Atnaseo, Chuthamat , Erickson, Larry R. , Goodwin, Paul H. .
Induction of disease resistance due to infiltration of Agrobacterium tumefaciens into leaves of Nicotiana benthamiana.
Agrobacterium tumefaciens is a bacterial plant pathogen that infects crowns and stems of plants resulting in gall symptoms. A. tumefaciens is also widely used for transiently expressing foreign genes in plants by a process known as Agro-infiltration. Agro-infiltration of laboratory (no T-DNA transfer) strains into leaves of Nicotiana benthamiana resulted in increased resistance to subsequent inoculation by the anthracnose pathogen, Colletotrichum destructivum. This was determined by a reduction of up to 80% in the anthracnose lesions per leaf indicating that A. tumefaciens causes acquired resistance in N. benthamiana. A variety of wild-type strains also induced resistance to C. destructivum. To determine the factors responsible for this, leaves were infiltrated with A. tumefaciens Vir gene mutants and mutants of genes for possible pathogen-associated molecular patterns (PAMPs). Among the different mutant strains tested, only those with a mutation in genes associated with the type IV secretion system (T4SS) lost their ability to induce acquired resistance. Components of the T4SS and proteins that pass through it are involved in acquired resistance, but neither T-DNA nor other putative PAMP genes that code for flagella proteins and proteins that require transportation by the twin-arginine translocation (TAT) pathway are involved in acquired resistance. This raises concern about using Agro-infiltration to transiently express genes involved in disease resistance as the Agro-infiltration itself can increase the level of resistance in the plants.
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1 - University of Guelph, Department of Plant Agriculture, Guelph, Ontario, N1G 2W1, Canada
2 - University of Guelph, Department of Plant Agriculture
3 - University of Guelph, Department of Environmental Biology
type IV secretion system
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM