A team of scientists have found a signal which causes roots to stop growing in compacted, hard and low-quality soil, and also a way this signal can be switched off.
The team at the University of Nottingham found that the reason plants grow better in high-quality topsoil and do not grow at all in harder soils is because of the plant hormone ethylene, which is given off by plant roots senses how compact the soil around it is.
Instead of the roots trying to punch through and failing, which might constrict the roots and cause problems for the plants, the plant simply stops growing the root if it senses more compact layers.
If a plant was developed to have less sensitivity to an ethylene signal, it would in effect turn off this defence mechanism and enable roots to simply punch through the hard soil.
This discovery has the potential to change the face of agriculture, as more crops can be grown on less-than-ideal soil, a major benefit for an industry where 50 per cent of crop yields are reduced as a result of shorter roots.
The tests the team made were made on rice crops initially, before moving onto Arabidopsis, finding that despite 100 million years of evolutionary difference, both plants used the same soil sensing signal.
There are other tests the team need to make before this discovery can go further, such as testing whether this ethylene signalling system works on different kinds of soils other than loamy sand and clay textured soils.