Current Biology
Volume 22, Issue 2, 24 January 2012, Pages 103-112
Journal home page for Current Biology

Article
The HSF-like Transcription Factor TBF1 Is a Major Molecular Switch for Plant Growth-to-Defense Transition

https://doi.org/10.1016/j.cub.2011.12.015Get rights and content
Under an Elsevier user license
open archive

Summary

Background

Induction of plant immune responses involves significant transcription reprogramming that prioritizes defense over growth-related cellular functions. Despite intensive forward genetic screens and genome-wide expression-profiling studies, a limited number of transcription factors have been found that regulate this transition.

Results

Using the endoplasmic-reticulum-resident genes required for antimicrobial protein secretion as markers, we identified a heat-shock factor-like transcription factor that specifically binds to the TL1 (GAAGAAGAA) cis element required for the induction of these genes. Surprisingly, plants lacking this TL1-binding factor, TBF1, respond normally to heat stress but are compromised in immune responses induced by salicylic acid and by microbe-associated molecular pattern, elf18. Genome-wide expression profiling indicates that TBF1 plays a key role in the growth-to-defense transition. Moreover, the expression of TBF1 itself is tightly regulated at both the transcriptional and translational levels. Two upstream open reading frames encoding multiple aromatic amino acids were found 5′ of the translation initiation codon of TBF1 and shown to affect its translation.

Conclusions

Through this unique regulatory mechanism, TBF1 can sense the metabolic changes upon pathogen invasion and trigger the specific transcriptional reprogramming through its target genes expression.

Highlights

► The transcription factor TBF1 binds to the TL1 cis element in vitro and in vivo ► TBF1 controls nearly 3,000 Arabidopsis genes involved in development and immunity ► TBF1 is required for effective SA- and MAMP-induced defense responses ► Translation of TBF1 is regulated by uORFs and sensitive to metabolic changes

Cited by (0)

5

Current address: Department of Biology, University of Alabama at Birmingham, Campbell Hall 369, 1300 University Boulevard, Birmingham, AL 35294, USA

6

Current Address: Department of Pharmacology, University of Colorado School of Medicine, Mail Stop 8303, Box 6511, Aurora, CO 80045, USA