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Title: ANALYSIS OF THE AVR1-CO39 AVIRULENCE GENE LOCUS FROM MAGNAPORTHE GRISEA

Author
item FARMAN, MARK - UNIVERSITY OF WISCONSIN
item Leong, Sally

Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: A Magnaporthe grisea cultivar specificity gene toward rice cultivar CO39 was previously mapped to one arm of chromosome I between RFLP markers CH5-120H and 5-10-F. These RFLP markers map 11.6 cM and 17.2 cM, respectively, on either side of Avr1-CO39. Using Achilles' cleavage methods, CH5-120H and 5-10-F were shown to be separated by 600 kb. A chromosome walk to Avr1-CO39 was initiated from these markers and over 500 kb have been covered in 20 walking steps. Cosmid clones cosegregating with Avr1-CO39 have been identified and selected clones obtained from the walk were shown to confer avirulence on rice variety CO39 but not 51583 when introduced by transformation in the virulent M. grisea strain Guy11. The DNA conferring avirulence has been delimited to a 1.05 kb region. Four putative open reading frames were identified by DNA sequence analysis and the precise location of the AVR1-CO39 gene is being defined by transcript analysis, site-directed deletion of ATG codons and by introduction of frameshifts into each ORF. Hybridization studies of DNA of the virulent M. grisea strain Guy11 indicates that approximately 20 kb of DNA at the Avr1-CO39 locus is deleted and that a repetitive DNA species is present at the deletion breakpoint. This deletion eliminated AVR1-CO39 from the Guy11 genome.