Benzyl isothiocyanate affects development, hatching and reproduction of the soybean cyst nematode Heterodera glycines

Abstract

Benzyl isothiocyanate (BITC), prepared in 1% methanol and applied at micro-molar doses, decreased Heterodera glycines infective second-stage juvenile (J2) movement, hatching and reproduction on soybean. Glycine max. Direct exposure of J2 to 30 ßM BITC caused an immediate decrease (17%) in J2 movement relative to 1% methanol controls, and within 3 h exposure eliminated >99% of movement. Continuous exposure of H. glycines eggs to 30 ßU or 60 /xM BITC significantly decreased percentage hatch of J2 measured at 7 days (30 ßU, 15.8 ± 2.4%; 60 ßU, 7.9 ± 2.2%) relative to controls (44.9 ± 4.1%). Control percentage hatch increased between days 7 and 14 (87.5 ± 2.3%), whereas there was no significant increase in hatch after Day 7 in either treatment group. The effect of BITC on hatch was rapid and persistent. Following 4 h exposure of eggs to either 30 ßM or 60 ßM BITC and transfer to water, percentage hatch at Day 14 was 51.3 ± 6.3% and 15.6 ± 1.4%, respectively. Each value was significantly less than the control percentage hatch (96.5 ± 0.2%). The same treatment method also resulted in decreased reproduction. The mean number of cysts per plant harvested 5 weeks after inoculation with control eggs (173.0 ± 12.1) was significantly greater than the numbers from plants inoculated with either 30 ^M (78.9 ± 8.2) or 60 ßM (38.3 ± 4.5) BITC treated eggs. Reduction of hatch and reproduction were strongly correlated, with r^ > 0.60 for both 30 ßM or 60 ßM BITC treatments. The effects of BITC were primarily on the early embryo. The percent of all embryos in the multicellular stage at Day 14 in control eggs was 4.9 ± 0.7%, but increased to 35.1 ± 4.3% (30 ßM) and 56.3 ± 4.5% (60 ßM) in BITC treated eggs. BITC has multiple effects on H. glycines, affecting both infective juvenile movement and embryonic development, and decreasing reproduction.

Nematicidal Activity of the Volatilome of Eruca sativa on Meloidogyne incognita

“…Apart from having nematicidal activity, isothiocyanates and thiocyanates are also general biocides, the activity of which is based on irreversible interactions acting as electrophiles that are subject to nucleophilic attack by cysteine residues in biologically critical proteins. , Moreover, being glucosinolate volatile breakdown products, they could represent good candidates for the control of nematodes as safe fumigants in integrated pest management procedures. Many of these volatiles have been shown to act as attractants for certain insects seeking food or egg-laying sites rather than to possess a direct insecticidal activity. − …”

Targeting internal processes of plant-parasitic nematodes in the pursuit of novel agents for their control

“…Treatment of H. glycines eggs with BITC decreased the percent J2 hatch in a dose dependent manner, and was correlated with subsequent decreases in reproduction on G. max (Wu et al, 2014). The effect on hatch suppression was rapid.…”

“…Benzyl isothiocyanate (BITC), one of the more nematotoxic of the ITC (Buskov et al, 2002;Zasada & Ferris, 2003), was chosen for experimentation. An in vitro behavioural bioassay showed that BITC at concentrations as low as 10 pM , applied directly to hatched J2 of either H. glycines or M. incognita, significantly reduced mobil ity in less than 3 h (Zasada et a l, 2009;Wu et al, 2014). Exposure of M. incognita J2 to 30 /./M BITC for 2 h prior to the inoculation of glasshouse cultures dramatically re duced reproduction on either G. max or Capsicum annuum (Zasada et al, 2009;Masler et a l, 2010).…”

Nematicidal Activity of Cyclopiazonic Acid Derived From Penicillium commune Against Root-Knot Nematodes and Optimization of the Culture Fermentation Process

“…All the experiments were repeated twice with six replicates. The following formula was used to calculate the cumulative percent of egg hatch ( Wu et al, 2014 ):…”