Farm Ireland
Independent.ie

Wednesday 19 December 2018

Irish farmers miss out on gene editing potential

It can take years off developing new breeds of crops, but a recent European Court of Justice ruling means innovative gene editing is restricted here

Jennifer Doudna, inventor of the revolutionary gene-editing tool CRISPR photographed in the Li Ka Shing Center on the Campus of the University of California, Berkeley. MPhoto: Nick Otto For The Washington Post via Getty Images
Jennifer Doudna, inventor of the revolutionary gene-editing tool CRISPR photographed in the Li Ka Shing Center on the Campus of the University of California, Berkeley. MPhoto: Nick Otto For The Washington Post via Getty Images

Anthony King

Gene editing is exciting crop scientists and breeders. It allows the DNA of a crop to be precisely tweaked to improve them. Enthusiasm is mounting around its potential to boost resistance to pests and diseases in crops.

Irish farmers, however, could miss out because of a European Court of Justice ruling earlier this summer.

Breeding a new variety of potato usually takes 12 years with traditional methods, but gene editing can do this in 2 or 3 years, said Dr Ewen Mullins, crop scientist at Teagasc.

The most popular technique is called Crispr, which spawns all sorts of catchy headlines about Crispr vegetables. Remarkably, Crispr gene editing was first used on plants only in 2013.

Gene editing is different from the older, controversial technique of genetic modification, or GMOs, which usually introduce genes from other organisms. Instead, Crispr gene edits only DNA within a crop.

Invented by Jennifer Doudna, the power of Crispr for agriculture was first shown in a gene edit of mushrooms by scientists at the University of Pennsylvania in Pittsburgh. They switched off a single gene. This stopped the mushrooms from bruising easily and extended their shelf life.

An embryo collection in gene editing
An embryo collection in gene editing

"Published studies show you can generate resistant strains of wheat with a single edit. You can generate varieties that would really help farmers," said Dr Mullins.

"However, the European policy right now is for gene edited varieties to be labelled as GMOs, which in effect has put a pause on research that was building up."

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European breeders got a shock in July when the European Court of Justice ruled that gene edited crops must be regulated as GMOs. While gene editing changes a plant's own genes, the older technique introduced genes from other organisms, including bacteria, so was viewed by scientists very differently.

"Plant researchers and breeders around the world were surprised by the ruling," said Dr Mullins. "The advocate general for the court had published his preliminary findings, which suggested that the ruling would regard gene editing as the same as other forms of mutagenesis."

Mutagenesis has been essential to improve crops since the 1950s. It involves hitting seeds with harsh chemicals or radiation to introduce changes to the DNA of the resulting plant, which will have variations that typically result in improved traits, such as resistant to disease.

"If you wanted to breed resistance to stem rot in oil seed rape, you treat thousands of seeds with nuclear radiation. This has a huge impact on their DNA. Then you plant them in the field and discard those that are still susceptible," Dr Mullins explained.

Close-up of Septoria infected wheat leaf
Close-up of Septoria infected wheat leaf

"But the problem is you have to evaluate thousands of plants in the hope of identifying a few good ones. The process changes many genes and traits, so the plants could also have multiple traits that you don't want such as reduced yield or a softer stem."

These side effects must be bred out of the plants, one reason why breeding new varieties takes so long. It is estimated that 70pc of all cereal and rice varieties in the world are derived from mutagenesis programmes, usually with chemicals or radiation.

Gene editing is almost like laser surgery in comparison to this blind bludgeoning. This is why seed breeders were stunned: traditional, non-targeted mutant-causing techniques are allowed in Europe, yet the ECJ decided that gene editing should be scrutinised like GMOs.

To be clear, GMO crops are not banned in Europe, but the regulatory rules have stifled them just the same. Just a few thousand hectares of GM maize are planted in Spain and Portugal.

Meanwhile, the US says it will regulate gene editing like regular plant breeding. South America is expected to follow suit. Australia and Japan have made similar decisions, and China is already investing hugely in gene editing technology.

This will "almost certainly impede innovation in plant breeding and agricultural productivity," said Dr Johnathan Napier, plant scientist at Rothamsted Research in the UK.

