The substitution rates of chloroplast and mitochondria genes sometimes show tremendous variation in parasitic plants, but it is unclear if this is also true for nuclear protein-coding genes. Su and Hu study six protein-coding genes from two Balanophora species in comparison with selected hemiparasitic Santalales species and autotrophic core eudicots. The results suggest five of the nuclear protein-coding genes of the holoparasitic Balanophora are evolving at a much slower rate than 18S nrDNA and mitochondrial matR. Although the mechanism behind this rate heterogeneity is unclear, these sequences are potential candidates for future phylogenetic analysis of Balanophoraceae.
