pH sensing in plants

In plants, the alteration in the pH of extracellular space serves as a cue to regulate a myriad of physiological activities, including ion transport, growth, and defense ( Tsai and Schmidt, 2021 Tsai H.H. Schmidt W. The enigma of environmental pH sensing in plants. Nat. Plants. 2021; 7: 106-115 Crossref PubMed Scopus (26) Google Scholar ). Although it is known that the alkalization or acidification of apoplast is involved in cellular processes such as auxin-mediated cell elongation and pattern-triggered immunity, the molecular mechanism of extracellular pH perception remains unknown. This long-standing question was addressed recently by a research group led by Prof. Hongwei Guo from the Southern University of Science and Technology, China. The team ( Liu et al., 2022 Liu L. Song W. Huang S. Jiang K. Moriwaki Y. Wang Y. Yongfan M. Dan Z. Xing W. Zhifu H. et al. Extracellular pH sensing by plant cell-surface peptide-receptor complexes. Cell. 2022; 385: 3341-3355 Abstract Full Text Full Text PDF Scopus (16) Google Scholar ) used molecular, biochemical, structural, and genetic analyses and revealed the indispensable role of peptide-receptor complexes in pH sensing in Arabidopsis root apical meristem (RAM) (Figure 1).