"The ECJ ruling puts Europe's farmer's at a disadvantage compared to those nations which have embraced this innovative technology."

Others agree this will be bad for European farmers.

"You are likely to see markets outside of Europe develop and plant new edited varieties of crops, fruits, vegetables and ornamentals. This will allow for reduced pesticide and fertiliser use and more environmentally sustainable yield increases," Dr Mullins predicted.

"Regrettably, Europe will be placed at a competitive disadvantage."

Dr Mullins also pointed to climate change, highlighted by our recent erratic summer, as another reason why more resistance needs to be bred into our cropping system. European legislation is also pulling back on the list of agrichemicals that farmers can use.

"We need as many breeding tools as possible to give farmers resilient cropping regimes, so that the profitability of their system is maintained," said Dr Mullins.

Dr Napier said, using gene editing, work is underway to make bananas less prone to browning, coffee beans that are decaffeinated, peanuts that don't contain allergenic proteins and crops better able to withstand pathogens.

Ironically, Europe may well import gene edited crops, as it does with GMO soya bean for animal feed.

The ECJ decision may well be a thorn in the side of Irish and European regulators after Brexit, depending on the outcome of the negotiations.

The National Farmers' Union and the Ministry of Agriculture in the UK have indicated that they would consider gene editing as just another form of mutagenesis.

This is where the rubber hits the road in terms of regulatory problems for the European Commission. Gene editing introduces no new genes. It is therefore almost impossible to spot.

"When you have a classical GMO, so genes from another species in a crop, that is like a big lighthouse. It is easy to identify using molecular genetics.

"With editing, you cannot identify where the edit was made. These sorts of changes happen in nature and through normal breeding all the time," said Dr Mullins.

After fuming about the ECJ decision, plant scientists now say that European law needs to be updated to allow for gene editing, which was never thought of when the regulations where put in place in 2001 (Directive 2001/18/EC).

Breeding companies in Europe, on the other hand, have moved much of their R&D overseas, and start-ups interested in gene editing of crops are predicted now to exit Europe.

"As I understand it, the European directive [on GMOs] would have to be changed and that involves the Commission going to the European Parliament and a lot of debate and politic before the law could be changed," said Dr Mullins.

GM potatoes resist late blight

Potatoes in Ireland are typically sprayed with fungicide 10 to 12 times per year, due to the constant threat of late blight.

Late blight disease is controlled well, but this is expensive and there is an environmental impact.

"We've never met a farmer that likes to spray. It's a necessary part of the business. If there is an alternative, they are interested," said Dr Ewen Mullins, crop scientist at Teagasc.

Teagasc carried out a study of a GM potato engineered to be resistant to late blight.

This involved cutting a gene from a wild potato species and inserting it into a conventional potato.

"Many wild potatoes have strong resistance to late blight, but also many have traits we don't want," said Dr Mullins.

"Scientists in the Netherlands developed the GM potato line and through the EU funded AMIGA project we were able to examine the agri-environmental impact of this novel potato variety."

The GM potato reduced the environmental impact of potato production by up to 95pc.

Late blight strains have the potential to overcome the genetic resistance, but more modern gene editing techniques can rapidly generate new crop varieties.

"It is much faster than traditional breeding. Breeding a new potato variety can take 12 to 13 years. With this approach, this can be reduced to 2-3 years," said Dr Mullins.

A recent decision by the European Court of Justice has, however, taken the option of gene-edited crops off the table for European seed companies, and likely European farmers too.

Lab research using gene editing will continue in Europe, but trialling new gene edited crops in the field is likely to hit the buffers.

"We had editing projects in play. Our goal at Teagasc is to deliver solutions through practice. The customer is the man or woman driving the tractor," said Dr Mullins, adding that breeding programmes will continue to use gene editing to improve genetic understanding of crop varieties.

"There was overwhelming evidence that gene editing was more precise and faster. So it was a surprising decision" he said.

"But is it a negative? It doesn't much matter [at Teagasc], because the law is the law and we have to get on with it."

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