TRANSLOCATION OF ADENINE-NUCLEOTIDES IN THE MITOCHONDRIA OF MALE-STERILE AND MALE FERTILE SORGHUM

The translocation of ATP from the inside to the outside of the mitocho ndrial membrane has been studied in a male sterile (2219 A) and a male fertile (2219 B) Line of sorghum. The translocation of ATP was found to be substantially lower in case of mitochondria from the male steril e line. The affinity of adenine nucleotides to the translocator protei ns of the mitochondrial membrane was found to be almost one half in ca se of 2219 A as compared to 2219 B when the K-m for ATP-ADP was determ ined by two different assays. It is proposed that the inadequate suppl y of ATP in the cytosol resulting from its inefficient translocation m ay contribute to the male sterility in this line.