A team of UQ scientists has developed a breakthrough that has the potential to solve one of the major threats to global food security. BioClay is an agricultural nanotechnology innovation that could help reduce food production losses to pests and pathogens, without the toxic environmental impacts of current chemical sprays.
Crop viruses are part of the pest and pathogen burden that reduces global food production by a massive 20 to 40 per cent, even as an estimated 795 million people – one in nine – do not have enough food to lead a healthy life.
It’s a statistic that has troubled Queensland Alliance for Agriculture and Food Innovation agricultural biotechnologist Professor Neena Mitter for years.
“Coming from India, agriculture is in my DNA,” Professor Mitter said.
Professor Mitter said, until now, the platforms available to protect crops were either through using insecticides and pesticides, or through genetic modification. But both these methods have certain hurdles.
“With insecticides, the issues involve toxicity and resistance,” she said.
“Existing insecticides are broad-spectrum insecticides that can damage not only the pests we are targeting, but can also impact other flora and non-pest insects.
“With genetic modification, there are issues surrounding acceptance and regulation.”
BioClay uses a plant defence mechanism known as RNA (ribonucleic acid) interference, or gene silencing, which has been used to develop genetically modified, transgenic, disease-resistant crops. But in this case, Professor Mitter’s team is delivering gene silencing as a non-genetically modified, non-toxic spray by partnering it with clay nanoparticles, co-developed by former UQ Professor Max Lu and Professor Zhi Ping (Gordon) Xu at UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN).
“The key element here is that double-stranded RNA (dsRNA) is the trigger molecule for gene silencing – we just take that sequence from the pathogen, load that sequence on the clay molecule, and then we have this wonderful spray that we can use to protect crops,” Professor Mitter said.
“The possibilities for BioClay are endless. But our first point of call is protection against viruses, especially in vegetable crops.
“The only way farmers can protect their fields from viruses is either by uprooting the plant, or by using pesticides.
“BioClay actually uses the sequence from the virus itself. We load it onto the clay nanoparticles and we spray it. It acts like a vaccination for plants, whereby the dsRNA is slowly released onto the surface of the leaf, it enters into the plant, and the plant is primed for defence. So once we have sprayed, the clay particle acts as a controlled-release mechanism.
“This clay is absolutely degradable. The clay left on the surface simply degrades in the presence of natural carbon dioxide and moisture.”
Professor Mitter paid tribute to Professor Lu, UQ’s former Provost and current University of Surrey Vice-Chancellor, for his support in the early stages of the development of BioClay, and for initiating the partnership with other UQ scientists at the AIBN.
“I was giving a lecture on gene silencing in 2011 and Professor Lu happened to be listening to that seminar,” Professor Mitter said.
“We later had a meeting and I highlighted that I wished we could deliver the gene silencing method as a spray. That’s where the genesis of the idea was born, and he suggested I meet with his AIBN colleague Professor Xu.”