Plant cell walls are composed of various polymers mainly comprising polysaccharides, phenolic compounds and proteins, which typically define the physical and structural properties of plant cells. Recent data have shown how cell wall composition is also pivotal for stress sensing and tolerance mechanisms, which confers additional plasticity to plants, allowing them to respond to various environmental stimuli. In this Special Issue of Plant and Cell Physiology – organized by Taku Demura, Misato Ohtani, Toshihisa Kotake and Jenny Mortimer – we explore the latest pioneering developments in plant cell wall research, through a series of invited reviews and research articles (introduced on pp.1787-1790). These reports highlight the areas in which research in this field is expanding to also include interdisciplinary approaches geared at understanding plant biomechanics, while other research efforts are invested in engineering cell wall properties to develop plants as sustainable carbon-neutral biomass resources.