Hypersensitive response

LUCAS D. DAURELIO; MARÍA LAURA TONDO; GERMÁN DUNGER; NATALIA GOTTIG; JORGELINA OTTADO; ELENA G. ORELLANO

Plant Bioassays. Section II. Plant-microorganisms interactions.

Studium Press-Series Editor: S. S. Narwal. Co – Editors: C. A. N. Catalán, D. A. Sampietro, M. A. Vattuone and B. Polyticka.

Año: 2009; p. 187 - 206

Plants have evolved to defense themselves against a variety of pathogens like bacteria, viruses and fungi. Hypersensitive response (HR) is a rapid and localized cell death associated with disease resistance. HR is characterized by the rapid death of a limited number of cells in the vicinity of the invading pathogen and its function is thought to restrict or delay further pathogen spread and eventually kill the pathogen. Then, subsequent signalling events induce local and systemic activation of a set of defence responses that play a role in resistance. One of the most rapid plant responses is associated with the oxidative burst, which constitutes the production and accumulation of active oxygen species which can produce toxic effects via DNA damage, protein degradation and modification and lipid peroxidation. Other physiological and molecular modifications correlated with the HR are ion leakage from dead cells into the apoplast, deposition of lignin and callose into the plant cell wall and production of phytoalexins, hydrolytic enzymes and pathogenesis-related proteins.