Deeper plant roots could boost soil carbon storage

In a new study led by the University of Nottingham, experts are exploring the potential for plants to reach new depths by modifying the angle of their roots. The researchers have discovered a gene in barley and wheat that controls the angle of root growth.

According to the international team of experts, a steeper root angle helps bury carbon deeper in soil. This means the research could ultimately lead to the development of new methods for carbon capture and storage. Furthermore, deeper roots have better access to nutrients, which could make crops more resilient to drought and stress. 

The researchers found that a gene called Enhanced Gravitropism 1 (EGT1) controls root angle by stiffening the core of growing root tips – making it more difficult to bend downwards. The team used X-ray micro CT imaging to show that by disrupting this gene, plants can grow roots with a steeper angle.

“The angle at which barley roots grow down into the soil enables them to capture water and nutrients from different soil layers,” said study co-first author Dr. Haoyu Lou from the University of Adelaide.

“Shallow roots enable plants to capture phosphate and surface water, while deeper, straighter roots can stabilise yield by accessing deeper water and nitrate; they can also bury carbon deeper in the soil.”

“By identifying the genes that control root growth angle we can greatly aid efforts to develop crops that are better adapted to specific soil types and more resilient to fluctuating environmental conditions, helping to mitigate carbon burden and counter the effects of climate change.”

“We have found that mutants lacking function of the EGT1 gene exhibit a steeper growth angle in all classes of roots. Remarkably, the roots behave as if they are overly sensitive to gravity – they are unable to grow outwards from the plant, and instead grow straight down.”

The research was co-led by Rahul Bhosale, an assistant professor in the School of Biosciences and the Future Food Beacon at the University of Nottingham.

“Root angle controls how efficiently plants can capture water and nutrients. For instance, shallow roots best capture phosphate which accumulates in the top-soil region, while steeper roots are better for foraging for water and nitrate in deeper soil layers,” said Bhosale.

“Steeper roots are also important for helping bury carbon deeper into soil. Discovering genes like EGT1 and how they control root angle is critical for developing novel future crop varieties better able to capture nutrients and carbon.” 

The study is published in the scientific journal Proceedings of the National Academy of Sciences.

–—

By Chrissy Sexton, Earth.com Staff Writer