The Office of the Gene Technology Regulator (OGTR) has clarified the status of organisms modified using the latest gene technologies.

The review focused on gene editing and ribonucleic acid interference (RNAi) gene silencing techniques and identified instances when these technologies do not require regulation under GM protocols starting from 8 October, 2019.

Regulatory restrictions will remain in place for some instances of these new technologies - including methods important to plant breeding - and for organisms developed using older genetic engineering methods.

The review focused on gene editing and RNAi gene silencing technologies and identified instances when these technologies do not require regulation under GM protocols starting on 8 October, 2019

RNAi technology is based on a plant's own defences against viruses and is used to silence plant genes.

The technique uses a small double stranded RNA molecule (to simulate a virus), with the molecule designed to have affinity for the messenger RNA produced by a targeted plant gene.

The affinity leads to the RNAs interacting, creating a molecular structure that the plant cell then neutralises.

This effectively silences gene expression of the targeted gene in the process (just as it would an invading virus).

Useful to plant breeding is a form of RNAi that involves introducing DNA into the plant genome that expresses the silencing RNA.

The trait associated with the silenced gene can then be stably inherited so that the trait can be incorporated into new crop varieties.

However, it is precisely this form of RNAi that remains subject to GM regulations.

Not considered GM is the use of RNAi formulated, for example, as a bioclay that can be sprayed onto a developing crop in the form of herbicide and pesticide formulations to help deal with chemical resistance or extend the life of existing chemistries.

Gene editing

Gene editing, too, has instances where it is classified as non-GM, but other variants are scheduled to be regulated as producing GMOs.

The regulatory review split gene editing into three categories: SDN-1 (site-directed nuclease technique 1), SDN-2, and ODM (oligo-directed mutagenesis technique).

Organisms modified using SDN-1 had a break introduced to a targeted DNA sequence in their genome, which was then repaired using the cell's natural DNA repair mechanisms.

The OGTR found that the changes possible with SDN-1 technology fall in the same range as mutations that occur naturally, they are not detectable and pose no additional risks.

As such, SDN-1 is to be excluded from regulation under the recommended amendments and results in plants that will not be listed as GMOs.

Importantly, valuable traits produced using RNAi technology can be replicated using SDN-1 style gene editing, thereby allowing the grain industry to benefit from these traits in new varieties without incurring the $20-40 million price tag associated with GMOs.

The remaining gene editing categories - which use introduced DNA template to guide changes to an organism's genome - would be classified as GM.

The OGTR acknowledged that modifications obtained by SDN-2 and ODM can be in the same range as natural mutations, but found that they can also extend beyond that range to potentially pose novel risks in some types of organisms.

The OGTR reported: "Within the current policy settings, regulating all organisms modified using SDN-2 and ODM is the only approach that would allow regulatory oversight of those organisms potentially posing novel risks."

It also stated that agricultural industry groups, including exporters, strongly supported the exclusion of SDN-1 from GM regulation.

The US, Brazil, Argentina and Chile have made similar exclusions and Japan is proposing to do the same, which brings trade partners in alignment.

Implications for industry

Organisations working with GMOs are cautioned, however, to continue complying with the current Gene Technology Regulations until the majority of amendments commence in October.

In the meantime, the recommended amendments to the Gene Technology Regulations 2001 are being presented to the Legislative and Governance Forum on Gene Technology for agreement as the final stage of an extensive technical review process.

The amendments are considered commensurate with risk and are designed to impose regulatory burden only when needed to protect human health and the safety or the environment.

More information: Office of the Gene Technology Regulator, ogtr@health.gov.au