A plant signalling gene has been identified as a promising target for breeding cereal crops to produce a steeper, narrower root system architecture, but with associated yield penalties in barley.
University of Queensland PhD candidate Richard Dixon said collaborative research with scientists at the Australian National University revealed the gene, known as CEPR1, has a conserved function across multiple grain crops.
“Our goal is to use biotechnology to create a ‘steep, deep and cheap’ plant with a root system that can access water and nutrients in challenging conditions, without significant yield trade-offs,” Mr Dixon said.
“For millennia, plant breeders have been purely focusing on above-ground traits because, until recently, everything underground has been challenging to view.
“We think there is a huge amount of genetic variation that has been lost because we’ve been selecting only for above-ground traits.”
“Previous work by our group using the plant Arabidopsis, a kind of lab rat for plant genetic research, showed CEPR1 controls the shape of the root system and some above-ground traits like seed production,” ANU researcher and co-author Dr Michael Taleski said.
“In this research, we engineered Arabidopsis plants to have versions of CEPR1 found in barley, rice and maize to test if they function similarly.
“It has been proposed that root system shapes could be tailored to different cropping scenarios and environmental conditions to enable more efficient resource capture.
“That would ultimately mean reduced fertiliser costs for farmers, less fertiliser run-off into the environment, and better performance of crops under water limitation.
“Our findings are exciting because they suggest the CEPR1 genetic pathway is a promising target for optimising the root systems of these crops.”
Mr Dixon said that while the initial work with the gene was promising, there are limitations that will have to be addressed through further research.
“In barley, knocking out CEPR1 resulted in yield penalties and steeper, narrower root systems, just like the Arabidopsis mutants.
“We’ve also been growing and harvesting the gene-edited plants in the field to validate the findings in the glasshouse and are in the process of analysing the data.
"We would like to fine-tune the pathway rather than switching off the gene to create root systems that can reach deeper water or nutrients without affecting grain production.
“We’re also looking at whether combining the CEPR1 gene with another target could create deeper root systems.
“And we’re utilising the high-tech root scanning facilities in Germany through UQ’s International Research Training Group (IRTG) to further investigate the plants’ performance under drought and nutrient stress conditions.
“Our results are encouraging because it allows us to think of ways to use this tool to fix problems.”
The research was published in the Journal of Experimental Botany.
It was part of an ARC Linkage project in collaboration with InterGrain.
Images available from Dropbox.
Media: Richard Dixon, r.dixon@uq.edu.au, +61 402 988 109; Dr Michael Taleski, michael.taleski@anu.edu.au; QAAFI Communications, Natalie MacGregor, n.macgregor@uq.edu.au, +61 409 135 651.
The Queensland Alliance for Agriculture and Food Innovation is a research institute at The University of Queensland, established with and supported by the Department of Primary Industries.
