Does solanoeclepin A act as a host-searching cue for Globodera rostochiensis?

Abstract

Plant-parasitic nematodes often interact with host plants via chemical compounds to optimize the chance of invasion. Previous research suggests that hatching factors may also be involved in host-searching in nematodes. Here we tested whether solanoeclepin A (SEA), a host-derived hatching factor for G. rostochiensis, was utilized as a host-searching cue by second-stage juveniles (J2s). A two-choice bioassay using a rectangular Petri dish containing soil was performed to observe nematode responses. The SEA concentrations tested (0.01, 0.1, 1 and 10 ppb) were known to be suitable for hatching and were assumed to correlate to the concentrations around cysts in soil. When J2s were placed between soil moistened with potato root diffusate (known to attract G. rostochiensis J2s) and water-moistened soil, a significantly larger number of J2s chose diffusate-treated soil. However, J2s did not discriminate between soil treated with SEA and soil treated with solvent only. These results suggest that G. rostochiensis J2s do not use SEA as a hostsearching cue.