Abstract
It is generally said that seeds with pale color coat have weaker dormancy than seeds with dark color coat. This dormancy enhancement was attributed to coat impermeability, physical strength or presence of germination inhibitor.Arabidopsis transparent testa (tt) mutants which have defect in flavonoid metabolism have been reported to have reduced dormancy. We have isolated tt7 allele (TRW71-1) as one of the high temperature resistant germination mutants, and found that tt4-1, tt5-1, tt6-1 and tt7-1 were high temperature resistant but tt3-1 and banyuls were not. Proanthocyanidin content in the seeds showed no correlation with the germination character. In addition, germination of tt4-1, tt5-1, tt6-1 and tt7-1 seeds were inhibited by auxin transport inhibitor, NPA, by a dose dependent manner at high temperature. These results suggest that distribution of auxin in Arabidopsis embryo have a contribution to regulation of germination at high temperature.
