core molecular function of type-B ARRs; DNA binding and transactivation are experimentally demonstrated. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression PMID:16227453 These results indicate that there is functional overlap among the type-B ARRs and that they act as positive regulators of cytokinin signal transduction. |
| GO:0003700 DNA-binding transcription factor activity | IEA GO_REF:0000002 | ACCEPT | Summary: ARR12 is a DNA-binding transcription factor that activates cytokinin primary-response genes such as the type-A ARRs. Reason: Core molecular function of type-B ARRs; DNA binding and transactivation are experimentally demonstrated. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression PMID:16227453 These results indicate that there is functional overlap among the type-B ARRs and that they act as positive regulators of cytokinin signal transduction. |
| GO:0003700 DNA-binding transcription factor activity | ISS PMID:11118137 Arabidopsis transcription factors: genome-wide comparative a... | ACCEPT | Summary: ARR12 is a DNA-binding transcription factor that activates cytokinin primary-response genes such as the type-A ARRs. Reason: Core molecular function of type-B ARRs; DNA binding and transactivation are experimentally demonstrated. PMID:11118137 is a genome-wide transcription factor catalogue whose cached abstract does not mention ARR12, so the experimental ARR12 evidence is quoted instead. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression |
| GO:0005634 nucleus | IBA GO_REF:0000033 | ACCEPT | Summary: ARR12 is a nuclear transcription factor. Reason: Nuclear localization of ARR12 is experimentally established (GUS fusion to full-length ARR12), as for other type-B ARRs. Supporting Evidence: PMID:15173562 beta-Glucuronidase-fusions to full-length ARR2, ARR12, and ARR19 were nuclear localized, consistent with a role in transcriptional regulation. |
| GO:0005634 nucleus | IDA PMID:15173562 Type-B response regulators display overlapping expression pa... | ACCEPT | Summary: ARR12 is a nuclear transcription factor. Reason: Nuclear localization of type-B ARRs is experimentally established. Supporting Evidence: PMID:15173562 beta-Glucuronidase-fusions to full-length ARR2, ARR12, and ARR19 were nuclear localized, consistent with a role in transcriptional regulation. |
| GO:0005634 nucleus | IEA GO_REF:0000120 | ACCEPT | Summary: ARR12 is a nuclear transcription factor. Reason: Nuclear localization of ARR12 is experimentally established (GUS fusion to full-length ARR12), as for other type-B ARRs. Supporting Evidence: PMID:15173562 beta-Glucuronidase-fusions to full-length ARR2, ARR12, and ARR19 were nuclear localized, consistent with a role in transcriptional regulation. |
| GO:0005737 cytoplasm | ISM GO_REF:0000122 | REMOVE | Summary: Sequence-model (ISM) subcellular prediction. Reason: ARR12 is a nuclear transcription factor; nuclear localization is independent of its receiver domain and there is no evidence for a functional cytoplasmic or plastid pool. Supporting Evidence: PMID:15173562 beta-Glucuronidase-fusions to full-length ARR2, ARR12, and ARR19 were nuclear localized, consistent with a role in transcriptional regulation. |
| GO:0006355 regulation of DNA-templated transcription | IBA GO_REF:0000033 | ACCEPT | Summary: ARR12 regulates (activates) transcription of cytokinin-responsive genes. Reason: Core process of a DNA-binding transcription factor. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression |
| GO:0009414 response to water deprivation | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'response to water deprivation' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:26884175 Further drought-tolerance tests of lower-order double and single mutants indicated that ARR1, ARR10, and ARR12 negatively and redundantly control plant responses to drought, with ARR1 appearing to bear the most critical function among the three proteins. PMID:26884175 Expression of all three ARR genes was repressed by dehydration and ABA treatments |
| GO:0009414 response to water deprivation | IEP PMID:26884175 Arabidopsis type B cytokinin response regulators ARR1, ARR10... | KEEP AS NON CORE | Summary: ARR12 contributes to 'response to water deprivation' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:26884175 Further drought-tolerance tests of lower-order double and single mutants indicated that ARR1, ARR10, and ARR12 negatively and redundantly control plant responses to drought, with ARR1 appearing to bear the most critical function among the three proteins. PMID:26884175 Expression of all three ARR genes was repressed by dehydration and ABA treatments |
| GO:0009414 response to water deprivation | IGI PMID:26884175 Arabidopsis type B cytokinin response regulators ARR1, ARR10... | KEEP AS NON CORE | Summary: ARR12 contributes to 'response to water deprivation' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:26884175 Further drought-tolerance tests of lower-order double and single mutants indicated that ARR1, ARR10, and ARR12 negatively and redundantly control plant responses to drought, with ARR1 appearing to bear the most critical function among the three proteins. PMID:26884175 Expression of all three ARR genes was repressed by dehydration and ABA treatments |
| GO:0009611 response to wounding | IEA GO_REF:0000117 | MARK AS OVER ANNOTATED | Summary: ARBA electronic annotation of response to wounding. Reason: Type-B ARR signaling contributes to wound-induced callus formation via cytokinin, but ARR12 is not established as part of the wound response itself. Supporting Evidence: PMID:28904073 We further demonstrate that type-B ARABIDOPSIS RESPONSE REGULATOR-mediated cytokinin signaling regulates the expression of CYCLIN D3;1 (CYCD3;1) |
