ARS | Publication request: Chemical ecology and isolation of biologically active compounds from parasitic nematodes

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 6, 2011
Publication Date: N/A

Technical Abstract: Root knot nematodes (Meloidogyne spp) are possibly the economically most important and best-studied species of plant parasitic nematodes. However, for Meloidogyne spp and the intensely studied nematode, Caenorhabditis elegans, very little is known about signaling within and in-between species. It has been reported that Meloidogyne species prefer uninfected over infected roots when given a choice. However, the nature of this signal is unknown. When studying C. elegans behavior, we discovered the composition and release of nematode produced small signaling compounds to be tightly correlated with environmental conditions such as crowding and food availability. These signals lead to transition into and out of the dauer stage, which is equivalent to infective juvenile stage of plant parasitic nematodes. We are taking two approaches to identify chemical cues mediating host attraction and avoidance: First, by collecting and bioassaying of volatile cues from Meloidogyne incognita infected and uninfected tomato roots, second, by collecting and bioassaying water soluble cues from exudates and root extracts of plants infected with nematodes and from healthy roots. The metabolites from infected roots and root exudates are fractionated by various chromatographic methods and tested for biological activity. Results from the second approach will be presented.