Citrate synthase in the mitochondrial matrix catalyzes the reaction of oxaloacetate, acetyl-CoA, and H2O to form citrate and CoA-SH. Rice citrate synthase has not been characterized experimentally. Two candidate citrate synthase proteins predicted from analysis of the rice genomic DNA sequence have been identified and distinguished from potential peroxisomal citrate synthase isoforms based on sequence similarity to Arabidospsis thaliana proteins.