The influence of different nutrient levels on insect‐induced plant volatiles in Bt and conventional oilseed rape plants

Abstract

Transgenic Bt (expressing the cry1Ac endotoxin gene) and conventional oilseed rape plants grown in different soils were used to study nutrient uptake and emission of volatiles after herbivore damage. All plants were greenhouse-grown in soils representing low-, medium- and high-nutrient levels. The concentrations of N, P, K, Mg and Zn were significantly affected by the transgene, while the main effect of soil type appeared in N, P, Ca, Mg, B, Mn and Zn concentrations in the plants. Plants with four to five leaves were infested with the third instar larvae of Bt-susceptible Plutella xylostella for 48 h, and samples of volatiles were collected and analysed. In the first experiment, the soil nutrient level had a significant effect on the emissions of (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, hexyl acetate, (E)-4,8-dimethyl-1,3,7-non-atriene (DMNT), beta-elemene, gamma-bisabolene, alpha-bisabolene and (E)-nerolidol. The induction of these volatiles was significantly higher in infested conventional plants grown at a high-soil nutrient level compared to infested conventional plants at a low-soil nutrient level. In the second experiment, the soil nutrient level had a significant effect on the emissions of (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate and beta-elemene and, again, this was significantly higher in infested conventional plants grown at high-soil nutrient levels in comparison with infested plants at a low-soil nutrient level. In both experiments, the transgene effect was significant on the emissions of DMNT and (E,E)-alpha-farnesene. The differences in emissions between the two separate experiments suggest that growth conditions (particularly daylength) and sampling procedure may affect the ratio of compounds detected in the emission blend, even though the response to herbivory, nutrient availability and the transgene were similar.

Effect of Bt maize on the plant-aphid–parasitoid tritrophic relationships

“…as a mortality factor for cereal aphids, also on maize, cannot be neglected. Differences reported between Bt and non-Bt plants include changes in the blend of plant volatiles emitted (Yan et al 2004;Turlings et al 2005;Dean and De Moraes 2006;Ibrahim et al 2008), the sap amino acid content (Faria et al 2007;Herrero et al 2007) and the honeydew sugar composition (Lawo et al 2009). These potential changes in plant and host quality due to the genetic modification of maize plants could affect the host location process and the growth, development and mortality of aphid parasitoids (Vinson 1976;Oliver et al 2005;Bukovinszky et al 2008).…”

Leaf Volatile Emissions of Betula pendula during Autumn Coloration and Leaf Fall

“…The GLV standard included: cis-3-hexen-1-ol, trans-2-hexenal, 1-hexanol, 1-octen-3-ol, cis-3-hexenyl acetate, 1-chloro octan, nonanal, cis-3-hexenyl butyrate, methyl salicylate, cis-3-hexenyl isovalerate, and cis-3-hexenyl tiglate. All compounds were purchased from Sigma-Aldrich (parent company of Sigma, Aldrich, Fluka and Supelco) except sabinene from CHE-MOS GmbH, trans-β-farnesene and cis-3-hexenyl isovalerate from Bedoukian Research Inc. DMNT was synthesized in-house from commercial citral using methyltriphenylphosphonium bromide and butyl lithium (Ibrahim et al, 2008).…”

Tripartite plant microbe and nutrients interaction in the below ground soil ecosystems

“…Soil abiotic factor are the major players in the tritrophic dynamics through a number of ways. Nutrient availability determines production of signalling molecules (Ibrahim et al,(97)(98)(99)(100)(101)(102)(103)(104)(105)(106)(107) [14] . For instance potassium (K) deficiency has been found to increase jasmonate and glucosinolates signalling molecules (Troufflard et al,172) [33] .…”