Use of arduino‐based potentiometric sensors to measure changes in leaf apoplastic pH in common bean ( <i>Phaseolus vulgaris</i> L.)

Abstract Following an abiotic or biotic stress, the pH of the extracellular space or the apoplast of a plant can change dramatically, such as wounding that causes an increase in pH or alkalinization. In this proof‐of‐concept‐study, a newly developed carbon‐based bendable potentiometric sensor was tested for the first time in vivo on common bean ( Phaseolus vulgaris L.). The sensor was able to detect the same magnitude and direction of pH change after wounding as the conventional infiltration‐centrifugation method in five out of eight tested common bean cultivars. This highly scalable, non‐destructive, and cheap carbon‐based sensor could be used in the future within plant breeding to screen large populations of plants for responses to plant stresses.