SARDI’s Dr Kelly Hill hopes to turn molecular biosensors into practical on-farm tools.
Biosensors based on the pheromones that grain insects use to detect each other could potentially be a basis for new pest-detection tools for stored grain.
Using pheromone detection to identify insect pests, and molecules for spore detection that can alert a grower much earlier to the presence of a pathogen in a crop, are some of the areas of research being investigated by South Australian Research and Development Institute (SARDI) researcher and 2013 GRDC Innovation Investment Grant recipient Dr Kelly Hill.
The pheromone research was undertaken by Dr Hill as part of a Cooperative Research Centre (CRC) for National Plant Biosecurity project exploring technologies to facilitate earlier detection of pests in stored grain.
She explains that insects use pheromones to communicate; research has found that stored grain insect species use several of these pheromones. In her initial project Dr Hill investigated the pheromone receptors that red flour beetles (Tribolium castaneum) use to detect each other. The research found three receptor candidates and some potential target volatiles (chemicals) produced by the beetles.
“By developing a technology based on insect-derived olfactory receptors we aimed to find detectors that would be suitable for use as sensors in a highly sensitive biosensor device,” Dr Hill says.
“We envisaged a device that is like a detector dog that can perform real-time detection and identification of a wide range of volatile chemicals but in a cheap, robust and constantly available machine form.”
The rationale was that earlier and more precise detection would help lower pest-control costs and contribute to the wider ongoing efforts to alleviate pest and disease resistance to chemicals.
The pheromone project was not continued but Dr Hill is still investigating the potential of biosensors as practical farm-management tools. “There are many practical challenges to overcome in the pathway to such tools, but if successful, the outcomes could be very useful,” she says.
Dr Hill says biosensors have the potential to aid better management practices for pests and pathogens and could help improve the accuracy of treatment decisions, particularly timing and residue thresholds.
She says further investigation is required to test the on-farm potential of these technologies.
Dr Hill’s interest in biosensors was sparked during her undergraduate degree in nanotechnology. “The biological side of nanotechnology has many applications in areas such as drug delivery, tissue engineering, new biological probes and biosensors,” she says.
Her PhD, based in human health, investigated new technologies and tests to monitor a group of cell surface receptors important in many physiological processes including sight, taste and smell.
“My experience in working with these particular biological molecules and their integration into array and biosensor platforms led to the CRC for National Plant Biosecurity project at SARDI Entomology with Dr Richard Glatz,” she says.
It was during this project that she became aware of other areas in the grains industry in which faster, more specific and field-adaptable diagnostics were needed.
“I was interested in adapting some of the new diagnostic techniques and molecules that are more commonly explored for their applications in medicine into agricultural applications, such as in-field diagnostic tools for plant fungal pathogens. That interested the GRDC, which funded some research within the innovation investment program,” Dr Hill says.
Dr Hill and Dr Glatz’s team was one of five groups to receive funding in 2013.
“Current methods used to screen against plant pathogenic fungi, for example, require expertise and time. The primary aim of the GRDC-funded research was to investigate new diagnostics for quick, accurate and affordable methods or tools to detect fungal pathogens in stored grain and crops,” Dr Hill says.
“To do this it was necessary to determine whether the differences in the coatings of fungal spores were great enough to produce molecules specific to the spore – molecules which could then be used as detectors in biosensors.
“Application-wise, the GRDC aim is to provide an in-field test, or kit, that contains the specific detectors for known pathogens against which the infected material can be screened,” Dr Hill says.
Dr Hill says that it can be frustrating and worrying sending off samples and waiting for answers. This diagnostic delay could also potentially be costly in terms of crop damage or loss: “That’s why we are investigating technologies that would add to the toolkit for quicker, accurate decisions on disease causes and controls.”
Dr Kelly Hill,
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