The Biomedical Science Journal for Teens has put research into banana Black Sigatoka disease in the spotlight. The disease is threatening commercial Cavendish banana crops worldwide, as the fungus that causes it has developed resistance to the chemicals that are supposed to control them. Researchers also detected a specific protein in the fungus, that triggers the resistance mechanism of the plant. These yet unknown disease resistance genes could be used to save the banana industry.
In order to further support the sustainable production of bananas researchers wanted to find out more about the genetic basis of disease resistance to Pseudocercospora fijiensis strains, which cause the Black Sigatoka or “black leaf streak disease” (BLSD). Researchers isolated the DNA of the fungus, sequenced its whole genome and built a genetic map to complete the genome picture to better understand the relationship between the banana and its pathogen.
Also, they found a gene that is coding a protein, a so-called effector protein, which triggers a resistance mechanism in wild bananas. Upon recognition, the plant kills the infected cells and surrounding cells, thereby stopping the spread of the infection. Bananas recognizing this protein most likely possess a resistance gene. This could greatly help banana breeding and production.
Less bananas due to reduced photosynthesis
When bananas are affected by BLSD, the fungus destroys the leaf tissue which reduces photosynthesis and thus, crop yields. Farmers can control BLSD only through fungicides, and this greatly increases the economic and environmental costs to produce bananas. Moreover, the frequent use of fungicides leads to strains that are increasingly resistant to these chemicals.
Further reading
Read the whole article in Science Journal for Kids
http://www.sciencejournalforkids.org/uploads/5/4/2/8/54289603/fungus_genome_article.pdf
The article is based on the PLOS genetics article: ‘Combating a Global Threat to a Clonal Crop: Banana Black Sigatoka Pathogen Pseudocercospora fijiensis (Synonym Mycosphaerella fijiensis) Genomes Reveal Clues for Disease Control’ http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005876