Molecular Plant-Microbe Interactions (Jun 1998)

Differential Induction of the Arabidopsis thaliana Thi2.1 Gene by Fusarium oxysporum f. sp. matthiolae

  • Petra Epple,
  • Alberto Vignutelli,
  • Klaus Apel,
  • Holger Bohlmann

DOI
https://doi.org/10.1094/MPMI.1998.11.6.523
Journal volume & issue
Vol. 11, no. 6
pp. 523 – 529

Abstract

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The Arabidopsis thaliana Thi2.1 gene is inducible by necrotrophic fungi through a signal transduction pathway different from that for pathogenesis-related (PR) proteins. We have identified three ecotypes that are susceptible (Col-2, Ler, and Ws) and two ecotypes that are resistant (Mt-0 and Uk-4) to spray inoculation with Fusarium oxysporum f. sp. matthiolae. The Thi2.1 transcript level after infection correlates with resistance, being 5 to 10 times higher in the resistant than in the susceptible ecotypes. The β-glucuronidase (GUS) expression of a Thi2.1-promoter-uidA fusion (with a promoter derived from Col-2) is on the average almost 10 times higher in the Uk-4 background than in the Col-2 background. This confirms the results obtained by Northern (RNA) blots and indicates that Uk-4, and probably other resistant ecotypes too, might have a more sensitive recognition system for F. oxysporum f. sp. matthiolae or might have a signal transduction system that gives a higher amplification of the original recognition signal. Our results suggest a role of the Thi2.1 gene in resistance against F. oxysporum f. sp. matthiolae and perhaps other necrotrophic fungi.

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