(of a microorganism) not virulent.
- ‘Concerning biotic stress, plants exposed to virulent and avirulent pathogens respond with a range of defence- and damage-limiting mechanisms.’
- ‘Nonrice isolates were generally avirulent or weakly pathogenic toward rice.’
- ‘The main common defence reaction is the hypersensitive response, characterized by the induction of rapid cell death at the site of the attempted attack by either an avirulent strain of a pathogen or a non-pathogen.’
- ‘Mating is disrupted in gpa3 mutants; since mating is required for pathogenicity, these strains are also avirulent.’
- ‘In Arabidopsis plants infiltrated with avirulent bacteria, specific calcium ‘waves’ were found to occur concurrent with the oxidative burst, leading to the HR.’