Wind, rain, herbivores, obstacles, neighbouring plants, etc. provide important mechanical cues to steer plant growth and survival. Mechanostimulation to stimulate yield and stress resistance of crops is of significant research interest, yet a molecular understanding of transcriptional responses to touch is largely absent in cereals. To address this, we performed whole-genome transcriptomics following mechano-stimulation of wheat, barley and the recently genome-sequenced oat. The largest transcriptome changes occurred ±25 min after touching, with the majority of genes being upregulated. While most genes returned to basal expression level by 1-2h in oat, many genes retained high expression even 4 h post-treatment in barley and wheat. Functional categories like transcription factors, kinases, phytohormones and Ca2+ -regulation were affected. Also cell wall-related genes involved in (hemi)cellulose, lignin, suberin and callose biosynthesis were touch-responsive, providing molecular insight into mechanically-induced changes in cell wall composition. Furthermore, several cereal-specific transcriptomic footprints were identified that were not observed in Arabidopsis. In oat and barley, we found evidence for systemic spreading of touch-induced signalling. Finally, we provide evidence that both jasmonic acid (JA)-dependent and JA-independent pathways underlie touch-signalling in cereals, providing a detailed framework and marker genes for further study of (a)biotic stress responses in cereals.
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