Maxing out chemical-free crop protection with dsRNAmax

A software package developed and validated at The University of Queensland can tailor safe, effective and chemical-free crop protection using RNA interference (RNAi).

The dsRNAmax software designs double-stranded RNA (dsRNA) to target pest and pathogen species while excluding off-target species like beneficial insects. The program was developed by PhD candidate Stephen Fletcher and tested by Dr Chris Brosnan and his team in a collaboration with the Department of Primary

Industries (DPI) nematology team.

‘The idea of the software is that it designs a custom dsRNA for a target organism, and we can use it on almost anything across many projects,’ Mr Fletcher said. ‘It will mean that you will not have off-target impacts, and you can add as many off-targets as you like to be excluded.’

Dr Brosnan said dsRNA triggered RNAi is a mechanism that already exists to regulate genes in most species. ‘What we can do is usurp this existing mechanism with dsRNA created by us to target any gene we choose and use it to control pathogens and pests,’ Dr Brosnan said.

‘In our validation study we used three species of nematode provided by the nematology team at the DPI, as well as an off-target nematode species. The software was able to design a single dsRNA which could target all three, irrespective of the number of copies of the gene we were looking at and have no impact on the off-target nematode. We have physically demonstrated that this software can do what we say it does, which is where this paper stands out. As well, our nematode work with DPI is ongoing and very promising.’

Mr Fletcher said the next step for dsRNAmax was to further improve its effectiveness. ‘We will be using machine learning to improve the design to make our dsRNA five to ten per cent more effective, which would make a huge difference in a production system,’ he said. ‘It also means we could use less dsRNA, which will bring down the cost. It was the collaboration with DPI that got us over the line because without the validation system we would not have been able to publish the software.’

The research was published in NAR Genomics and Bioinformatics. Expertise and biological material were provided by the DPI team of Wayne O’Neill, Dylan Corner, Jenny Cobon and Tim Shuey.