Skip to main content
padlock icon - secure page this page is secure

Free Content A tomato mutant that shows stunting, wilting, progressive necrosis and constitutive expression of defence genes contains a recombinant Hcr9 gene encoding an autoactive protein

Download Article:
 Download
(PDF)
 
The tomato Cf‐9 gene confers resistance to races of the leaf mould fungus Cladosporium fulvum that carry the Avr9 avirulence gene. Cf‐9 resides at a locus containing five paralogous genes and was isolated by transposon tagging using a modified maize Dissociation (Ds) element. The tagging experiment generated an allelic series of Ds‐induced mutations of Cf‐9, most of which were wild type in appearance. However, one mutant, designated M205, showed stunted growth, wilting, progressive leaf chlorosis and necrosis and constitutive expression of defence genes. The phenotype of M205 was caused by a semidominant, Avr9‐independent mutation that co‐segregated with a Ds element insertion at the Cf‐9 locus. Molecular genetic analysis indicated that the Cf‐9 locus of M205 had undergone recombination, generating a chimeric gene, designated Hcr9‐M205, that comprised an in‐frame fusion between the 5′ coding region of the Cf‐9 paralogue, Hcr9‐9A, and the 3′ coding region of Cf‐9. The presence of a possible excision footprint adjacent to the junction between Hcr9‐9A and Cf‐9, and a Ds insertion at the homologous position in the downstream paralogue Hcr9‐9D, is consistent with recombination between Hcr9‐9A and Cf‐9 promoted by transposition of Ds from Cf‐9 into Hcr9‐9D. Agrobacterium tumefaciens‐mediated transient expression of Hcr9‐M205 in Nicotiana tabacum caused chlorosis and the accumulation of defence gene transcripts, indicating that the protein encoded by this novel Hcr9 gene is autoactive.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Cladosporium fulvum; agroinfiltration; autoactive; lesion mimic; plant disease resistance; transposon

Document Type: Research Article

Affiliations: 1: CSIRO Plant Industry, GPO Box 350, Glen Osmond, SA 5064, Australia, and 2: Sainsbury Laboratory, John Innes Centre, Colney Lane, Norwich, Norfolk NR4 7UH, UK 3: Plant Cell Biology Group, Research School of Biological Sciences, The Australian National University, Canberra, ACT 0200, Australia

Publication date: May 1, 2006

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more