Food security is being threatened by diseases and pests and the use of chemical pesticides have proven to be detrimental to human health. As a result, scientists went into genetic modification of crops to make them disease-resistant.
This solution raised more questions as genetically-modified foods are believed in some quarters, to be unsafe for humans, hence the rush for organic foods. To resolve the issue of chemical pesticides and its consequences on health, researchers at the University of Surrey and University of Queensland, Australia, using nanotechnology, have developed a new degradable, non-toxic spray to help tackle pests and diseases, two major threats to food security.
By Ebele Orakpo with Agency report
PLANTS vaccination: Armed with the belief that plants have their own immune systems which can be stimulated to fight diseases just like in humans and other animals where attenuated disease agents are injected into the body and it responds by producing antibodies to fight the disease.
In a publication in the journal, Nature Plants, research leader, Professor Neena Mitter of University of Queensland noted that when plants are exposed to double-stranded Ribonucleic Acid (RNA) from the pathogen, it elicits a response that enables the plant to fight the attacker. “The naked RNA works very well, but it only lasts two to three days,” said Mitter; so there is a need for reapplication every few days and that would be very expensive. This led her to look for a better solution.
BioClay: What Mitter, an Agricultural biotechnologist did was to combine BioClay with the RNA from common plant viruses and apply it to leaves of the plants needing protection. This protected the plants for 30 days because it sticks to the leaves, even in heavy rain. BioClay eventually breaks down, leaving no harmful residue.
“Once BioClay is applied, the plant ‘thinks’ it is being attacked by a disease or pest insect and responds by protecting itself from the targeted pest or disease,” she said. “If you use a chemical, pathogens are clever and can adapt, but with BioClay, we use RNA from the pathogen to kill the pathogen itself,” said Mitter
Application: “Combining the BioClay with the RNA is a fairly simple process… the clay has a positive charge and the RNA is negatively charged so they stick together.”
Mode of operation: The researchers said BioClay works by disabling specific genes in plants and protecting plants from disease-causing pathogens without altering their DNA. The RNA switches off gene expression, preventing plants from being susceptible to a virus.
Speaking on the breakthrough, President/Vice-Chancellor of the University of Surrey and co-author of the research paper, Professor G.Q. Max Lu, said: “This is one of the best examples of nanoparticles being effective for biological molecular delivery with a controlled release rate for combating diseases in plants or animals.
“The discovery will produce huge benefits for agriculture in the next several decades, and the applications will expand into a much wider field of primary agricultural production.” “BioClay is a beautiful combination of biology and nanotechnology,” Mitter said, hoping to have a commercial product on the shelves in three to five years.
The clay helps the molecules stick to the plant, and then peels off over time. “We are using that RNA to silence a gene in the pathogen and that RNA has nothing to do with the plant, and has no similarity to the crop,” she said.
“We are not modifying the genome of the plant, we are not doing genetic modification; we are just spraying it with RNA.”