Soil compaction represents a major challenge for modern agriculture. Compaction is intuitively thought to reduce root growth by limiting the ability of roots to penetrate harder soils. We report that root growth in compacted soil is instead actively suppressed by the volatile hormone ethylene. We found that mutant Arabidopsis and rice roots that were insensitive to ethylene penetrated compacted soil more effectively than did wild-type roots. Our results indicate that soil compaction lowers gas diffusion through a reduction in air-filled pores, thereby causing ethylene to accumulate in root tissues and trigger hormone responses that restrict growth. We propose that ethylene acts as an early warning signal for roots to avoid compacted soils, which would be relevant to research into the breeding of crops resilient to soil compaction.

Department of Forest Genetics and Plant Physiology Umeå Plant Science Centre Swedish University of Agricultural Sciences Umeå Sweden

Department of Plant Science Pennsylvania State University University Park PA 16802 USA

Joint International Research Laboratory of Metabolic and Developmental Sciences School of Life Sciences and Biotechnology Shanghai Jiao Tong University Shanghai 200240 China

Laboratory of Growth Regulators Institute of Experimental Botany of the Czech Academy of Sciences and Faculty of Science of Palacký University CZ 78371 Olomouc Czech Republic

Plant Ecophysiology Institute of Environmental Biology Utrecht University 3584 CH Utrecht Netherlands

Rothamsted Research West Common Harpenden AL5 2JQ UK

School of Agriculture Food and Wine Waite Research Institute University of Adelaide Waite Campus Glen Osmond South Australia 5064 Australia

School of Biosciences University of Birmingham Birmingham B15 2TT UK

School of Biosciences University of Nottingham Sutton Bonington LE12 5RD UK

Universities of Paris Saclay Paris and Evry CNRS INRAE Institute of Plant Sciences Paris Saclay Bât 630 91192 Gif sur Yvette France

Fac Rev. 2022 Jul 25;11:20. doi: 10.12703/r-01-0000014. PubMed

References provided by Crossref.org

Cytokinins regulate spatially specific ethylene production to control root growth in Arabidopsis

Ethylene inhibits rice root elongation in compacted soil via ABA- and auxin-mediated mechanisms