Present address: Department of Plant Pathology, North Dakota State University, 306 Walster Hall, Fargo, ND 58105-5012, USA.
Nitrogen controls in planta expression of Cladosporium fulvum Avr9 but no other effector genes
Article first published online: 30 JAN 2006
Molecular Plant Pathology
Volume 7, Issue 2, pages 125–130, March 2006
How to Cite
THOMMA, B. P. H. J., BOLTON, M. D., CLERGEOT, P.-H. and DE WIT, P. J. G. M. (2006), Nitrogen controls in planta expression of Cladosporium fulvum Avr9 but no other effector genes. Molecular Plant Pathology, 7: 125–130. doi: 10.1111/j.1364-3703.2006.00320.x
- Issue published online: 30 JAN 2006
- Article first published online: 30 JAN 2006
During growth on its host tomato, the apoplast-colonizing fungal pathogen Cladosporium fulvum secretes several effector proteins. The expression of the Avr9 gene encoding one of these effector proteins has previously been shown to be strongly induced in vitro during nitrogen deprivation. This led to the hypothesis that expression of additional effector genes in C. fulvum could be triggered by nitrogen starvation conditions that are encountered in the host. We now show that expression of most effectors is not affected by varying levels of nitrogen supplementation in vitro. In addition, we demonstrate that the nitrogen response regulator Nrf1 only regulates Avr9 expression during infection of the host, whereas none of the other known effectors is significantly controlled by this transcription factor in planta. Deletion of Nrf1, but not of Avr9, significantly reduces C. fulvum virulence. Therefore, it is concluded that Nrf1 controls, in addition to Avr9, unidentified effector genes that are required for full virulence of C. fulvum.