Angiosperm reproductive structures (anthers and ovules/seeds) are complex assemblies containing highly specialized, metabolically diverse, and in some cases genetically distinct compartments. Their successful development depends both on strict inter-tissue coordination, and upon selectively gated inter-tissue communication, particularly at the metabolic level. For these two requirements to be met, dynamic, extensive, and precise remodelling of tissue interfaces, affecting both symplastic (direct cytoplasm-cytoplasm) and apoplastic (involving diffusion through the extracellular matrix) connectivity, is a prerequisite. In the first part of my talk I will concentrate on apoplastic modifications occurring between key compartments in the developing seeds and anthers of Arabidopsis thaliana. I will use both published and unpublished work to illustrate how peptide-mediated inter-tissue dialogues are used in both systems to ensure the timely deposition of intact apoplastic filters (barriers). In the second part of my presentation I will present recent unpublished work on the functional and compositional characterisation of a novel apoplastic filter (barrier) present within the maternal tissues of the developing anther.