Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2005
Publication Date: 6/15/2005
Citation: Bacetty, A.A., Snook, M.E., Glenn, A.E., Noe, J., Bacon, C.W. 2005. Correlation of endopyte-infected tall fescue root extract fractions with pathogenic nematode activity measured in an in vitro system [abstract]. Phytopathology. 95(6):S5.
Technical Abstract: Root exudates contain hydrophobic and hydrophilic substances released into soils by healthy intact roots and include such classes of compounds as organic acids, peptides, amino acids, sugars, phenols, and other miscellaneous compounds. The roots of grasses, tall fescue in particular, are noted producers of exudates that are speculated to be stimulatory, inhibitory, or inactive relative to competing organisms. Phenolic compounds are deterrents of several soil pathogens and invertebrate pests. Phenolic acids are considered to be biologically active in preventing nematode infestations. Therefore they are candidate compounds potentially involved in resistant or tolerant expressions to nematodes capable of parasitizing tall fescue. The fungal endophyte Neotyphodium coenophialum, associated with tall fescue, produces various secondary metabolites that are potentially toxic to nematodes. HPLC analysis and utilizing UV mass spectrometry of root extracts revealed the presence of polyphenolics that were identified as chlorogenic and di-caffeoylquinic acids. A nematode in vitro assay system reveated that methanolic root extracts and subfractions of N. coenophialum infected tall fescue roots exhibited adverse effects of Prafylenchus scribneri activity while non-infected root extracts did not show any signs of adverse activity on this nematode.