| Summary: | Seeds are specialized plant organs that carry, nurture, and protect plant offspring. Developmental coordination between the three genetically distinct seed tissues (the embryo, endosperm, and seed coat) is crucial for seed viability. In this study, we explore the relationship between the TFs AtHB25 and ICE1. Previous results identified <i>ICE1</i> as a target gene of AtHB25. In seeds, a lack of ICE1 (<i>ice1-2</i>) suppresses the enhanced seed longevity and impermeability of the overexpressing mutant <i>athb25-1D</i>, but surprisingly, seed coat lipid polyester deposition is not affected, as shown by the double-mutant <i>athb25-1D ice1-2</i> seeds. <i>zou-4</i>, another mutant lacking the transcriptional program for proper endosperm maturation and for which the endosperm persists, also presents a high sensitivity to seed aging. Analysis of <i>gso1</i>, <i>gso2</i>, and <i>tws1-4</i> mutants revealed that a loss of embryo cuticle integrity does not underlie the seed-aging sensitivity of <i>ice1-2</i> and <i>zou-4</i>. However, scanning electron microscopy revealed the presence of multiple fractures in the seed coats of the <i>ice1</i> and <i>zou</i> mutants. Thus, this study highlights the importance of both seed coat composition and integrity in ensuring longevity and demonstrates that these parameters depend on multiple factors.
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