PlantRing: A high-throughput wearable sensor system for decoding plant growth, water relations, and innovating irrigation.

The integration of flexible electronics with plant science has generated various plant-wearable sensors, yet challenges persist in their application to real-world agriculture, particularly in high-throughput settings. Overcoming the trade-off between sensing sensitivity and range, adapting sensors to a wide range of crop types, and bridging the gap between sensor measurements and biological understandings remain primary obstacles. Here, we introduce PlantRing, an innovative, nano-flexible sensing system designed to address these challenges. PlantRing employs bio-sourced carbonized silk georgette as the strain-sensing material, offering an exceptional detection limit (0.03%-0.17% strain, depending on sensor model), high stretchability (tensile strain up to 100%), and remarkable durability (season-long use). PlantRing effectively monitors plant growth and water status by measuring organ circumference dynamics, performing reliably under harsh conditions, and adapting to a wide range of plant species. Applying PlantRing to study fruit cracking in tomato and watermelon has revealed a novel hydraulic mechanism characterized by genotype-specific excess sap flow within the plant to fruiting branches. Its high-throughput application has enabled large-scale quantification of stomatal sensitivity to soil drought-a long-standing aspiration in plant biology-facilitating the selection of drought-tolerant germplasm. Combining PlantRing with a soybean mutant has led to the discovery of a potential novel function of the circadian clock gene GmLNK2 in stomatal regulation. More practically, integrating PlantRing into feedback irrigation achieves simultaneous water conservation and quality improvement, signifying a paradigm shift from reliance on experience or environmental cues to plant-based feedback control. Collectively, PlantRing represents a groundbreaking tool poised to revolutionize botanical studies, agriculture, and forestry.