SYSTEMIC ACQUIRED RESISTANCE SIGNALING IN POTATO

Authors: Navarre, Duroy - Roy; Mayo, David

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2003
Publication Date: 3/1/2004
Citation: Navarre, D.A., Mayo, D. 2004. Systemic acquired resistance signaling in potato. American Society of Plant Biologists Annual Meeting. 81:76.

Interpretive Summary:

Technical Abstract: We are interested in using Systemic Acquired Resistance (SAR) as an environmentally friendly alternative to pesticides for disease control in potato. However, successful utilization of SAR will likely require optimization for each crop. Salicylic acid-mediated defense signaling in potato has significant differences relative to the tobacco and Arabidopsis model systems. Potato has high constitutive levels of salicylates in all tissues examined. SA levels were the highest in leaves and flowers, with concentrations of up to 15 mg/gram fresh weight. Relative to Arabidopsis or tobacco, high SA levels were also found in stems, roots and tubers. Potato leaves have a constitutive level of PR-1 expression and may exhibit a differential competence for SAR induction. In some cases, little or no increase in PR-1 gene expression was seen after treatment with SAR inducers. Curiously, potato can also exhibit a dramatically increased sensitivity to BTH. Extensive cell death is induced by BTH concentrations as low as 1 mM, whereas concentrations of 500 mM BTH had no such effect on tobacco treated in a similar manner. Thus, in some ways, potato SA-signaling resembles certain Arabidopsis SA-signaling mutants more than it does wild-type Arabidopsis. This raises interesting questions about the consequences of high basal levels of SA on defense signaling in some crops.