ROLE OF INDUCED SYSTEMIC RESISTANCE IN THE BIOCONTROL OF PLANT DISEASES BY FUSARIUM SPP.

Authors: Larkin, Robert - Bob; Fravel, Deborah

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: NA.

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.