An international team of researchers, including from the University of Nottingham, UK, uncovered a key gene in plants that helps them use energy more efficiently and capture more water and nutrients in the soil, according to a study published in Proceedings of the National Academy of Science (PNAS).
The regulatory gene — called bHLH121 — regulates the formation of air pockets in the root. These spaces are known as root cortical aerenchyma, and they save the plant energy, which would otherwise be used to feed the root cells in those spaces. This makes roots more efficient as they can use these resources to capture more water and nutrients from the soil. The authors believe this discovery could lead to new the development of new crops that can cope with drought and poor soils and reduce food insecurity around the world. “Identifying this gene and how it works will enable us to create more resilient crops that can withstand water and nutrient stress conditions being experienced as a result of climate change, said Rahul Bhosale, Assistant Professor in Crop Functional Genomics from the School of Biosciences at the University of Nottingham.
In this study, the team used imaging tools to analyse cell division in thousands of root samples. A state-of-the-art new technology called laser ablation tomography, available at the University of Nottingham, was crucial for this work.
“We first performed the field experiments that went into this study starting in 2010, growing more than 500 lines of corn at sites in Pennsylvania, Arizona, Wisconsin, and South Africa. We saw convincing evidence that we had located a gene associated with root cortical aerenchyma,” said Hannah Schneider, Assistant Professor of Crop Physiology at Wageningen University & Research, Netherlands.
The authors showed how the gene works by creating a mutant form lacking the gene bHLH121, which had fewer air pockets. In contrast, overexpression of the gene caused more air space formation. This will eventually be a tool for plant breeders to select varieties that can explore the soil better and grow under suboptimal conditions. “Droughts are the biggest risk to corn growers and are worsening with climate change, and nitrogen is the biggest cost of growing corn, from both a financial and environmental perspective. Breeding corn lines more efficient at scavenging for the nutrient would be a major development,” said Professor Jonathan Lynch, who led the research at Penn State.
Schneider HM, Lor VS, Zhang X, Saengwilai P, Hanlon MT, Klein SP, Davis JL, Borkar AN, Depew CL, Bennett MJ, Kaeppler SM, Brown KM, Bhosale R, Lynch JP. Transcription factor bHLH121 regulates root cortical aerenchyma formation in maize. Proc Natl Acad Sci U S A. 2023 Mar 21;120(12):e2219668120.