The banana has been a common fruit in most parts of the world, but it is currently facing a major threat from Sigatoka complex, which can wipe out the species from the universe in the next five to 10 years, according to University of California plant pathologist Ioannis Stergiopoulos.
There are three fungal diseases that make up the Sigatoka complex. The black one is the biggest threat to the 100 million tonnes that are produced annually in almost 120 countries. Two more diseases include eumusae leaf spot and yellow Sigatoka.
Experts discovered that the fungal diseases shut off the immune systems, while the fungal metabolism adapted itself to match the host plants. Hence, the fungi could produce enzymes breaking down the cell walls of the plant, so that it could feed on carbohydrates and sugar.
Stergiopoulos analysed the fungal attack when he sequenced the genomes of black Sigatoka and eumusae leaf spot, and then compared the results with the earlier sequenced yellow Sigatoka genome.
"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," Stergiopoulos told Digg.
The changes in the host's metabolism as well as the pathogen are probably like a "molecular fingerprint" of the adaptation process, but it has not been studied much. Stergiopoulos feels that this aspect needs to be looked into further.
The banana plant is thought to be widespread in the world, but it is under threat due to fungal disease. It is important that farmers make 50 fungicide applications available annually.
"Thirty to 35 percent of banana production cost is in fungicide applications. Because many farmers can't afford the fungicide, they grow bananas of lesser quality, which bring them less income," Stergiopoulos added.
The research was published in PLOS Genetics.
