Ecological effects of plant resistance traits on above-ground non-target organisms in different genotypes of Brassica and Arabidopsis
11 / 2007 - 10 / 2011
In this research programme we take a multidisciplinary and integrated approach to develop an ecology-based evaluation tool for regulators that can be used to assess the non-target effects of GM-crops under field conditions. We address a combination of two plant traits that can be modified by GM: increased direct resistance against insect pests and increased effectiveness of biological control. GM-crops with increased resistance have been developed previously, although the majority rely on Bt genes only. Increased effectiveness of biological control is a novel trait that has recently been shown to be amenable for GM.
Our multidisciplinary programme involves five steps.
Step 1: Selection of non-target organisms. We will select four to six relevant non-target organisms, both for aboveground and belowground interactions with the ecology-based method of Scholte & Dicke (2005).
Step 2: Assessing baseline effects of direct and indirect resistance traits. The effects of different genotypes on the performance of the selected non-target organisms will be investigated for (a) non-transgenic cabbage (Brassica oleracea) cultivars that have previously been characterized as having either a strong direct resistance and weak indirect resistance or a strong indirect resistance and a weak direct resistance (Poelman et al. unpublished) and (b) non-transgenic Arabidopsis thaliana ecotypes that vary in direct resistance and/or indirect resistance.
Step 3: Assessing transgene effects. For Arabidopsis, transgenic lines of ecotype Columbia are available already and can be used from the start of the project. New transgenic lines will be made to obtain the desired traits and combinations of traits in different Arabidopsis ecotypes to investigate the effect of the genetic background on non-target effects. The cabbage varieties and Arabidopsis ecotypes and transgenic lines will also be characterised for metabolite composition and gene expression profiles in shoots as well as roots. Comparison of baseline effects of non-transgenic Arabidopsis ecotypes with transgenic Arabidopsis is used to assess whether transgenic effects exceed baseline effects.
Step 4: Combination and integration of all the datasets and statistical analysis.
Step 5: Development and refinement of protocol. The experimental data of the 3 projects will be integrated to develop a protocol for environmental risk assessment (ERA) that addresses the effects of GM-crops in conjunction to baseline information. Field and greenhouse data will be compared to assess the validity of using greenhouse data for ERA.