Glyphosate suppression of an elicited defense response: Increased susceptibility of cassia obtusifolia to a mycoherbicide

Amir Sharon, Ziva Amsellem, Jonathan Gressel

Research output: Contribution to journalArticlepeer-review

Abstract

The major effort in developing pathogenic fungi into potential mycoherbicides is aimed at increasing fungal virulence to weeds without affecting crop selectivity. Specific suppression of biosynthesis of a phytoalexin derived from the shikimate pathway in Cassia obtusifolia L. by a sublethal dose (50 micromolar) of glyphosate increased susceptibility to the mycoherbicide Atternaria cassiae Jurair & Khan. Glyphosate applied with conidia suppressed phytoalexin synthesis beginning at 12 hours, but not an earlier period 8 to 10 hours after inoculation. The phytoalexin synthesis elicited by fungal inoculation was also suppressed by darkness. The magnitudes of virulence of the mycoherbicide in the dark or with glyphosate in the light were both higher than after inoculation in the light with the same concentration of conidia in the absence of glyphosate. Five times less inoculum was needed to cause disease symptoms when applied with glyphosate than without. Glyphosate did not render A. cassiae virulent on soybean (Glycine max), a crop related to the host. These results suggest that a specific inhibition of a weed's elicited defense response can be a safe way to enhance virulence and improve the efficacy of the mycoherbicide.

Original languageEnglish
Pages (from-to)654-659
Number of pages6
JournalPlant Physiology
Volume98
Issue number2
DOIs
StatePublished - 1992
Externally publishedYes

Fingerprint

Dive into the research topics of 'Glyphosate suppression of an elicited defense response: Increased susceptibility of cassia obtusifolia to a mycoherbicide'. Together they form a unique fingerprint.

Cite this