GLR2.7 Antibody
Description
Overview of GLR2.7
GLR2.7 is a member of the Arabidopsis clade 2 GLRs, which form cation channels involved in calcium (Ca²⁺) signaling during pattern-triggered immunity (PTI) . It is encoded by the AtGLR2.7 gene and clusters tandemly with GLR2.8 and GLR2.9 on chromosome 5 .
2.1. Calcium Signaling and Immune Activation
GLR2.7, alongside GLR2.8 and GLR2.9, forms a functional triad required for PAMP-induced Ca²⁺ spikes:
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Mutant Phenotype: Triple glr2.7/2.8/2.9 mutants exhibit a 25% reduction in cytosolic Ca²⁺ elevation post-PAMP treatment .
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Pathogen Susceptibility: These mutants show increased susceptibility to Pseudomonas syringae infection, comparable to immune-deficient bak1-5 mutants .
| Phenotype | Wild-Type Response | glr2.7/2.8/2.9 Mutant Response |
|---|---|---|
| Flg22-induced Ca²⁺ elevation | 100% | ~75% |
| Bacterial growth (Pto DC3000) | Low | 3–4x increase |
2.2. Transcriptional Regulation
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Core Immunity Response (CIR): GLR2.7 and GLR2.9 are classified as CIR genes, upregulated by diverse PAMPs but not abiotic stresses .
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Co-expression: Chromosomal clustering suggests coordinated regulation with GLR2.8 and GLR2.9 .
Comparative Analysis of GLR Clades
GLRs in Arabidopsis are divided into three clades with distinct roles:
| Clade | Members | Function | Immune Role |
|---|---|---|---|
| Clade 1 | GLR1.1–1.4 | Root development, wound signaling | Limited |
| Clade 2 | GLR2.7–2.9 | PAMP-induced Ca²⁺ signaling | Critical for PTI |
| Clade 3 | GLR3.1–3.7 | Abiotic stress responses | Minor |
Antibodies Targeting GLRs
While no antibody specific to GLR2.7 is documented in the provided sources, antibodies for related GLRs or epitopes include:
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GL7 Antibody: Targets Neu5Ac glycans on mouse B cells (unrelated to plant GLRs) .
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GluR2 Antibody (7G6): Binds human GluR2 (AMPA receptor subunit) .
Research Implications
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Immune Specificity: GLR2.7/2.8/2.9 activation is exclusive to biotic stress, distinguishing PTI from abiotic signaling .
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Therapeutic Potential: Insights into Ca²⁺-mediated immunity could inform crop engineering for disease resistance .
Open Questions
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
Target Background
Q&A
Basic Research Questions
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What is the functional role of GLR2.7 in plant immune responses?
GLR2.7, a clade 2 glutamate receptor-like (GLR) channel in Arabidopsis, mediates calcium (Ca²⁺) signaling during pattern-triggered immunity (PTI). It is part of a heteromeric channel complex (GLR2.7/2.8/2.9) required for elicitor-induced Ca²⁺ influx and defense against pathogens like Pseudomonas syringae . Knockout mutants (e.g., glr2.7/2.8/2.9) show ~25% reduced Ca²⁺ signals upon treatment with flg22, elf18, or Pep1, and increased bacterial susceptibility .Methodological Insight:
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How is GLR2.7 expression detected and quantified in plant tissues?
GLR2.7 transcription is upregulated during immune activation. Key methods include:-
RT-PCR/qPCR: Primers targeting GLR2.7 exons (e.g., AGI code: At2g29100) .
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Promoter-reporter fusions: GLR2.7 promoter-driven GUS staining reveals tissue-specific expression .
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Single-cell RNA-seq: Resolves cell-type-specific expression in immune-responsive tissues .
Example Data:
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Advanced Research Questions
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How to address functional redundancy among GLRs in experimental design?
GLR2.7 operates in a network with GLR2.8 and GLR2.9, complicating single-gene studies. Key strategies:-
Combinatorial mutants: Use higher-order knockouts (e.g., glr2.7/2.8/2.9) to bypass redundancy .
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Pharmacological inhibition: Apply glutamate receptor antagonists (e.g., DNQX) to dissect channel activity .
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Heterologous systems: Express GLR2.7 in Xenopus oocytes to study biophysical properties independently .
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How to resolve contradictions in GLR2.7-related data across studies?
Discrepancies often arise from:-
Genetic background differences: Compare mutants in multiple ecotypes (e.g., Col-0 vs. YC3.6) .
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Elicitor specificity: Test diverse PAMPs/DAMPs (e.g., flg22 vs. oligogalacturonides) .
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Temporal resolution: Use high-speed Ca²⁺ imaging to capture transient signals missed in endpoint assays .
Case Study:
Study Finding Conflict Source Resolution Approach A GLR2.7 required for PTI Elicitor-specific Ca²⁺ signals Multi-elicitor screen B No role in basal defense Genetic redundancy Triple mutant analysis -
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What validation steps ensure specificity of GLR2.7 antibodies?
GPCR antibodies are prone to off-target binding. Critical validation includes:-
Knockout controls: Test antibodies in glr2.7 CRISPR null lines .
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Orthogonal methods: Compare with RNA-seq or autoradiography data .
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Epitope tagging: Use HA/FLAG-tagged GLR2.7 lines for immunoblot cross-verification .
Validation Table:
Antibody Host Species KO Validation Cross-Reactivity Check Recommended Use AbX Rabbit Yes (Fig. S6) None in glr2.8/2.9 IHC, WB -
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How to correlate GLR2.7 expression with immune function?
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Spatiotemporal profiling: Combine promoter-GUS fusions with pathogen infection time courses .
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Co-expression networks: Identify GLR2.7-linked immune genes (e.g., BAK1, CNGCs) via transcriptomics .
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Single-cell Ca²⁺ imaging: Map Ca²⁺ flux to GLR2.7-expressing cells using advanced microscopy .
Key Finding:
GLR2.7/2.8/2.9 triple mutants exhibit 30% higher P. syringae growth vs. wild-type, linking Ca²⁺ signaling to antibacterial defense . -
