Open AccessFunctional Expression of Cf9 and Avr9 Genes in Brassica napus Induces Enhanced Resistance to Leptosphaeria maculans
Author(s) -
Caroline Hennin,
Monica Höfte,
Elke Diederichsen
Publication year - 2001
Publication title -
molecular plant-microbe interactions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.565
H-Index - 153
eISSN - 1943-7706
pISSN - 0894-0282
DOI - 10.1094/mpmi.2001.14.9.1075
Subject(s) - leptosphaeria maculans , elicitor , biology , gene , r gene , plant disease resistance , transgene , microbiology and biotechnology , botany , genetics
The tomato Cf9 resistance gene induces an Avr9-dependent hypersensitive response (HR) in tomato and transgenic Solanaceae spp. We studied whether the Cf9 gene product responded functionally to the corresponding Avr9 gene product when introduced in a heterologous plant species. We successfully expressed the Cf9 gene under control of its own promoter and the Avr9 or Avr9R8K genes under control of the p35S 1 promoter in transgenic oilseed rape. We demonstrated that the transgenic oilseed rape plants produced the Avr9 elicitor with the same specific necrosis-inducing activity as reported for Cladosporium fulvum. An Avr9-dependent HR was induced in Cf9 oilseed rape upon injection of intercellular fluid containing Avr9. We showed Avr9-specific induction of PR1, PR2, and Cxc750 defense genes in oilseed rape expressing Cf9. Cf9 × Avr9 oilseed rape did not result in seedling death of the F 1 progeny, independent of the promoters used to express the genes. The F 1 (Cf9 × Avr9) plants, however, were quantitatively more resistant to Leptosphaeria maculans. Phytopathological analyses revealed that disease development of L. maculans was delayed when the pathogen was applied on an Avr9-mediated HR site. We demonstrate that the Cf9 and Avr9 gene can be functionally expressed in a heterologous plant species and that the two components confer an increase in disease resistance.