Arabidopsis mutants simulating disease resistance response
R A Dietrich1, T P Delaney, S J Uknes
1Max Delbrück Laboratory, Köln Federal Republic of Germany.
Cell
|May 20, 1994
Summary
Six Arabidopsis mutants exhibit spontaneous lesions mimicking disease, linked to plant defense responses and enhanced resistance to fungal pathogens. This discovery reveals novel genetic pathways for plant immunity.
Area of Science:
- Plant pathology
- Molecular genetics
- Plant immunity
Background:
- Plant disease resistance is crucial for agriculture.
- Understanding spontaneous lesion formation aids in identifying novel immunity pathways.
- Systemic acquired resistance (SAR) is a key broad-spectrum defense mechanism.
Purpose of the Study:
- To characterize novel Arabidopsis mutants with spontaneous necrotic lesions.
- To investigate the genetic and molecular basis of lesion formation.
- To assess the role of these mutants in plant disease resistance.
Main Methods:
- Genetic analysis of six spontaneous lesion mutants in Arabidopsis.
- Histochemical and molecular marker analysis for disease resistance responses.
- Gene expression profiling for SAR-related genes.
- Pathogen challenge assays with virulent fungal isolates.
Main Results:
- Six mutants, defining at least four loci, were identified with spontaneous necrotic lesions.
- Five mutants showed correlation between lesion formation and markers of plant disease resistance and SAR.
- Four 'lesions simulating disease resistance response' (Isd) mutants exhibited significant resistance to virulent fungal pathogens.
- Lesion formation varied in cell-type preference and could be induced by SAR activators in Isd1 mutants.
Conclusions:
- A novel class of Arabidopsis mutants (Isd) has been identified, exhibiting spontaneous lesions associated with activated defense responses.
- These Isd mutants represent a valuable genetic resource for studying plant immunity and SAR.
- The findings provide new insights into the genetic regulation of plant disease resistance and lesion mimicry.
