Did you already know that the bananas you eat today usually are not the identical variety because the ones people ate just a few generations ago? The banana you’ll have eaten for breakfast today is a spread called the Cavendish banana, while the banana that was available in grocery stores until the Nineteen Fifties was a spread called the Gros Michel, which was worn out by a disease called Fusarium wilt of banana, or FWB.
FWB of Gros Michel was attributable to Fusarium oxysporum Race 1a fungal pathogen that affects bananas. This fungal infection kills a plant by attacking its vascular system and blocking water and mineral transport.
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Plant biologists developed the Fusarium-resistant Cavendish variety as a alternative for Gros Michel. However, in recent many years there was a resurgence of FWB, attributable to one other strain of the identical fungus called Tropical Race 4 or TR4once more threatens global banana production.
How is Fusarium oxysporum gain the power to beat resistance and infect so many various plants?
The two-part genome of F. oxysporum
I’m a genomicist who has spent the last decade developing the genetic evolution of Fusarium oxysporumAs a species complex F. oxysporum could cause wilting and root rot in over 120 plant speciesCertain strains also can Infect people.
In 2010 my laboratory discovered that everybody F. oxysporum Genome can divided into two parts: a core genome common to all strains that encodes essential housekeeping functions, and an adjunct genome that varies from strain to strain and encodes specific functions, equivalent to the power to contaminate a specific plant host.
Every plant species has a classy immune response to defend itself against microbial invasions. To establish an infection, each F. oxysporum strain uses its accessory genome to suppress a plant’s unique defense system. This functional compartmentalization enables F. oxysporum to significantly expand its host range.
Edward L. Barnard, Florida Department of Agriculture and Consumer Services, Bugwood.org, CC BY-SA
In our newly published study, my team and colleagues in China and South Africa found that the TR4 strain that kills Cavendish bananas has a different evolutionary origin and different sequences in its accessory genome in comparison with the strain that destroyed Gros-Michel bananas.
When we investigated the interface between the TR4 strain and its Cavendish banana host, we found that a few of its activated accessory genes Release nitric oxidea gas that’s harmful to the Cavendish banana. This sudden burst of toxic gases facilitates infection by disabling the plant's defense system. At the identical time, the fungus protects itself by increasing the production of chemicals that detoxify nitric oxide.
More banana variety
In tracking the worldwide spread of this new edition of Fusarium oxysporumWe realized that certainly one of the essential causes of the recent resurgence of this fungal infection is the dominance of a single banana clone within the international banana industry.
Growing different banana varieties could make agriculture more sustainable and reduce disease pressure on a single crop. Farmers and researchers can control Fusarium wilt in bananas by identifying or developing banana varieties that are tolerant or resistant to TR4. Our results suggest that one other solution to protect Cavendish bananas is perhaps to develop effective nitric oxide scavengers to cut back the toxic pressure of the gas eruption.
It is difficult to assume that a consumer who simply enjoys eating bananas can take part in the fight against the disease that’s destroying the banana crop. But consumers dictate the market and farmers are forced to grow what the market demands.
You may also help increase the variability of bananas in your supermarket by specifically choosing a number of of the opposite Hundreds of other existing banana varieties after they appear there. You also can buy local varieties of other fruits and agricultural products to help preserve plant diversity and support local producers.
Global collaboration between scientists, farmers, industry and consumers may also help avoid future shortages of bananas and other crops.
image credit : theconversation.com