ACRE Advice

Advice on a notification for marketing of herbicide tolerant GM oilseed rape

Advice of the Advisory Committee on Releases to the Environment (ACRE) under S.124 of the Environmental Protection Act 1990 (Part VI) to the Secretary of State for Environment, Food and Rural Affairs, Scottish Ministers, Ministers of the Welsh Assembly Government and the Department of Environment (Northern Ireland).

Comment

On the basis of the information provided regarding characterisation and risk assessment of GT73 ACRE were content with this notification for genetically modified oilseed rape in terms of risk to human health and the environment. However, the Committee would like to comment that they were disappointed with the presentation of this dossier which was difficult to navigate. In addition ACRE commented that as the dossier was submitted in 1998 the supporting scientific literature was now a number of years old. However, the Committee agreed that this did not significantly affect the risk assessment of GT73.

Genetic modification and molecular characterisation

ACRE noted that the data relating to molecular characterisation of GT73 was poorly presented, in particular the quality of reproduction of the Southern blots was criticised. On a specific point, on several occasions in the dossier Monsanto refer to restriction enzyme digests with EcoR1 which they state does not cut inside plasmid PV-BNGT04 (e.g. part D, 2, d). EcoR1 does in fact cut within this plasmid. It would be appreciated if Monsanto could clarify this.

The genetically modified oilseed rape line GT73 was created by Agrobacterium tumefaciens mediated transformation. The cp4epsps and goxv247 genes were inserted into the plant genome resulting in tolerance of the GM oilseed rape to glyphosate herbicides. Southern blot and PCR analysis was performed to demonstrate that the plasmid DNA is inserted at a single locus in the nuclear chromosome and that vector backbone sequences are absent from line GT73. On the basis of the data supplied by the applicant, it is likely that a single copy insert is present in line GT73 and that vector backbone sequences are most likely absent.

No information is provided in the dossier regarding the location in the oilseed rape genome where the genetic material is inserted. ACRE acknowledge that, on the basis of the animal feed data provided, that GT73 oilseed rape is substantially equivalent to its non-GM counterparts hence, insertion of the additional genetic material does not affect the phenotype of GT73 (with the exception of glyphosate tolerance) and therefore has not disrupted a gene that affects growth and agronomy of GT73. However, ACRE consider it important to know and understand the nature and location of the insertion of the genetic material, hence, request that the notifier provide this information, specifically sequence information of the flanking regions of the inserted genetic material. This should include details of any genes disrupted as a result of the insertion and their possible phenotypic effects on the GM plant.

Animal feed safety

ACRE asked the Advisory Committee on Animal Feedingstuffs (ACAF) to assess GT73 from the perspective of animal feed safety. ACAF, like ACRE, noted that the dossier was poorly presented and randomly organised, making it difficult to find the relevant data. ACAF considered the dossier with respect to the safety of the expressed proteins, safety of rapeseed GT73 and animal studies.

Safety of the expressed CP4 EPSPS and GOX proteins was assessed by over expression in E coli , extraction and tests in simulated gut environments and in acute toxicity studies in mice. The CP4 EPSPS protein has been widely studied in previous constructs, on the basis of this and the evidence presented by Monsanto, ACAF conclude that this protein is safe for use. In comparison the GOX protein has not undergone the same level of scrutiny. The evidence provided to ACAF concluded that the GOX protein is degraded in simulated gut environments, activity is lost at temperatures greater than 60(C and when fed to mice in an acute toxicity study no adverse responses were noted. On the basis of this information ACAF were content with the safety and toxicity analysis of the GOX protein.

ACAF considered the safety of GT73 oilseed rape on the basis of comparative compositional data. The data provided generally showed no significant differences between GT73 and the parental Westar variety. Although none of the data provided would appear to show cause for concern, ACAF is reluctant to draw conclusions on the composition equivalence of GT73 to its parental Westar control on the basis of the available information. ACAF noted the variation in the concentration of alkyl glucosinolates in samples of GT73 compared to the Westar parental control. However, all values were well below the levels set for alkyl glucosinolates hence, this variation was not considered a safety issue. ACAF advised that a possible course of action could be to require regular analysis of imported GT73 alkyl glucosinolates concentrations to ensure they do not exceed the limits set by European legislation as part of the post-market monitoring plan.

ACAF considered the animal feed studies provided in the dossier. No significant differences in growth were observed between rats fed GT73 or Westar parental variety oilseed rape. However, the relative liver weights for the rats fed 15% processed GT73 oilseed rape were found to be significantly higher than controls. This was attributed to higher glucosinolate concentration in the GM diets compared to the corresponding control diets. This adverse effect was reportedly not observed in a subsequent rat experiment, although ACAF have not seen the relevant data.

Although, on the basis of the summary compositional data provided in this dossier ACAF would expect GT73 oilseed rape to behave as any other oilseed rape variety, they could not reach this conclusion without seeing further information.

Post market monitoring plan

The post market monitoring plan is a new requirement under Directive 2001/18/EC. The plan provided by the notifier is brief and limited. On the basis of the risk assessment for GT73 Monsanto do not propose to carry out any case-specific monitoring. ACRE agree with this conclusion as the risk assessment does not identify any risks in relation to human health or the environment from the use of GT73 oilseed rape as defined in the notification (i.e. for import and processing).

Directive 2001/18/EC places a requirement to provide a monitoring plan for the occurrence of adverse effects not anticipated in the environmental risk assessment. ACRE consider that the proposal in response to this requirement put forward by the notifier is unsatisfactory. In particular the plan does not take into account monitoring of the occurrence and effects of seed spill during transportation and processing of the oilseed rape seed. Based on current experience regarding movement of non-GM oilseed rape in the UK seed spill is likely to occur and will result in the survival and establishment of feral oilseed rape populations and their hybridisation with crop and other feral populations. It is accepted that the risk of harm to human health and the environment from seed spill is low, however there is an issue, in the UK, regarding the segregation of transgenic and non-transgenic material. Hence, ACRE request that Monsanto review their monitoring plan taking into account methods of monitoring and reporting seed spill, incorporating a proposal as to how seed spill may be controlled. It should also include plans for monitoring and controlling establishment of feral populations as a result of seed spill.