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United States Department of Agriculture

Agricultural Research Service

Title: Role of Induced Systemic Resistance in the Biocontrol of Plant Diseases by Fusarium Spp.

item Larkin, Robert
item Fravel, Deborah

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 1997
Publication Date: N/A

Technical Abstract: Induced systemic resistance (ISR), which refers to the activation of plant defence mechanisms by inducing agents, is involved in the mechanisms of action of several biocontrol agents, including certain rhizobacteria, fungi, and pathogenic and nonpathogenic Fusarium spp. Dose-response relationships of three nonpathogenic Fusarium isolates (CS-20, CS-1, and Fo47) that effectively control Fusarium wilt diseases of several crops and differ in their mechanisms of action indicated that isolates CS-20 and CS-1, which function primarily by ISR, were effective at much lower inoculum densities than Fo47, which functions primarily by competition, indicating that ISR was a more efficient mechanism than competition. ISR may also control multiple pathogens. Plant physiological responses observed following plant inoculation with Fusarium biocontrol isolates included increased activity of glycosidase and oxidative enzymes, and increased synthesis of phenols. Although much more information is needed regarding its nature, physiology, and applications, ISR has much potential for improving biocontrol efficacy.

Last Modified: 4/22/2015
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