Ultra-Weak Photon Emission (UPE): A Biophysical Bridge to Systemic Signalling and Biocommunication

The historical work of Sir Jagadish Chandra Bose challenged human thought on plant life expression. Dr Bose demonstrated a systemic-complex perspective that exhibits rapid, systemic electrical and mechanical responses to stimuli. We hypothesize that Ultra-Weak Photon Emission validates and extends Bose's original vision of highly integrated plant life. This work aims to assess the mechanistic philosophy of reactive machines. Our review of Ultra-Weak Photon Emission (UPE) examines mechanistic perspectives across history and systemic-complex plant biology. We conducted a literature review (2000–2024) to identify experimental studies on Ultra-Weak Photon Emission in plants. A synthesis of contemporary biophysical research and historical narratives explores how biophotons intersect with philosophy and biocommunication. Ultra-weak photon emission in plants connects contemporary biophysics with the philosophical systemic-complex perspective. UPE spatial and temporal expression reflects systemic changes in response to biotic or abiotic stimuli. Further, UPE provides a non-invasive biophysical phenomenon that supports Bose's physiological observations. UPE provides evidence of systemic complexity through theoretical approaches and advanced experimental technologies. Modern studies validate visionary aspects of Bose's research by establishing UPE as a tool that negates biosemiotic discourses. These findings transition the study of whole-plant behaviour from abstract mechanistic models to a quantifiable, systemic-complex (SC) perspective. Together, our work validates Bose's visionary research and establishes UPE as a critical tool for understanding plant perception and signalling.