Friday, April 12, 2024

GMO clover trial pricks methane bubble

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There is a corner of a foreign field that is pretty much New Zealand-developed gene-edited pasture.
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New Zealand farmers are not alone in facing the challenge of striving for value while mitigating their environmental footprint. Senior reporter Richard Rennie is in Australia to find out how our neighbours are approaching the issues of gene technology, carbon farming and sustainability.

On an anonymous, remote, windblown paddock in southwestern Victoria grows what may become the first commercially released gene-modified clover crop – one with its roots firmly in GMO-free New Zealand.

The clover is based off a NZ cultivar and its development is part of a joint venture between AgResearch’s commercial arm Grasslanz and PGG Wrightson Seeds, part of the DLF Group.

The version being trialled kicked off over 10 years ago when researchers inserted a gene from the closely related hare’s foot clover. This switched on an existing pathway in the plant so condensed tannin was produced in the leaves, rather than just the flowers.  

The goal was to deliver farmers a clover with lower bloat risk and – equally importantly for the industry – a clover option that results in lower methane emissions when eaten by livestock.

Kiwi-born plant breeder Matt Francis oversees the contained field trial in Australia, which is now well into its second year, with previous field trials run over three years in the United States. 

“That gene has been about allowing the plant to express high levels of condensed tannins in its leaves. 

“When you insert that gene there is a bit of a trade-off in production or yield. The breeding focus has been to bump up the level of condensed tannins to an acceptable level and to be able to breed for vigour so the plants will be robust, and will survive,” he said.

In the early stages of trial work back in 2018, he said, the plants lacked vigour, but conventional selective breeding since for the high tannin trait and plant vigour has closed the gap significantly.

“We are now up to the level of a commercial cultivar for production.”  

Estimates are methane emissions could come down by as much as 20%, and possibly eliminate bloat risk.

The end of the lengthy development period is closing in as the breeders sort out the best-performing 2500 seedlings from the latest generation, which will ultimately be used to produce seed for animal feed trials, possibly in New South Wales.

For Francis and agronomist Liz Barr, managing and overseeing the project is a big part of their job descriptions, where Francis is also responsible for overseeing PGW Seeds lucerne breeding.

For him the high expressed tannins project represents a tough gig in the business of plant breeding.

“There can be a number of aspects of plant production affected when you modify a species. 

“Condensed tannin production is one of the more challenging traits to work on with gene modification, although we have not noticed any loss in seed production, which can occur.”

Barr is required under Australia’s genetic technology regulations to file a monthly report, ensure there are no crop outbreaks from the containment zone, and to dispose of all grass and clover clippings by burning after mowing around the area’s buffer zone.

“And once a year we will have a visit from the OGTR [Office of the Genetic Technology Regulator].”

Another project also being run in Victoria with Grasslanz and PGG Wrightson Seeds involves gene-edited endophytes in ryegrass, where the function of a gene has been stopped without introducing any foreign DNA.   

The targeted gene-editing technology CRISPR has been used to modify the ryegrass endophytes to deliver better animal health outcomes by removing the expression of toxins that can produce problems with heat stress and staggers in livestock.

These, too, are well advanced and destined for widespread agronomic trials across Australia this year.

Grasslanz CEO John Caradus said the gene-edited and GM field work in Australia presents a far more viable option to the NZ option, where the regulatory process is challenging. Gaining approval for such field trials in NZ has not been attempted for over a decade as a result.

He, like many in the Crown Research sector, has been calling for another look at the gene technology regulations, something the new government has promised it will undertake.

Negative feedback on the Australian trials had been near zero and the site is not subject to overly restrictive containment demands, with mesh type containment housing to keep pollinating insects out.

Caradus is hoping that any review here will result in the NZ government taking a step back and seeing that systems globally, including Australia’s, may enable NZ to explore the benefits that could accrue from the technology. 

He particularly favours the Australian and Canadian systems that focus on research and trial works’ outcomes, rather than just the process.

“I have been impressed with the OGTR. They have been and inspected the sites and been engaged right throughout the whole activity and given good, timely guidance.”

He said he has enjoyed the same with NZ’s Environmental Protection Authority.

“But the problem in NZ are the regulatory rules that they have to work with.”

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