Exposure to GM plant material containing the proteins encoded by the introduced genes
Expression of the introduced genes for herbicide tolerance and a hybrid breeding system could potentially result in the production of novel toxic or allergenic compounds in the GM canola plants, or alter the expression of endogenous canola proteins. If humans or other organisms were exposed to the resulting compounds through ingestion, contact or inhalation of the GM plant materials, this may give rise to detrimental biochemical or physiological effects on the health of these people or other organisms.
The genes for herbicide tolerance and a hybrid breeding system introduced into the parental GM canola lines were all isolated from common soil bacteria, which are widespread and prevalent in the environment (see Chapter 1, Section 53). In addition, all of the parental GM canola lines are approved for commercial release (under DIR 020/2002 and DIR 021/2002), including for use in stockfeed. The CP4 EPSPS and PAT proteins are also present in GM cotton lines that have been approved for use in stockfeed since 2000 and 2006, respectively (see DIR 023/2002 and DIR 062/2005). Therefore, people and other organisms are already exposed to all of the proteins encoded by the introduced genes.
The toxicity of the parental GM canola lines was assessed in the RARMPs prepared for DIR 020/2002 and DIR 021/2002. This information was summarised and updated in Chapter 1, Section . The GM hybrid canolas proposed for release are not expected to be any more toxic or allergenic than the parental lines, as the same genes will be expressed under the control of the same regulatory elements. The novel proteins and their end products will be the same in the progeny of conventional breeding between the GM canola lines approved under licence DIR 021/2002 and Roundup Ready® canola as in the parental lines. The proteins encoded by the introduced genes are well characterised and are not known to be toxic or allergenic (see Chapter 1, Section 53).
There is no evidence or reasonable expectation that synergistic effects are likely to occur in the hybrid canolas proposed for release or that they would result in new or increased risks relating to toxicity or allergenicity. The GOXv247 and CP4 EPSPS proteins present in Roundup Ready® canola operate through independent biochemical pathways unrelated to those of the BARNASE, BARSTAR or PAT proteins present in InVigor® canola. The goxv247 and cp4 epsps genes are not expected to interact with any of the genes present in InVigor® canola, their proteins or their metabolic pathways.
Analysis of the compositional data for canola seed from InVigor® x Roundup Ready® canola indicates that there are no meaningful differences in the levels of compounds, including natural toxicants, when compared to non-GM canola from the same hybrid background and to other commercial canola varieties. Overall, the agronomic characteristics of InVigor® x Roundup Ready® canola are comparable to their commercial MS8 x RF3 counterparts. These results indirectly support the lack of any synergistic effects in hybrids resulting from conventional breeding between InVigor® canola lines and Roundup Ready® canola.
FSANZ has approved the use of food derived from GM InVigor® canola and GM Roundup Ready® canola for human consumption (ANZFA 2000; ANZFA 2001b). These approvals also cover GM InVigor® x Roundup Ready® canola.
Conclusion: The potential for allergic reactions in people, or toxicity in people and other organisms as a result of exposure to GM plant materials containing the proteins encoded by the introduced genes is not identified as a risk that could be greater than negligible. Therefore, it does not warrant further detailed assessment.
The potential for spread and persistence of the GM canola in the environment
This section addresses the question of whether or not the proposed dealings with the GMOs may lead to harm to human health and safety or the environment as a result of an increased potential for spread and/or persistence due to the genetic modification.
All plants have the potential to lead to harm in certain environments. Harms that may arise from a certain plant species in a particular environment include:
adverse effects on the health of people and/or animals
reduction in the establishment, yield and/or quality of desired plants
restriction in the physical movement of people, animals, vehicles, machinery and/or water
adverse effects on environmental health, such as adverse changes to strata levels, nutrient levels, fire regime, soil salinity, soil stability, or by providing food and/or shelter to pests, pathogens and/or diseases.
For the purpose of this document, plant species causing significant levels of one or more of these harms are called ‘weeds’. A plant species may be weedy in one or more land uses, such as dryland cropping or nature conservation.
Characteristics that influence the spread (dispersal of the plant or its genetic material) and persistence (establishment, survival and reproduction) of a plant species impact on the degree of its invasiveness. These characteristics include the ability to establish in competition with other plants, to tolerate standard weed management practices, to reproduce quickly, prolifically and asexually as well as sexually, and to be dispersed over long distances by natural and/or human means. The degree of invasiveness of a plant species in a particular environment gives an indication of the likelihood of its weediness in that environment. In addition to local experience, a history of weediness overseas can be used as an indicator for weediness in Australia.
Baseline information on the weediness of canola, including factors limiting the spread and persistence of non-GM canola plants, is given in The Biology of Brassica napus L. (canola) (OGTR 2011). In summary, canola is considered a major weed in agricultural ecosystems in Australia (Groves et al. 2003). Surveys have shown that canola occurs as a volunteer weed in up to 10% of cereal crops in southern Australia (Lemerle et al. 1996). However, canola is not considered a significant weed, nor invasive of natural undisturbed habitats in Australia (Dignam 2001; Groves et al. 2003). The weediness of the parental GM canola lines was assessed in the RARMPs prepared for DIR 020/2002 and DIR 021/2002. This information was summarised and updated in Chapter 1, Section 137.
Scenarios relating to altered spread and persistence of the GM canola, compared to non-GM canola, include expression of the introduced genes for herbicide tolerance and a hybrid breeding system increasing the invasiveness of the GM canola.
