At the Gardens Point campus of the Queensland University of Technology, there is a room hidden atop an old, brick building, where scientists meet and conduct research unlike anywhere in the world. Their goal: to sure up the fate of one of the world’s largest crops – bananas.
Professor James Dale AC is an agricultural scientist and distinguished professor in the Faculty of Science School of Biology & Environmental Science at QUT. He doesn’t teach, but for the past 10 years, he has led a team of world-leading scientific researchers. Their field of research – genetically modified banana crops – is gaining global importance in the wake of a potentially devastating banana pandemic threatening crops worldwide.
Dale cuts a slight frame against his imposing, almost primeval office in one of the University’s oldest buildings. His desktop, however, is lined with keyboards and computer screens, facing the desk of Joanne Simpkins, the QUT Bananas project manager with whom Dale shares his office.
‘This building is really flash,’ Dale says, perhaps recognising the irony of a cutting-edge research facility in an old brick building.
But Dale’s research is anything but gimmicky.
‘Bananas are one of the world’s top ten food crops,’ Dale says. ‘Wheat, maize, rice, potato, Kasava, then bananas, soybeans, sweet potato, sorghum. Depends how you count sugar cane I suppose.’
Originating in South East Asia and New Guinea, the banana crop is a staple food across Asia and Africa. The crop’s high starch content and ease of tropical cultivation makes it a key foodstuff for some of the world’s most impoverished regions, providing accessible, reliable, and healthy food.
‘In Uganda, they cook raw bananas while they’re hard,’ Dale says. ‘The bananas are steamed for three-to-four hours, then mashed. The dish, “Matooke,” is a staple of Uganda, and across East Africa, bananas are a massive crop in the region.’
When it comes to bananas, Dale knows what he’s talking about, and after 30 years of working on the crop, the professor has become concerned.
Dale and his team have for the past decade focused their research on the emergence of a fungus called Tropical Race 4, and the development of genetically modified bananas able to resist the fungus. In a post-pandemic world, we think of deadly diseases as spreading rapidly through regions and communities, so the slow-moving fungus has at least left time on Dale’s side. But in agriculture, a little fungus is a big deal.
‘Once it gets in the soil, it’s impossible to remove,’ Dale says.
However, the severity of scale for a banana plague isn’t comparable to COVID-19. Instead, Dale invokes the Potato Blight, a fungus that gripped the northern hemisphere in the mid-1800s. Due to the regressive British Government export and land-use policies of the time, the Blight became concentrated on Ireland, where over a million people starved to death in a single year. According to Dale, this could be a microcosm of a world in a banana plague.
‘There is a very narrow genetic base of food crops that we eat,’ Dale explains. ‘Industrial agriculture is based around monocultures, wherein a single cultivar is closely replicated or cloned to maximise output. That’s why the Irish Blight eliminated a single potato crop across Ireland. No diversity is bad for immunity.’
And when it comes to farming, bananas are a problematically un-diverse crop.
‘There are about a thousand varieties,’ Dale says of banana species. ‘But globally, the Cavendish banana makes up about 50% of all variety.’
Cavendish bananas and their variants are the bananas you get from the store. Unlike their wild counterparts, these bananas don’t go to seed, which is great for consumers – less seed, more banana. But this means that when a new banana tree grows from the base of an old one – a process known as budding – the new tree is an exact genetic replica of the old one.
All Cavendish bananas are clones.
These clones didn’t always make up such a large portion of the world’s bananas. Until the 1950s, the Gros Michel banana was favoured by agriculturalists because its thicker peel made the crop resistant to bruising in transit. That was before Tropical Race 1, often referred to as Panama disease made its production unviable.
‘They were clones, and they weren’t resistant to the fungus,’ Dale says. ‘Cavendish has taken over precisely because it is resistant to Tropical Race 1.
Tropical Race 4, now present in South America, Asia, Australia, Sri Lanka, and Europe, is a blight for almost every species of banana, including the Cavendish. But in the wild, uncultivated, seeded banana plants of the world, some diversity remains.
Dale and his team identified a south-east Asian banana variant resistant to Tropical Race 4. After identifying the gene resistant to Tropical Race 4, they extracted the gene and inserted it into a Cavendish plant. The gene in question is already present in the Cavendish – the difference is, it isn’t activated.
The team uses CRISPR gene editing to manipulate the DNA of banana plants.
‘Trees have embryos too and we can make them in the lab,’ Dale says. ‘From modifying the embryo, we grow a plant that is a Cavendish in every way except that it is resistant to Tropical Race 4.’
But not everyone is completely sold on the prospect of genetic modification, and so far, no gene-edited crops have been approved in Australia for sale. Synthetic Biologist Dr Artem Anyshchenko warns public uptake of genetically modified organisms is tentative.
‘There are plenty of socio-economic considerations that affect the acceptability of the product,’ Dr Anyshchenko says.
‘There are embedded moral values too. Regardless of those considerations, GMOs are indispensable to the global food supply, not only in the future but also today.’
University of Queensland researcher Dr James Hereward, who studies population genetics to understand agricultural pests, says there is an ongoing review process at Food Standards Australia and New Zealand to establish how to regulate gene-edited crops relative to GMO foods.
‘Gene editing is a very powerful technology that can accelerate efforts to increase production and make crops more resilient to climate change,’ Dr Hereward said.
‘In Australia, gene editing methods that do not introduce any new genetic material are de-regulated by the Office of the Gene Technology Regulator.’
‘In many ways, gene editing is the same as conventional breeding methods that create random changes to the DNA of a crop species by chemical mutagenesis, but they are more precise and targeted.’
This is essentially the technique developed by Dale to activate the resistant gene in the Cavendish, which has since been successfully tested at exposed sites in the Northern Territory. The eventual goal; to provide an alternative to, and potentially replace, Cavendish plantations in Uganda, across Africa, and the world.
And for Dale, this is only the beginning of the positive implications of this research.
‘The Cavendish is high yielding … others are bigger, tougher, tastier, disease resistant… we could potentially identify the relevant genes across these species and improve the output and quality of bananas around the world.
‘Similar opportunities exist too for other crops … citruses like oranges.’
Until the day Dale’s bananas hit the shelves, there is one more major hurdle to clear.
‘They’re tiny,’ Dale laughs. ‘They get to about the size of your pinky at the moment, but they’ll be at the store sometime soon, I hope.’