Rate heterogeneity of holoparasitic Balanophora

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.