| GO:0009735 response to cytokinin | IGI PMID:16227453 Multiple type-B response regulators mediate cytokinin signal... | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:16227453 These results indicate that there is functional overlap among the type-B ARRs and that they act as positive regulators of cytokinin signal transduction. PMID:16227453 The triple mutant arr1,10,12 showed almost complete insensitivity to cytokinin under many of the assay conditions used. |
| GO:0009735 response to cytokinin | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. |
| GO:0009736 cytokinin-activated signaling pathway | IBA GO_REF:0000033 | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. PMID:16227453 These results indicate that there is functional overlap among the type-B ARRs and that they act as positive regulators of cytokinin signal transduction. |
| GO:0009736 cytokinin-activated signaling pathway | IEA GO_REF:0000120 | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. PMID:16227453 These results indicate that there is functional overlap among the type-B ARRs and that they act as positive regulators of cytokinin signal transduction. |
| GO:0009736 cytokinin-activated signaling pathway | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:18723577 Our results support a model in which cytokinin regulates a wide array of downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ARR12. |
| GO:0009736 cytokinin-activated signaling pathway | TAS PMID:12068096 Two-component signal transduction pathways in Arabidopsis. | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:12068096 A multistep two-component phosphorelay system with distinct AHK, AHP, and ARR proteins plays a central role in cytokinin signal transduction |
| GO:0010082 regulation of root meristem growth | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of root meristem growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:17363254 cytokinins control the rate of meristematic cell differentiation and thus determine root-meristem size via a two-component receptor histidine kinase-transcription factor signaling pathway |
| GO:0010082 regulation of root meristem growth | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of root meristem growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:17363254 cytokinins control the rate of meristematic cell differentiation and thus determine root-meristem size via a two-component receptor histidine kinase-transcription factor signaling pathway |
| GO:0010082 regulation of root meristem growth | IMP PMID:23482873 Functional characterization of type-B response regulators in... | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of root meristem growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:17363254 cytokinins control the rate of meristematic cell differentiation and thus determine root-meristem size via a two-component receptor histidine kinase-transcription factor signaling pathway |
| GO:0010082 regulation of root meristem growth | IMP PMID:23482873 Functional characterization of type-B response regulators in... | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of root meristem growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:17363254 cytokinins control the rate of meristematic cell differentiation and thus determine root-meristem size via a two-component receptor histidine kinase-transcription factor signaling pathway |
| GO:0010380 regulation of chlorophyll biosynthetic process | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of chlorophyll biosynthetic process' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0010380 regulation of chlorophyll biosynthetic process | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of chlorophyll biosynthetic process' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0010492 maintenance of shoot apical meristem identity | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'maintenance of shoot apical meristem identity' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:28576846 Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells. |
| GO:0010492 maintenance of shoot apical meristem identity | IGI PMID:28576846 Type-B ARABIDOPSIS RESPONSE REGULATORs Specify the Shoot Ste... | KEEP AS NON CORE | Summary: ARR12 contributes to 'maintenance of shoot apical meristem identity' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:28576846 Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells. |
| GO:0031537 regulation of anthocyanin metabolic process | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of anthocyanin metabolic process' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0031537 regulation of anthocyanin metabolic process | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of anthocyanin metabolic process' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0043565 sequence-specific DNA binding | IBA GO_REF:0000033 | ACCEPT | Summary: ARR12 binds specific promoter motifs through its Myb-related B-motif (GARP) domain. Reason: Sequence-specific DNA binding by type-B ARRs is experimentally established for ARR1/ARR2 and ARR12. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression PMID:11135105 Their middle segments, which faintly resemble the mammalian oncogene product Myb, were capable of binding double-stranded DNA in a sequence-specific manner in vitro. |
| GO:0048364 root development | IMP PMID:23482873 Functional characterization of type-B response regulators in... | KEEP AS NON CORE | Summary: ARR12 contributes to 'root development' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. |
