Phytohormone dynamics in tomato leaves due to in-situ continuous wearing of sensors.

Tomato has become an increasingly important functional food crop due to its high nutritional value and short growth cycle. However, its production is highly susceptible to compound environmental stresses, leading to substantial yield losses. Currently, in-situ continuous monitoring using wearable sensors offers a novel approach for early warning of stress in tomatoes. Yet, the physical properties of these sensors may trigger leaf stress responses during wear, resulting in distorted hormone monitoring data. To address above problems, this study systematically investigated the effects of key sensor properties including surface hardness, breathability, light transmittance, invasion depth and weight on the dynamic changes of six hormones in tomato leaves: abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene (ET), auxin (IAA), and gibberellin (GA). By designing polydimethylsiloxane (PDMS) sensor simulators with varying parameters and employing enzyme-linked immunosorbent assay (ELISA) for multi-time-point hormone detection, the results demonstrate that sensor physical properties significantly disrupt hormonal balance. Results show that higher hardness induces sharp accumulation of JA and SA, inadequate breathability promotes ethylene and ABA synthesis, and light shading significantly suppresses GA while activating ABA-mediated senescence pathways. This study provides a theoretical and experimental basis for optimizing sensor biocompatibility and improving the accuracy of in-situ monitoring.