A Plant miRNA Contributes to Antibacterial Resistance by Repressing Auxin Signaling

@article{Navarro2006APM,
  title={A Plant miRNA Contributes to Antibacterial Resistance by Repressing Auxin Signaling},
  author={Lionel Navarro and Patrice Dunoyer and Florence Jay and Benedict C. Arnold and Nihal Dharmasiri and Mark Estelle and Olivier Voinnet and Jonathan D. G. Jones},
  journal={Science},
  year={2006},
  volume={312},
  pages={436 - 439}
}
Plants and animals activate defenses after perceiving pathogen-associated molecular patterns (PAMPs) such as bacterial flagellin. In Arabidopsis, perception of flagellin increases resistance to the bacterium Pseudomonas syringae, although the molecular mechanisms involved remain elusive. Here, we show that a flagellin-derived peptide induces a plant microRNA (miRNA) that negatively regulates messenger RNAs for the F-box auxin receptors TIR1, AFB2, and AFB3. Repression of auxin signaling… 

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References

SHOWING 1-10 OF 48 REFERENCES

The Arabidopsis F-box protein TIR1 is an auxin receptor

It is shown that TIR1 is an auxin receptor mediating transcriptional responses to auxin, and that auxin signalling involves the modification of SCFTIR1, which is an Aux/IAA transcriptional repressor proteins and the ubiquitin–ligase complex SC FTIR1.

Identification of an SCF ubiquitin-ligase complex required for auxin response in Arabidopsis thaliana.

In Arabidopsis, auxin response is dependent on a ubiquitin-ligase (E3) complex called SCFTIR1, which provides new support for a model in which auxin action depends on the regulated proteolysis of repressor proteins.

The F-box protein TIR1 is an auxin receptor

TIR1 is an auxin receptor that mediates Aux/IAA degradation and auxin-regulated transcription and the loss of TIR1 and three related F-box proteins eliminates saturable auxin binding in plant extracts.

Genetics of Aux/IAA and ARF action in plant growth and development

A review of mutations that affect auxin-modulated transcription factors, in particular those in the Aux/IAA and AUXIN RESPONSE FACTOR(ARF) genes, and potential mechanisms for interactions between auxin and light response pathways suggested by these mutants.

The Transcriptional Innate Immune Response to flg22. Interplay and Overlap with Avr Gene-Dependent Defense Responses and Bacterial Pathogenesis1[w]

A substantial overlap was revealed between the Arabidopsis flg22 response and the tobacco Avr9 race-specific defense response, and it is inferred that Pseudomonas syringae pv tomato represses the flagellin-initiated defense response.

Auxin regulates SCFTIR1-dependent degradation of AUX/IAA proteins

It is shown that SCFTIR1 is required for AUX/IAA degradation, and it is proposed that auxin promotes the degradation of this large family of transcriptional regulators, leading to diverse downstream effects.

Auxin-responsive gene expression: genes, promoters and regulatory factors

A molecular approach to investigate auxin signaling in plants has led to the identification of several classes of early/primary auxin response genes, and a family of trans-acting transcription factors that bind with specificity to AuxREs has been characterized.

Susceptible to intolerance--a range of hormonal actions in a susceptible Arabidopsis pathogen response.

The results indicate that the plants response to a virulent pathogen is a composite of multiple signaling pathways, including ethylene and SA action.

Molecular Strategies of Pathogens and Host Plants

This research emphasizes the genes which are responsible for production of toxins, enzymes, and hormones that lead to pathogenicity and specificity in plant-pathogen interactions.