The researchers have not only decoded the genome of the fungus causing black Sigatoka but have also discovered that the fungus has become more unsafe over time by “learning” how to break down the banana plant’s cell walls by producing special enzymes.
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American plant pathologist Ioannis Stergiopoulos was quoted in the journal as saying the Sigatoka complex’s fungal diseases – yellow Sigatoka, eumusae leaf spot and black Sigatoka – could potentially wipe out supply in the next five to 10 years.
The threat to the popular Cavendish banana is most dire.
However, the global banana industry could be wiped out in just five to 10 years by fast-advancing fungal diseases.
It took researchers from University of Calfornia, Davis, and the Netherlands to sequence the genome of three different Sigatoka strains: yellow Sigatoka (Pseudocercospora musae), eumusae leaf spot (Pseudocercospora eumusae), and black Sigatoka (Pseudocercospora figiensis).
The parallel change in the metabolism of the host plant and the pathogen has been largely overlooked and may represent a “molecular fingerprint” of the adaptation process.
Though there are clear implications for smoothie lovers, the effects of a banana shortage would most severely impact countries that rely on bananas as a staple food.
“Because many farmers can’t afford the fungicide, they grow bananas of lesser quality, which bring them less income”.
In addition, Cavendish are vulnerable to the black Sigatoka disease, which attacks the banana plants’ leaves, turns them black and blocks the plants’ photosynthesis.
Understanding the genomic basis of the pathogens’ threat to bananas will hopefully lead to environmentally friendly methods of protection – the enormous amount of fungicide that is now sprayed on these plants poses a threat to plantation workers and nearby communities, and has led to increasingly resistant fungi. To combat the ever-present threat, farmers need to apply fungicide to their crops 50 times a year, which isn’t only costly, but can pose a threat to the environment and human health. “Thirty to 35 per cent of banana production cost is in fungicide applications”, he said.
Which means that one disease could kill all of them.
“The Cavendish banana plants all originated from one plant and so as clones, they all have the same genotype – and that is a recipe for disaster”, Stergiopoulos said, noting that a disease capable of killing one plant could kill them all.
‘It is really a wake-up call to the research community to look at similar mechanisms between pathogens and their plant hosts.
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The team found that the best idea would be to develop a new banana cultivar that we could all eat.