| GO:0048367 shoot system development | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'shoot system development' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0048367 shoot system development | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | KEEP AS NON CORE | Summary: ARR12 contributes to 'shoot system development' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0071368 cellular response to cytokinin stimulus | IMP PMID:23482873 Functional characterization of type-B response regulators in... | ACCEPT | Summary: ARR12 is one of the principal type-B ARRs (with ARR10 and ARR12/ARR1) mediating transcriptional responses to cytokinin; higher-order type-B arr mutants are almost completely cytokinin-insensitive. Reason: Core process; extensive genetic evidence from single and higher-order mutants. Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:23482873 ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. |
| GO:0080022 primary root development | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'primary root development' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0080022 primary root development | IGI PMID:18723577 Type B response regulators of Arabidopsis play key roles in ... | KEEP AS NON CORE | Summary: ARR12 contributes to 'primary root development' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0080036 regulation of cytokinin-activated signaling pathway | IEA GO_REF:0000117 | MODIFY | Summary: ARR12 is required for normal cytokinin responsiveness in roots. Reason: ARR12 is an integral component of the cytokinin-activated signaling pathway (its terminal transcription factor), not a separate regulator of it; the pathway term is more accurate. Proposed replacements: cytokinin-activated signaling pathway Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:23482873 ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. |
| GO:0080036 regulation of cytokinin-activated signaling pathway | IMP PMID:23482873 Functional characterization of type-B response regulators in... | MODIFY | Summary: ARR12 is required for normal cytokinin responsiveness in roots. Reason: ARR12 is an integral component of the cytokinin-activated signaling pathway (its terminal transcription factor), not a separate regulator of it; the pathway term is more accurate. Proposed replacements: cytokinin-activated signaling pathway Supporting Evidence: PMID:23482873 Cytokinin responses are predominantly mediated by subfamily 1 members, with cytokinin-mediated effects on root growth and root meristem size correlating with type-B ARR expression levels. PMID:23482873 ARR1, as well as a subset of other subfamily 1 type-B ARRs, restore the cytokinin sensitivity to arr1 arr12. |
| GO:0080113 regulation of seed growth | IEA GO_REF:0000117 | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of seed growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. The electronic annotation is consistent with the experimental data. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:0080113 regulation of seed growth | IMP PMID:23482873 Functional characterization of type-B response regulators in... | KEEP AS NON CORE | Summary: ARR12 contributes to 'regulation of seed growth' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:18723577 The triple mutant exhibited reduced stature due to decreased cell division in the shoot, enhanced seed size, increased sensitivity to light, altered chlorophyll and anthocyanin concentrations, and an aborted primary root with protoxylem but no metaxylem. |
| GO:1990110 callus formation | IGI PMID:28904073 Wounding Triggers Callus Formation via Dynamic Hormonal and ... | KEEP AS NON CORE | Summary: ARR12 contributes to 'callus formation' as a downstream output of type-B ARR-mediated cytokinin transcriptional signaling. Reason: Supported by mutant/genetic interaction data, often in redundant higher-order arr mutants; this is a pleiotropic developmental/physiological output rather than the core molecular role. Supporting Evidence: PMID:28904073 We further demonstrate that type-B ARABIDOPSIS RESPONSE REGULATOR-mediated cytokinin signaling regulates the expression of CYCLIN D3;1 (CYCD3;1) |
| GO:0001216 DNA-binding transcription activator activity | IDA PMID:40896964 ARR1/12-ETP1/2 model negatively regulates submergence-induce... | NEW | Summary: ARR12 activates transcription of target genes through its C-terminal transactivation domain after binding promoter motifs. Reason: Existing annotations use the parent DNA-binding transcription factor activity; the experimental data show that the activity is transcriptional activation, so the more specific child term is warranted. Supporting Evidence: PMID:40896964 ARR1/12 can directly bind to the promoters via the AGATTTG motifs to activate ETP1/2 expression |
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Download this section (compressed HTML)Q: Which target genes are bound by ARR1 versus ARR12 in different tissues, and does ARR12 contribute distinct targets or only dosage to the subfamily-1 type-B ARR output?
Q: How does receiver-domain phosphorylation relieve autoinhibition of type-B ARR DNA binding or transactivation at the structural level?
Experiment: Perform cytokinin-time-course ChIP-seq/DAP-seq for tagged ARR1 and ARR12 expressed from native promoters in the arr1 arr12 background, and compare binding sites and target gene sets.
Hypothesis: ARR1 and ARR12 share most cytokinin-induced binding sites but differ in tissue-specific targets.
Type: ChIP-seq
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