The present invention relates to nucleotide sequences commonly designated CJAS1 comprising a novel gene from plants. The novel gene encodes a protein that is involved in seed formation and is associated with plant defense. The invention further relates to the use of the nucleotide sequence in the sense or antisense orientation to inhibit the expression of the plant gene corresponding to the CJAS1 sequence as a means to alter seed metabolism in plants, particularly cruciferous plants, more particularly Brassica species, to generate seeds with reduced fiber content and/or altered seed coats. The invention also relates to similar genes expressed in other plant species. The invention also relates to the discovery that the CJAS1 gene is involved in proanthocyanidin (PA) formation.