The root growth reduction in response to mechanical stress involves ethylene-mediated microtubule reorganization and transmembrane receptor-mediated signal transduction in Arabidopsis

• Published in: Plant cell reports 2021-03, Vol.40 (3), p.575-582
• Main Authors: Okamoto, Takashi, Takatani, Shogo, Motose, Hiroyasu, Iida, Hidetoshi, Takahashi, Taku
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biomedical and Life Sciences; Biotechnology; Calcium ions; Calcium permeability; Cell Biology; Cytoplasm; Dialysis; Elongation; Ethylene; Ethylenes - metabolism; Gene Expression Regulation, Plant; Gravitropism - physiology; Impedance; Kinases; Leucine; Life Sciences; Mechanical impedance; Membrane Proteins - genetics; Membrane Proteins - metabolism; Meristem - growth & development; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - metabolism; Microtubules - metabolism; Molecular modelling; Mutants; Mutation; Original Article; Permeability; Plant Biochemistry; Plant growth; Plant hormones; Plant roots; Plant Roots - growth & development; Plant Roots - metabolism; Plant Sciences; Plants, Genetically Modified; Protein Serine-Threonine Kinases - genetics; Protein Serine-Threonine Kinases - metabolism; Proteins; Receptors; Receptors, Cell Surface - genetics; Receptors, Cell Surface - metabolism; Reduction; Signal Transduction; Stress, Physiological; Vegetal Biology
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-020-02653-6

Key message We found that mutations in a Ca 2+ -permeable mechanosensitive channel MCA1, an ethylene-regulated microtubule-associated protein WDL5, and a versatile co-receptor BAK1 affect root growth response to mechanical stress. Plant root tips exposed to mechanical impedance show a temporal reduction in the elongation growth. The process involves a transient Ca 2+ increase in the cytoplasm followed by ethylene signaling. To dissect the molecular mechanisms underlying this response, we examined the root growth of a series of Arabidopsis mutants with potentially altered response to mechanical stress after transfer from vertical to horizontal plates that were covered by dialysis membrane as an impedance. Among the plant hormone-response mutants tested, the ethylene-insensitive mutant ein3 was confirmed to show no growth reduction after the transfer. The root growth reduction was attenuated in a mutant of MCA1 encoding a Ca 2+ -permeable mechanosensitive channel and that of WDL5 encoding an ethylene-regulated microtubule-associated protein. We also found that the growth reduction was enhanced in a mutant of BAK1 encoding a co-receptor that pairs with numerous leucine-rich repeat receptor kinases to modulate growth and immunity. These results suggest the root growth reduction in response to mechanical stress involves ethylene-mediated microtubule reorganization and also transmembrane receptor-mediated signal transduction.