The present invention relates to the isolation, purification, characterization and use of a mitochondrial pyruvate
dehydrogenase kinase (PDHK)
gene [SEQ ID NO:1](pYA5; ATCC No 209562) from the
Brassicaceae (specifically
Arabidopsis thaliana). The invention includes isolated and purified
DNA of the stated sequence and relates to methods of regulating
fatty acid synthesis, seed
oil content, seed size / weight,
flowering time, vegetative growth,
respiration rate and
generation time using the
gene and to tissues and plants transformed with the
gene. The invention also relates to transgenic plants,
plant tissues and
plant seeds having a
genome containing an introduced
DNA sequence of SEQ ID NO:1; or a part of SEQ ID NO:1 characterized in that said sequence has been introduced into an antisense or
sense orientation, and a method of producing such plants and
plant seeds. The invention also relates to substantially homologous
DNA sequences from plants encoding proteins with deduced
amino acid sequences of 25% or greater identity, and 50% or greater similarity, isolated and / or characterized by known methods using the sequence information of SEQ ID NO:1, and to parts of reduced length that are still able to function as inhibitors of
gene expression by use in an anti-sense, co-suppression or other
gene silencing technologies.