Transcriptome sequencing uncovers the Avr5 avirulence gene of the tomato leaf mold pathogen Cladosporium fulvum.
Mol Plant Microbe Interact
; 27(8): 846-57, 2014 Aug.
Article
in En
| MEDLINE
| ID: mdl-24678832
ABSTRACT
The Cf-5 gene of tomato confers resistance to strains of the fungal pathogen Cladosporium fulvum carrying the avirulence gene Avr5. Although Cf-5 has been cloned, Avr5 has remained elusive. We report the cloning of Avr5 using a combined bioinformatic and transcriptome sequencing approach. RNA-Seq was performed on the sequenced race 0 strain (0WU; carrying Avr5), as well as a race 5 strain (IPO 1979; lacking a functional Avr5 gene) during infection of susceptible tomato. Forty-four in planta-induced C. fulvum candidate effector (CfCE) genes of 0WU were identified that putatively encode a secreted, small cysteine-rich protein. An expressed transcript sequence comparison between strains revealed two polymorphic CfCE genes in IPO 1979. One of these conferred avirulence to IPO 1979 on Cf-5 tomato following complementation with the corresponding 0WU allele, confirming identification of Avr5. Complementation also led to increased fungal biomass during infection of susceptible tomato, signifying a role for Avr5 in virulence. Seven of eight race 5 strains investigated escape Cf-5-mediated resistance through deletion of the Avr5 gene. Avr5 is heavily flanked by repetitive elements, suggesting that repeat instability, in combination with Cf-5-mediated selection pressure, has led to the emergence of race 5 strains deleted for the Avr5 gene.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plant Diseases
/
Fungal Proteins
/
Gene Expression Regulation, Fungal
/
Cladosporium
/
Solanum lycopersicum
/
Transcriptome
Type of study:
Prognostic_studies
Language:
En
Journal:
Mol Plant Microbe Interact
Journal subject:
BIOLOGIA MOLECULAR
/
BOTANICA
/
MICROBIOLOGIA
Year:
2014
Type:
Article