Tissue specific localization of root infection by fungal pathogens: Role of root border cells

Uvini Gunawardena, Martha C. Hawes

Research output: Contribution to journalArticle

64 Scopus citations

Abstract

When roots of pea seedlings were inoculated uniformly with spores of Nectria haematocca or other pea pathogenic fungi, more than 90% developed lesions in the region of elongation within 3 days. More mature regions of most roots as well as the tip showed no visible signs of infection. Yet, microscopic observation revealed that 'mantles,' comprised of fungal hyphae intermeshed with populations of border cells, covered the tips of most roots. After physical detachment of the mantle, the underlying tip of most roots was found to be free of infection. Mantle-covered root tips did not respond to invasion of their border cells by activation of known defense genes unless there was invasion of the tip itself, as revealed by the presence of a lesion. Concomitant with the activation of defense genes was the induction of a cell-wall degrading enzyme whose expression is a marker for renewed production of border cells. Mantle formation did not occur in response to nonpathogens. The data are consistent with the hypothesis that border cells serve as a host-specific 'decoy' that protects root meristems by inhibiting fungal infection of the root tip.

Original languageEnglish (US)
Pages (from-to)1128-1136
Number of pages9
JournalMolecular Plant-Microbe Interactions
Volume15
Issue number11
DOIs
StatePublished - Nov 1 2002

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Keywords

  • Pectinmethylesterase

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science

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