Advancing from genetic modification to synthetic biology in plant breeding
A farmer whose banana plantation was destroyed by banana bacterial wilt uproots rotten banana from her farm
Photo by Lominda Afedraru
The arguments and controversies arising from use of genetic modification mechanism in plant breeding will continue to surface but agricultural scientists globally are moving on with application of emerging new technologies for improved plant breeding to the benefit of farmers and consumers.
Crop domestication has evolved over the years and it has been a prime example of how humans have modified the many species surrounding them to meet their needs.
Humans have progressed from selecting plants for the most useful flora to actively growing designated crops in the form of agriculture for calculated breeding that is performed today.
As these improvements evolved into modern agriculture, man’s ability to modify the traits of plants for societal needs has become more targeted.
Although many of these traits have revolved around agricultural yield for the purpose of food production, modern society also requires the use of crops as a clean energy source in the form of biofuels.
Scientists globally including those in agricultural sector are engaged in plant breeding using genetic modification methods where a gene from a different plant is identified for disease resistance, drought tolerance and nutrition among others and transferred to the plant of interest.
For farmers to access the end result there has to be a law in place for release of such crop variety known as GMO’s.
However, scientists are now applying new technologies which may not require laws for farmers to access the crops and these include use of application of synthetic biology involving gene editing and use of gene drives.
In contrast to random mutation of the plant in search for natural gene variations in traditional breeding, genome editing is now being applied by agricultural scientists aimed at the targeted modification of plant species in a precise manner.
Dr Teddy Amuge a PHD student of Bioinformatics at the University of Pretoria based at the National Crop Resources Research Institute (NaCRRI) in Namulonge explains that there are two basic steps in plant genome editing.
This includes identifying a gene within a plant which is retarding its growth and is eliminated in order for the plant to continue growing normally.
This can be done by silencing this gene and boosting existing ones whose function is to enable it grow well.
This technology can also apply in eliminating a gene which is making the plant to succumb to diseases or editing a specific gene in the plant to boost its nutrient.
The new field of plant synthetic biology has emerged in recent years and is expected to support rapid, precise and robust improvements in plant breeding process.
“Every single behavior of a plant is controlled by a gene. When a scientist identifies a stunted plant, he or she can silence this gene in the Laboratory to enable the plant grow tall or you simply delete the gene and eliminate it in the life cycle of the plant. There are genes which control disease resistance in the plant. It is the duty of the scientists to ensure this gene is expressed for the plant to resist certain diseases for it to grow normally. We are now moving away from sourcing genes in other organisms to be inserted in plants that are challenged for resistance,” Amuge noted.
To her synthetic biology has been used over the years by scientists in the health sector and those in agricultural sector are trying to catch up.
Explaining the usage of this technology in the health sector, she says scientists usually identify a plant which contains properties of a drug because all plants have a composition of biological chemical.
For instance, Neem tree has anti malaria properties and what pharmacists do is to reproduce chemicals with properties exactly like for Neem tree and develop anti malaria drugs out of it for treatment.
Gene editing is being done by a few scientist in Uganda for research purpose and for the case of Amuge he is carrying out research to understand the gene components that have caused tolerance in cassava against Cassava Brown Streak Virus (CBSV).
“I have studied the plant characteristics to understand the behavior of the gene component. I have discovered those genes that tolerate the virus and in the next stage I can now carry out gene editing to cause resistance to the virus and develop plantlets which are totally free from CBSV,” she explained.
The Executive Manager Biosafety South Africa Dr Jan Hennie Groenewald giving an overview about the new emerging breeding technologies in agricultural science at the International Agri Biotechnology and Bisafety Communication forum in Entebbe noted that it is important to develop agricultural products using technologies such as gene editing because it does not require legal provision for the products to be released to farmers like in the case of GMO’s.
According to Dr Hennie, scientists in the health sector have been developing generic drugs using synthetic biology and these drugs have helped in curing patients suffering from sicknesses caused by different diseases.
“Scientists breeding mosquitos for malaria prevention are already using synthetic biology in the breeding process. This is because there are over 300 species of mosquitoes in the world and those causing malaria are probably two or three. Scientists have silenced the gene that causes reproduction during mating to cause disappearance of female mosquitos in the environment because they are spreading and causing malaria infection in human population. This technology is already working in countries like Brazil to control spread of Zika Virus,” he explained.
To him there is no need to regulate the technology of gene editing because the change in the plant could as well occur naturally although it may take long period of time.
Citing examples of agricultural products developed using gene editing he said scientists in USA have bred mushrooms which remain fresh and do not change colour to brown even if they are kept for a longer period after harvesting and another is herbicide tolerant canola.
To him if the public is opposed to GMO products, then it is better for scientists to bred using emerging new technologies which are easier to apply and cheap.
The minister for Science, Technology and Innovations Dr Elioda Tumwesigye commended agricultural scientists in the country who are applying biotechnology to improve crop varieties for disease and pest resistance as well as for nutritional value.
He urged the public not to misunderstand application of modern biotechnology in plant breeding because it is used world over to breed crops which are high yielding with potential for farmer to earn increased income.
“Scientists exist in this country to help solve societal challenges and as such agricultural scientists must be given the benefit to breed crop varieties in order for families to put food on the table. You know the pest and disease challenges our farmers growing coffee, maize banana are faced with and this can be addressed through breeding biotech crop,”
The minister called upon Ugandan legislators to ensure the Biotechnology and Biosafety Bill is passed into law to enable farmers access crops that have been bred using modern biotechnology.
