[Wolfgang Schmidt] Plant pH sensors-a sine qua non of phenotypic plasticity
POST:
Receiving information on external pH is critical to steer adaptive responses to a plethora of signals associated with the proton concentration in the rhizosphere. Surprisingly, plant pH sensing did not appear to be a popular concept during the past decades and a ‘pH detector’ as a stand-alone system with the sole duty of monitoring the external proton concentration was considered inessential. Recently, however, it was shown that such a system is in fact employed by Arabidopsis roots, a system that monitors external pH and, subsequently, calibrates the intricate tradeoff between growth and defense (Liu et al. 2022, Cell). While this finding provides solid evidence for the ability of plants to perceive information on external pH, it also raises the question as to whether there is more to discover. In a recent Opinion paper, Isabel Vélez-Bermúdez and Wolfgang Schmidt speculate that the puzzle of environmental signals in general and the sensing of proton concentrations in the apoplast in particular is far from being complete (doi: 10.3389/fpls.2023.1227279). The paper is the first submission of a Research Topic on this subject, edited by Isabel Vélez-Bermúdez (IPMB), Christoph Martin Geilfus (Humboldt University, Berlin), and Li Liu (Max-Planck Institute for Breeding Research, Cologne), the leading author of the study that identified the first pH sensor in plants. The article collection is hosted by Frontiers in Plant Science (sections Plant Cell Biology, Plant Abiotic Stress, and Plant Nutrition).