Oral Presentation International Plant Molecular Biology Conference 2024

A journey towards biotech control of plant-invertebrate pests (nematodes, aphids) (#348)

Michael G.K. Jones 1
  1. Murdoch University, Murdoch, WA, Australia

Plant parasitic nematodes are major crop pests: most species are root pathogens, although others attack aerial parts of plants. The biotech journey we followed began in 2006, with the foundation of the company Nemgenix Pty Ltd. This trait development company developed nematode and then aphid resistance traits based on RNAi. It leveraged the genomic data available from C. elegans, since genomic data for plant nematodes was not available at that time. A series of  RNAi-based constructs were developed to control root-knot, cyst and root lesion nematodes, to which were added aphids, as sucking pests with parallels to nematode pests. The main issue for host-induced RNAi resistance was that it had to be transgenic, with issues of costs to develop and acceptance. We also looked at other forms of transgenic resistance. This was followed by investigating spray-induced RNAi as a non-GM alternative, but here the challenges were the cost and stability of dsRNA for field application, uptake, and systemic movement in plants. With the advent of gene-editing, and the prospect that at least SDN-1 forms are being de-regulated and treated as conventionally bred plants, a gene-editing approach to nematode resistance presents a new opportunity for nematode control. However, the strategy required is to edit genes for susceptibility rather than deliver silencing signals, and such genes may have other necessary functions. Nevertheless, the journey will continue, and perhaps gene-editing will finally deliver a cost-effective biotech solution to plant nematode control.