Plants use 'mechanical strategies' to push through soil - study
A new study led by experts at the University of Nottingham uncovers how plants fight their way through hard soil to thrive.
The research, carried out in collaboration with researchers at Shanghai Jiao Tong University and the University of Copenhagen, has discovered that plants use a sophisticated mechanical strategy - one that mirrors engineering and construction design - to force their roots through compacted soil.
The hardening of soil caused by heavy machinery, livestock, or erosion is common in modern agriculture.
When soil becomes densely packed, plant roots struggle to grow downward.
As a result, crops develop shallow root systems that cannot reach the deep reserves of water and nutrients they need to survive drought or climate stress.
Plant hormone
Led by Dr. Bipin Pandey, associate professor in the School of Biosciences at the University of Nottingham, the team revealed that a plant hormone called ethylene acts as the master regulator of this process.
Dr Panday said: “When soil becomes compacted, ethylene builds up around the root.
"The root senses this signal and begins to completely remodel its architecture."
The researchers found that ethylene switches on a gene called OsARF1, which in turn reduces cellulose production in the specific middle layer of root cells.
This makes those cells thinner, softer, and more flexible, allowing them to swell and expand when the root encounters resistance.
At the same time, the root reinforces its outermost cell layer, making it thicker and stronger.
“In other words, the root behaves like a perfectly designed mechanical object: the wider the structure and the stronger its outer shell, the better it can resist buckling under pressure,” Dr. Pandey explained.
The combination of a soft, expandable core and a rigid outer casing transforms the root into a living biological wedge, enabling it to pry apart dense soil as it grows.
Mechanical strategies
Prof. Staffan Persson, senior author from the University of Copenhagen said: “It’s astonishing to see plants use mechanical strategies that mirror principles used in civil engineering.
"Nature has solved the challenge of soil resistance in an elegant and highly optimised way.”
Beyond its scientific significance, the work has implications for global agriculture.
Dr. Pandey explained: "Understanding this mechanism gives us a powerful blueprint for creating crops with deeper, stronger roots.
"If we can breed or engineer plants that use this strategy more effectively, we can develop crops that thrive in compacted soils, use water more efficiently, and withstand climate extremes."
According to the researchers, as soil compaction intensifies worldwide due to modern farming practices and climate-driven drought, this discovery potentially opens pathways to building more climate-resilient crops.
