A team of African scientists has made progress in the development of banana and plantain varieties via genetic editing techniques that are resistant to the banana streak virus (BSV), one of the pathologies that hinder the production of these fruits in Africa.
The banana streak virus works by integrating its DNA into the banana genome. When plants are stressed, for example, by drought or heat, viral DNA produces functional viral particles, which eventually cause symptoms of the disease. Therefore, the main epidemics caused by BSV are not due to natural transmission through vector insects, as in the case of HLB citrus disease, or to the use of infected planting materials, but to the activation of the integrated virus in stressful or unfavorable conditions.
The research team, led by Leena Tripathi, senior scientist at the International Institute for Tropical Agriculture (IITA) in Kenya, used the CRISPR / Cas9 system to inactivate the viral DNA of the Gonja Manjaya genome, a banana variety that is commonly cultivated in eastern and central Africa.
The edited plants were generated and tested by Jaindra Tripathi, a banana transformation specialist, and Valentine Ntui, a plant biotechnologist at IITA-Nairobi in collaboration with the University of California at Davis, USA.
The team found that when exposed to drought stress, 75% of the edited plants showed no symptoms of banana streak virus compared to unedited plants, confirming that the viral DNA was inactivated.
"This strategy can be applied to improve breeding lines, which can then be used to develop plantain hybrids that don't allow the virus to activate. The strategy may also allow for global dissemination of the resulting genome-enhanced hybrids," stated Leena Tripathi.
According to the researchers, this strategy could be used to strengthen banana and plantain crops and to develop new hybrids with the improved genome.
“Genetically edited products, unlike genetically modified ones, have their genes simply edited, like deletions, and they don't have any foreign DNA introduced. Genetically edited varieties can be developed and released much faster and are less expensive compared to genetically modified varieties," said Tripathi.