Finding an acceptable way to sterilise trees
IN THE FIGHT AGAINST WILDING PINES, THE focus is going on finding an acceptable way of modifying trees to stop them producing fertile seeds or cones.
Currently the use of genetic modification (GM or GMO) in trees is not acceptable to a number of organisations in New Zealand, including certifiers FSC and PEFC, and has not yet won government approval. Greenpeace and other environmental groups are vehemently opposed.
But a plant molecular geneticist believes there may be a viable option that is acceptable to officials, which would not threaten New Zealand’s clean and green image.
Dr Glenn Thorlby told the New Zealand Institute of Forestry annual conference in Rotorua last month that gene editing may supply a possible solution to producing sterile plantation trees, such as Douglas-fir and Radiata Pine.
“Editing a gene that is already there means that you are not adding any new genes,” says Dr Thorlby, explaining that this technique is considered non-GMO in many jurisdictions because it can be done without adding any DNA.
He says the changes made through gene editing are the same type as found using traditional mutagenesis, meaning they cannot be distinguished from a natural change.
However, even if the method is ruled acceptable, actually achieving gene editing in a complex organism like a Douglas-fir tree is incredibly difficult, he says.
Dr Thorlby says two projects funded by the Ministry of Business, Innovation and Employment (MBIE) that were begun by Scion scientists last October are aimed at finding bio-technical solutions to the wilding pine problem.
The first project, called ‘Making Wood, Not Love’ is about producing a rapid prototype of a sterile tree using Japanese Red Pine to deliver a proof of concept. It produces cones when only three years old, so changes that have been made can be seen much earlier than with other pine species. And because the project can be carried out inside, any risks are easier to contain than with trees planted outside.
The second, much larger project is called ‘Winning Against Wildings’ and in addition to MBIE funding, it is supported by the NZ Forest Growers Levy. The project looks at all aspects of the fight against the spread of wildings, including control, the natural ecology of wildings, as well as developing sterile trees with a view to commercialising the technology.
Dr Thorlby says that although the projects are only one year old, the Scion teams are already making good progress in developing tissue culture systems that could produce sterile trees. This includes mass propagation of Douglas-fir and testing to see which conifer genes are involved in reproduction and how these can be edited.
The first engineered plants have just been potted and it will be at least three years before scientists can see the first results of their efforts.
The first engineered conifer seedlings being grown by Scion with the aim of producing sterile trees.