Endotherapy or Trunk Injection: Decoding Plant Signals for Sustainable Delivery in Perennial Species

Perennial plants form complex systems in which chemical, acoustic, and microbial communication sustains the physiological integrity of the plant holobiont. Advances in the understanding of this “language,” expressed through the phyllosphere, rhizosphere, and endosphere, have revealed how stress, defense, and cooperative signals shape both the plant microbiome and its hydraulic architecture. Within this context, vegetative endotherapy emerges as a technique capable of interacting with these internal processes, provided it is applied under appropriate physiological conditions and with formulations compatible with the vascular environment. Unlike foliar spraying and soil applications such as drenching, which may affect large volumes of soil and water and disrupt edaphic microbiota as well as surface and groundwater, endotherapy delivers compounds directly to the endosphere. Consequently, this approach can reduce product losses and environmental impacts while supporting sustainable strategies aligned with the Sustainable Development Goals and Nature-based Solutions. This short review discusses stress responses within plant compartments and the associated microbiome, examining how these dynamics relate to vegetative endotherapy in perennial plants and highlighting how precision agriculture can enhance the efficiency and sustainability of this technique.