Chunzhao Zhao, Omar Zayed, Zheping Yu, W. Jiang, Peipei Zhu, Chuan-Chih Hsu, Lingrui Zhang, W. Tao, Rosa Lozano-Durán, J. Zhu
Proceedings of the National Academy of Sciences, 2018
Significance Plants have evolved cell-wall integrity signaling pathways to maintain cell-wall homeostasis in response to stress conditions, but the components involved in the perception and transduction of cell-wall signals are largely unknown. Here we found that the Arabidopsis cell-wall–localized leucine-rich repeat extensins (LRX) 3/4/5 interact with RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23. Mature RALF22/23 peptides interact with the plasma membrane-localized FERONIA (FER) and induce FER internalization. The lrx345 and fer mutants and RALF22/23 overexpressing transgenic plants display similar phenotypes such as retarded growth and increased sensitivity to salt stress. Our work thus reveals that the LRX3/4/5 proteins function with RALF22/23 and FER to define a signaling pathway that is critical for regulating plant growth and salt tolerance. The perception and relay of cell-wall signals are critical for plants to regulate growth and stress responses, but the underlying mechanisms are poorly understood. We found that the cell-wall leucine-rich repeat extensins (LRX) 3/4/5 are critical for plant salt tolerance in Arabidopsis. The LRXs physically associate with the RAPID ALKALINIZATION FACTOR (RALF) peptides RALF22/23, which in turn interact with the plasma membrane-localized receptor-like protein kinase FERONIA (FER). The lrx345 triple mutant as well as fer mutant plants display retarded growth and salt hypersensitivity, which are mimicked by overexpression of RALF22/23. Salt stress promotes S1P protease-dependent release of mature RALF22 peptides. Treatment of roots with mature RALF22/23 peptides or salt stress causes the internalization of FER. Our results suggest that the LRXs, RALFs, and FER function as a module to transduce cell-wall signals to regulate plant growth and salt stress tolerance.
Cited by 32 publications.
Field of study: Chemistry