BOOK OF ABSTRACTS 79 IHSS&IWA26 / BRNO / CZECHIA / 23–28 August 2026 Tuesday, 25 August 2026 / Hall B+C Research Frontiers slabs placed in cover glass chambers with 3D printed root combs to direct root growth. The plants were grown in long-day conditions (16h day/8h night) at 22°C, 60% humidity, 120µmol photons for 7 days. Complementary to the [Ca2+]cyt signaling, the anionic oxonol dye DiBAC4(3) served as a slow response translational probe for measuring shifts in plasma membrane potential. Simultaneously, ROS production was visualized using the reagent 2‘-7‘-dichlorofluorescin diacetate (DCFH-DA). The 7-day old seedlings were imaged using a Nikon Eclipse TE2000-U fluorescence microscope. Following 3 minutes of baseline signal imaging, the quinones and flavonoids were introduced singly or as mixtures, and the images were captured once every second for 20 min in total. Normalized signal intensity, expressed as ∆F/ F0, a relative measurement of fluorescence signal change, was calculated. It is the difference between a time-dependent fluorescence signal (F) and baseline fluorescence (F0), divided by the baseline. Characterizing these transient signaling events provides a molecular bridge between the immediate perception of functional groups and the subsequent stimulation of plant growth. This mechanistic understanding will potentially assist in designing novel humic products tailored for predictable field performance and optimized plant development and provide the basis for a method to predict humic-based biostimulant potential. References 1. Lamar, R.T. (2020). Possible Role for Electron Shuttling Capacity in Elicitation of PB Activity of Humic Substances on Plant Growth Enhancement. In The Chemical Biology of Plant Biostimulants (eds D. Geelen and L. Xu). 2. Santos, M.P., Zupunski, M., Monda, H. et al. (2025). Humic acids modify root architecture in Arabidopsis through H+-ATPase-dependent target of rapamycin activation in concert with Ca2+ and ROS signaling. Chem. Biol. Technol. Agric. 12, 47. Acknowledgement The work is supported by Huma Inc.
RkJQdWJsaXNoZXIy NDA4Mjc=