The study investigates the influence of the seed coat on seed dormancy, germination, and longevity in Arabidopsis. The researchers compared mutants with defects in testa pigmentation and/or structure to wild-type seeds. Most mutants showed reduced dormancy, with mutant testas being permeable to tetrazolium salts, indicating altered pigmentation and structural integrity. These changes were associated with reduced seed size and weight, and higher germination rates. Structural and pigmentation mutants deteriorated faster during natural aging, with structural mutants being the most affected. The results suggest that the permeability and thickness of the testa are crucial for controlling seed germination and longevity. The study also highlights the role of phenolic compounds in seed coat function and their potential involvement in limiting water entry and oxygen supply to the embryo.The study investigates the influence of the seed coat on seed dormancy, germination, and longevity in Arabidopsis. The researchers compared mutants with defects in testa pigmentation and/or structure to wild-type seeds. Most mutants showed reduced dormancy, with mutant testas being permeable to tetrazolium salts, indicating altered pigmentation and structural integrity. These changes were associated with reduced seed size and weight, and higher germination rates. Structural and pigmentation mutants deteriorated faster during natural aging, with structural mutants being the most affected. The results suggest that the permeability and thickness of the testa are crucial for controlling seed germination and longevity. The study also highlights the role of phenolic compounds in seed coat function and their potential involvement in limiting water entry and oxygen supply to the embryo.