The seed coat of angiosperms has evolved to provide important adaptive functions, including seed dispersal, embryo dormancy, and germination. The Arabidopsis seed coat has an outer layer of cells that are specialized to produce large amounts of pectic mucilage. On pages 2777–2791 of this issue, Penfield et al. found transposon-induced disruptions of the MYB61 gene in Arabidopsis cause a reduction in mucilage deposition in the developing testa and other phenotypes, and suggest myb61 lines may be defective in some aspects of extracellular secretion. Seed germination and establishment in lines with reduced mucilage production was lower than wild type in conditions of lower water potential, suggesting seed mucilage in germination may increase and buffer the water potential surrounding the germinating seed.