Scientifically Speaking | As bananas fall victim to a pandemic, GM comes to the rescue

A fungal disease threatens to wipe out the most popular banana variety. Scientists have created a genetically modified fruit resistant to the fungus

For the first time in gastronomic history, genetically modified bananas will also be available for consumption. Earlier this month, regulators in Australia and New Zealand approved the TR4-resistant strain of the humble and immensely loved fruit for commercial growth. As it turns out, a particularly virulent pandemic affecting bananas is responsible.

People prefer seedless bananas to wild bananas that have seeds, so the bananas we buy are grown from parts of the plant, not from seeds(Pixabay)

In a Scientifically Speaking column I wrote in 2021, I lamented that the Cavendish — the variety which constitutes around 50% of the world’s share of bananas — was imperilled. The Cavendish became the most popular banana worldwide when a fungal disease known as Panama disease wiped out its predecessor, the superior-tasting Gros Michel. The fungal strain responsible for the decimation of the Gros Michel is known as Tropical Race 1.

Now, a virulent form of Panama disease threatens the Cavendish caused by a new strain, Tropical Race 4 (TR4). For the past few decades, TR4 has been spreading around the world. It started in Taiwan, then moved to other parts of Asia and Australia, and later to Africa. More recently, it reached Latin American countries, which are the main suppliers of bananas to Europe and North America.

People prefer seedless bananas to wild bananas that have seeds, so the bananas we buy are grown from parts of the plant, not from seeds. Cavendish bananas, which don't have seeds, are genetically very similar to each other. They all have a faulty gene required for resistance to TR4. This similarity makes them more likely to get afflicted by spreading Panama disease.

In 2021, the outlook was grim, but there was reason for hope. I wrote that several approaches were being tested to save the Cavendish including gene editing to recover the wild form of the gene that makes bananas resistant to TR4. Australian researchers at the time had successfully tested a genetically modified version of the Cavendish that appears to be resistant to TR4.

This banana strain, known as QCAV-4, engineered through years of meticulous research led by Professor James Dale of the Queensland University of Technology, incorporates a gene from a wild banana species with near immunity to TR4. Now, with its approval, a milestone in agricultural biotechnology has been achieved. The approval of QCAV-4 – the world’s first genetically modified banana now sets the stage for approval and wider acceptance of genetically modified variants of other staple crops that are resistant to major diseases.

The Cavendish is safe for now against the devastating impacts of TR4.

Will GM replace the OG?

The modified QCAV-4 banana is not intended to replace the original Cavendish, but to serve as an industry back-up, to be deployed when TR4 spreads more rapidly. The landmark approval of the QCAV-4 banana also paves the way for further innovations in gene-edited bananas. Professor Dale's team is looking to develop gene-edited versions of the QCAV-4 that resist other diseases, such as black sigatoka, and adapt to the changing climate. This approach offers many benefits to global food security and sustainability.

However, the use of genetically modified crops is not without debate in many countries. For India, a country with a strong agricultural sector and a significant stake in banana production, this development carries profound implications.

India is the world's largest producer of bananas, contributing to over 25% of the global production. Bananas not only serve as a staple food for millions across the country but also play a crucial role in the livelihoods of countless farmers. On the one hand, the threat of diseases like TR4 looms large, capable of devastating banana plantations and jeopardising food security. On the other hand, India has taken a nuanced and cautious approach to GM crops particularly those intended for direct human consumption.

When will India get to taste it?

India's regulatory environment for genetically modified crops is stringent, with Bt cotton being the only such crop widely approved for cultivation. The debate around Bt brinjal, the first genetically modified food crop approved by Indian authorities, led to a moratorium on its cultivation amid concerns over biosafety and the lack of long-term impact studies. This precedent highlights the challenges that genetically modified bananas might face in gaining approval and acceptance.

For genetically modified bananas to be considered a viable option in India, they will have to navigate rigorous safety assessments and environmental impact studies. Public perception is equally critical; ensuring transparent communication and demonstrating the benefits of genetically modified bananas in terms of yield, disease resistance, and contribution to food security will be key to gaining societal acceptance.

India also boasts an incredibly rich diversity of banana cultivars, and preserving this genetic heritage will be essential for ecological balance and agricultural resilience. With careful planning, rigorous scientific evaluation, and inclusive dialogue, India can navigate the future of genetically modified crops, ensuring the nation's agricultural prosperity and food security are balanced with safety and biodiversity.

Anirban Mahapatra is a scientist and author. His second popular science book, When The Drugs Don’t Work: The Hidden Pandemic That Could End Medicine, will be published this year. The views expressed are personal.