Lisica, L. | bioRxiv Science

bioRxiv2026

CO2-concentrating nanoparticles drive progressive photosynthetic and cell-wall remodelling in Arabidopsis thaliana cells

Plant cells offer a distinctive platform for biohybrid engineering because they combine growth and proliferation with photosynthetic carbon acquisition and the continuous fabrication of structurally complex biomass. Harnessing these capabilities could enable living systems in which synthetic functionality develops together with cellular physiology and material organization. Yet nanomaterial engineering of proliferating plant cell populations remains largely unexplored. Here, we establish a biohybrid system combining photosynthetically active Arabidopsis thaliana suspension cells with chitosan-modified polyethyleneimine (gPEI-Chi) nanoparticles, a synthetic CO2-concentrating nanomaterial. By supplying fresh nanoparticles at each subculture, newly generated cell populations were successively functionalized, driving progressive changes in cellular and multicellular phenotypes. Nanoparticle functionalization reduced net headspace CO2 accumulation, increased chlorophyll content and induced stage-dependent reorganization of photosynthetic function and carbon-handling pathways. These physiological changes were accompanied by altered cell wall regeneration and progressive remodelling of cell wall composition, spatial organization and ultrastructure, ultimately promoting more cohesive multicellular aggregates. Our findings establish successive nanomaterial functionalization as a strategy to steer the evolving physiology and structural organization of proliferating plant cell populations, opening opportunities for plant biohybrid systems and engineered living materials.

plant biology↗

bioRxiv2024

Rhamnogalacturonan-II dimerization deficiency impairs the coordination between growth and adhesion maintenance in plants

Cell adhesion is a fundamental feature of multicellular organisms. In plants, cell adhesion is mediated by the cell wall, but the control and maintenance of cell adhesion during growth and development remains poorly understood1. Here we uncover the role of a component of the cell wall, rhamnogalacturonan-II (RG-II) and its capacity to crosslink in the presence of Boron2, as a key regulator of plant cell adhesion maintenance. We show that RG-II dimerization deficiency leads to cell adhesion defects. Importantly, the analysis of mur1 mutants with RG-II dimerization defects uncovers a cell adhesion pathway that is distinct from that identified by the analysis of pectin deficient mutants3. We found that mutations in two cell wall integrity sensors, RESISTANCE TO FUSARIUM OXYSPORUM 1 and RECEPTOR-LIKE PROTEIN 44, as well as supplementation with the hormone brassinosteroid can partially rescue the adhesion defects associated with RG-II dimerization deficiency. We also show that adhesion defects associated with RG-II dimerization deficiency are related to increased epidermal tension as well as decreased homogalacturonan levels in the cell wall, which can also be rescued by supplementation with brassinosteroid. Overall, we propose that RG-II dimerization defects alter cell adhesion directly (reduced crosslinks) but also indirectly through cell wall integrity sensing, brassinosteroid signalling, cell wall remodelling and cell layer growth coordination. Thus, our results uncover the involvement of cell wall integrity sensors and hormonal signalling in the coordination between growth and adhesion maintenance in plants, which is a key feature for complex multicellularity. Highlights- RG-II dimerization is required for cell-cell adhesion in plants. - Cell wall integrity sensors and brassinosteroid signalling mediate cell adhesion downstream of RG-II dimerization. - Cell detachments due to defective RG-II dimerization are caused by weakened middle lamella and higher tissue tension.

plant biology↗