Great hopes are placed on a new way to combat plant diseases, using RNA to turn off genes that the pathogen needs to initiate the attack. Now, researchers from SLU and the James Hutton Institute have for the first time investigated how spray-induced gene silencing affects other microorganisms. RNA used to combat Fusarium head blight did not disturb the microbial communities living on the surface of cereal crops, and was thus very specific. This means that the method can be tested in field trials, as a step towards more sustainable agricultural systems.
Fusarium head blight is a major disease affecting cereal crops, including wheat, barley, rye, oats and maize. It is normally caused by the fungus
Fusarium graminearum, which infects the spikes and thereby reduces grain yield and quality. The frequency and severity of this disease has increased in recent years and threatens global food security.
Spray-induced gene silencing is a new technique that could be used to tackle this disease. It involves spraying the crop with a preparation containing double-stranded RNA that is designed to silence specific genes that the pathogen uses to attack the crop. However, before applying this RNA in field trials, it must be ensured that its use does not have unwanted side effects.
A research team from the Swedish University of Agricultural Sciences, together with a colleague from the James Hutton Institute, has addressed this knowledge gap and has now published the first study of how spray-induced gene silencing affects the microbial comunities which live on the surface of cereal crops and should preferably not be disturbed.
“We use a type of double-stranded RNA that regulates or blocks the pathogen's production of certain proteins that it needs to infect the plant,” explains Ramesh Vetukuri, who led the work.
A screening of all microbial genomes on crop surfaces showed that the treatment led to minor changes in the diversity and structure of the bacterial communities, and that fungal communities remained relatively unchanged. The double-stranded RNA thus appears to have reached its targets without disrupting critical microbial communities. This means that spray-induced gene silencing can be used to combat Fusarium head blight without compromising the balance in this ecosystem.
”We are thrilled to be the first to explore how double-stranded RNA-based sprays influence cereal microbiomes. This study bridges a significant gap in research on spray-induced gene silencing and demonstrates its potential to revolutionize crop protection with minimal ecological impact. I think this is the future of sustainable agriculture”, says Ramesh Vetukuri.
”Conventional chemical solutions can harm the environment and public health, making the need for safer alternatives urgent. Our findings are an exciting development for sustainable agriculture”, says Poorva Sundararajan.
”Understanding the broader ecological impacts of innovative plant protection strategies is critical. Our findings reinforce that spray-induced gene silencing can protect crops without disrupting the natural microbial interactions that are essential for plant resilience and growth”, says Mukesh Dubey.
”This is an exciting step towards more sustainable and resilient farming systems. Spray-induced gene silencing provide a much-needed environmentally friendly alternative to chemical fungicides and genetically modified crops”, says Aakash Chawade.
The authors of the study acknowledge support from FORMAS, SLU Centre for Biological Control, The Crafoord Foundation, and the Novo Nordisk Foundation.