Plants are our major source of renewable biomass. Since cell walls represent some 50% of this biomass, they are major targets for biotechnology. Major drivers are their potential as a renewable source of energy as transport fuels (biofuels), functional foods to improve human health and as a source of raw materials to generate building blocks for industrial processes (biobased industries). To achieve sustainable development, we must optimise plant production and utilisation and this will require a complete understanding of wall structure and function at the molecular/biochemical level. This overview summarises the current state of knowledge in relation to the synthesis and assembly of the wall polysaccharides (i.e. the genes and gene families encoding the polysaccharide synthases and glycosyltransferases (GlyTs)), the predominant macromolecular components. We also touch on an exciting emerging role of the cell wall–plasma membrane–cytoskeleton continuum as a signal perception and transduction pathway allowing plant growth regulation in response to endogenous and exogenous cues.