A new discovery has helped scientists in finding a signal which causes roots to stop growing in hard soils and can be switched off to allow them to grow through compacted soil. This could be an important breakthrough that helps plants to grow in the most damaged soils.
A team led by scientists from the University of Nottingham’s Future Food Beacon and Shanghai Jiao Tong University have found how the plant signal ‘ethylene’ causes roots to stop growing in hard soils. But when this signal is disabled, roots can push through the soil.
Hard (compacted) soils represent a major challenge facing modern agriculture that can reduce crop yields over 50% by reducing root growth, causing significant losses annually. Europe alone has over 33-million-hectares of soil which is prone to compaction, and this is the highest in the world as the numbers say. This compaction of soil reduces root penetration and uptake of water and nutrients. The mechanism under root compaction hasn’t been clear until now.
“Understanding how roots penetrate hard soils has huge implications for agriculture, as this knowledge will be crucial for breeding crops more resilient to soil compaction. Our team’s identification that the plant signal ethylene controls root responses to hard soil open up new opportunities to select novel compaction resistant crops” said Professor Malcolm Bennett from the University of the Nottingham School of Biosciences.
Researchers used the X-ray Computed Tomography scanners available at the Hounsfield Facility at the University of Nottingham to visualise in situ how plant roots responded to compacted soil.
Professor Sacha Mooney from the University of Nottingham and Director of the Hounsfield Facility explained that initially, they were on an assumption that hardness of soil was preventing the roots from penetrating. But after using the imaging approach, they could see that roots continued to grow even in very hard soils when the ethylene signal was cut off. This allows for growing new crops, which can go deeper into soils and thus get the missing amount of nutrients and water.
Bipin K. Pandey, Guoqiang Huang, Rahul Bhosale, Sjon Hartman, Craig J. Sturrock, Lottie Jose, Olivier C. Martin, Michal Karady, Laurentius A. C. J. Voesenek, Karin Ljung, Jonathan P. Lynch, Kathleen M. Brown, William R. Whalley, Sacha J. Mooney, Dabing Zhang, Malcolm J. Bennett. Plant roots sense soil compaction through restricted ethylene diffusion. Science, 2021; 371 (6526): 276 DOI: 10.1126/science.abf3013
Press Release: University of Nottingham