September
2000
, Volume
13
, Number
9
Pages
911
-
921
Authors
Gustavo
Astua-Monge
,
1
Gerald V.
Minsavage
,
1
Robert E.
Stall
,
1
Michael J.
Davis
,
2
Ulla
Bonas
,
3
Jeffrey B.
Jones
1
Affiliations
1Department of Plant Pathology, University of Florida, Gainesville 32611, U.S.A.; 2Department of Plant Pathology, University of Florida, Tropical Research and Education Center, Homestead 33031, U.S.A.; 3Institut für Genetik, Martin-Luther-Universität, 06099 Halle, Germany
Go to article:
RelatedArticle
Accepted 18 May 2000.
Abstract
Tomato race 3 (T3) of Xanthomonas campestris pv. vesicatoria (Xcv) elicits a hypersensitive response (HR) in leaves of Lycopersicon esculentum near-isogenic line (NIL) 216 and pepper genotypes. One cosmid clone (35 kb) selected from a genomic library of a T3 strain induced an HR in all resistant plants. A 1.5-kb active subclone containing the putative avirulence (avr) gene, designated avrXv3, was sequenced. The avrXv3 gene encodes a 654-bp open reading frame (ORF) with no homology to any known gene. Expression studies with a fusion of this gene and uidA indicated that avrXv3 is plant inducible and controlled by the hypersensitivity and pathogenicity (hrp) regulatory system. Mutational analysis and transcription activation assays revealed that AvrXv3 has transcription activation activity in yeast, and that the putative domain responsible for that activity is located at the C terminus of the AvrXv3 protein. Agrobacterium tumefaciens-mediated transient expression confirmed the direct role of AvrXv3 in eliciting the HR in tomato NIL 216 and supported the hypothesis that Avr proteins must be present inside the plant host cell to trigger the HR.
JnArticleKeywords
Page Content
ArticleCopyright
© 2000 The American Phytopathological Society