The banana you eat today Not the same typeAre we eating bananas similar to those eaten by people generations ago? The bananas you had for breakfast today are a variety called Cavendish bananas, but the variety that was in grocery stores until the 1950s was called Gros Michel, which was wiped out by a disease called Fusarium banana wilt (FWB).
Gros Michel’s FWB is Fusarium oxysporum Race 1A fungal pathogen that affects bananas. This fungal infection takes over the plant’s vascular system, inhibiting water and mineral transport and causing the plant to die.
Today, it’s hard to find Gros Michel bananas in American supermarkets. krares/iStock via Getty Images Plus
Plant biologists FusariumDisease-resistant Cavendish varieties have been developed to replace Gros Michel, but the past few decades have seen a resurgence of FWB, caused by a different strain of the same fungus. Tropical Tribe 4, or TR4is once again threatening global banana production.
how Fusarium oxysporum Will it overcome resistance and gain the ability to infect so many different plants?
Two-part genome F. oxysporum
I’m a genomicist I’ve been researching this for the past 10 years. Genetic evolution Fusarium oxysporumAs a species complex, F. oxysporum May cause wilt and root rot Over 120 species of plantsThe specific strain Infect people.
In 2010, My Lab Each one F. oxysporum The genome It is divided into two parts: a core genome that is shared by all strains and encodes essential housekeeping functions, and an accessory genome that varies from strain to strain and encodes specialized functions, such as the ability to infect a particular plant host.
Each plant species has a sophisticated immune response to defend itself against microbial invasion. Therefore, in order to establish an infection, F. oxysporum The fungus utilizes its auxiliary genome to suppress the plant’s own defense system. This compartmentalization allows F. oxysporum Greatly expands host range.
The genome structure of Fusarium oxysporum allows it to have a wide host range, including tomato, cucumber, and watermelon. Edward L. Bernard, Florida Department of Agriculture and Consumer Services, Bugwood.org, CC BY-SA
In a newly published study, my team and colleagues from China and South Africa have found that the TR4 strain that causes Cavendish banana blight Different evolutionary origins When compared to the strain that killed Gros Michel bananas, the sequences of the auxiliary genome were different.
Looking at the interface where the TR4 strain is fighting the Cavendish banana host, some of the auxiliary genes that are activated Releases nitric oxidea gas that is harmful to Cavendish bananas. A sudden burst of this toxic gas neutralizes the plant’s defenses and promotes infection. At the same time, the fungus protects itself by increasing the production of a chemical that detoxifies nitric oxide.
Increasing banana diversity
Tracking the global spread of this new version: Fusarium oxysporumWe believe that the main cause of the recent resurgence of this fungal infection is the spread of A single clone of banana.
Growing a variety of banana varieties can make agriculture more sustainable and reduce disease pressure on a single crop. Farmers and researchers can identify or develop the following banana varieties to suppress Fusarium wilt of bananas: Tolerantor resistance to TR4. Our findings suggest that another approach to protect Cavendish bananas is to design effective nitric oxide scavengers that reduce the toxic pressure of gas explosions.
The banana industry has dark origins.
It may be hard to imagine that consumers who simply love eating bananas could join in the fight against a disease that is devastating the banana crop, but consumers determine the market, and farmers are forced to grow according to market demand.
By intentionally trying more than one variety of banana, you can increase the variety of bananas in your supermarket. There are hundreds of other banana varieties Local fruits and produce are also available for purchase. Help protect plants Diversity Support local producers.
With collaboration between scientists, farmers, industry and consumers around the world, we can avoid future shortages of bananas and other crops.
Li-Jun Ma is a professor of biochemistry and molecular biology at the University of Massachusetts, Amherst. This article is reprinted from conversation Under Creative Commons License.Please read Original article.
