The banana is under threat
The world’s most popular banana is under threat from a deadly fungus – but scientists think they might be able to save it through genetic modification. Tropical Race 4 (TR4) kills banana plants by choking off their supply of water and nutrients – first discovered in the 1980s, it has infected crops across the world.
But Australian scientist James Dale is hoping to come to the rescue – with a crop of bananas genetically modified to be resistant to the disease.
TR4 lives in the soil, is resistant to pesticides and, when it gets hold of a banana crop, all but wipes it out. “It looks like somebody’s gone to the plantation with a herbicide,” says plant pathologist Randy Ploetz, who was studying banana diseases when he came across TR4 in 1989.
Two to nine months after being infected, the plant collapses; the soil it grew in, now riddled with the fungus, is henceforth useless for growing the cheap and nutritious fruit.The type of banana which TR4 affects, the Cavendish, makes up 47 per cent of all global banana production and 99 per cent of global banana exports.
The story so far …
It was back in 2004 that Dale, a professor at Queensland University of Technology in Brisbane, isolated a gene called RGA2 from a wild banana called Musa acuminatamalaccensis, an inedible variety naturally resistant to TR4.
But Australian law forbade him from taking TR4-infected soil from the Northern Territory, where the infection was rampant, into Queensland for quarantine reasons. Progress halted until several years later, when a desperate Northern Territory farmer called Robert Borsato, whose farm was overrun with the disease, called Dale for help.
“I told him: ‘we’ve got this possible solution, but we have no idea whether these plants are resistant – would you work with us?’ ” Dale, 68, recalled.“And we went up there and that really was bingo.”
Dale carried out a three-year trial, then published his results in the journal Nature Communications in 2017. Between 67 and 100 per cent of the plants without the resistance gene had been killed or infected with TR4; of the five plant lines with the added RGA2 gene, four had infection rates below 30 per cent, and one line showed no signs of the disease at all.
Dale is now undertaking another study over an area more than ten times larger than the original, and hopes to see the modified Cavendishes on sale by the middle of the next decade. They would be the first genetically modified bananas sold in the world.
Before that can happen, he will also need to apply for a tasting licence – as so far Dale hasn’t eaten a single banana, because the terms of his trial license prohibit anyone from tasting the fruit.
In Australia, experimenting with genetically modified organisms is only allowed under strict conditions, designed to prevent harm to humans and minimise the chance that GM plants will breed with naturally-occurring plants and introduce genetic changes. GM fruit and vegetables have also never been sold in the EU, although they have in the US.
If you’re saving one of humanity’s favourite fruits from extinction – or are otherwise involved in pioneering scientific research – you may be able to get financial help from the government through r&d tax credits. As research and development tax specialists, we can do most of the work on your r&d tax claim for you – so you don’t have to take time away from tasting the fruits of your labour. Have a look at our r&d tax credits calculator or call us at our Manchester office
