Life without bananas, can we even imagine it? It might actually happen, according to new research based on three fungal species responsible for the disease named Sigatoka affecting bananas. In that case, we would have from 5 to 10 years to enjoy some of the most delicious banana crops, and it would be the end of them. The paper is published in PLOS Genetics.
Looking into the genome of three fungi strains known to be threatening to banana crops left researchers from the University of California with a shocking conclusion as the evolutionary path of the fungi tells a tale of its own: they have been transformed to such an extent that they could become gruesome banana killers!
That was the bad news. The good news is that scientists can attempt to save our bananas! The very instrument that led to the dreadful evaluation can be used to tackle the problem: knowledge of the genetic sequence of the terrible, terrible fungi, can not only be used to conclude of the most abominable of things, but also to find ways to prevent bananas from being wiped out.
Sigatoka has already impacted harshly on banana crops: yields have decreased by 40% annually because of it. The researchers of the new paper have found that two of the fungi strains [yellow Sigatoka (Pseudocercospora musae), eumusae leaf spot (Pseudocercospora eumusae), and black Sigatoka (Pseudocercospora figiensis)] have grown to be more dangerous: if they could once dismantle the crop’s immune system, they can now mess with its metabolism.
“We have demonstrated that two of the three most serious banana fungal diseases have become more virulent by increasing their ability to manipulate the banana’s metabolic pathways and make use of its nutrients,” says one of the study authors, Ioannis Stergiopoulos.
Why are bananas so vulnerable to tiny fungi that their very existence is being threatened? According to the explanation of Stergiopoulos, this has much to do with their nature: most commercial bananas grow from shoot cuttings, and not from seeds; these are normally called Cavendish bananas which are all clones of each other (that is, they have the same genetic make-up), as they come from one plant. Having the same genotype can be disastrous as a disease affecting one plant will also influence all of the others; so, if one goes extinct, all the others will too.
How to save our beloved Cavendish bananas, then? Researchers have suggested to modify the crops, making them resistant to all three strains of Sigatoka fungi by using the latter’s genomic data. Another solution would be to concoct fungicides that would interfere with the fungi’s influence on bananas.
Our bananas are in danger. The fruit is so common that its extinction is, perhaps, inconceivable. This research proves that the threat is indeed real. As scientists attempt to save the crops, enjoy bananas as much as you can while knowing that they might soon disappear!