Plant residues are an abundant source of renewable matter, but require targeted dissociation at the tissue scale for the design of high-quality products. This is a huge scientific challenge that crucially depends on the variety of the compositions and histological structures of plant tissues as well as the complex physics of grinding, involving the poorly-understood flow of breakable particles of various shapes and properties. The ambition of this project is to elaborate a generic multiscale approach for realistic modeling of plant comminution accounting for both cellular and granular microstructures of plant residues. This bottom-up approach will proceed from the mechanical and physicochemical interactions at the scale of the relevant constituents (cells, envelopes, organs...) to model intercellular dissociation with the goal of developing single-particle fracture laws that will be validated experimentally and included in dynamic simulations of a large number of particles at the process scale. The methodology that we propose is based on state-of-the art computational (Peridynamics, Discrete Elements) and experimental (histology, multispectral imaging, tomography, milling) approaches. It will be organized in three work packages dealing with 1) Mechanics of fracture at the cell/tissue scales, 2) Fracture behavior at the scale of a single plant residue particle, and 3) Fragmentation process of plant material. The consortium is composed of three partners with complementary expertise, involving early-career and confirmed researchers. The project will benefit from the longstanding experience with tissue characterization methods and grinding of vegetal powders in Montpellier and X-ray and neutron imaging in Grenoble. The originality of PlantCom lies in its multiscale and cross-disciplinary nature, bridging powder process with fracture mechanics and the rheology of granular materials, to elaborate a physics-based toolkit for plant comminution.