Plastome-wide rearrangements and gene losses in carnivorous droseraceae

Abstract

The plastid genomes of four related carnivorous plants (Drosera regia, Drosera erythrorhiza, Aldrovanda vesiculosa, and Dionaea muscipula) were sequenced to examine changes potentially induced by the transition to carnivory. The plastid genomes of the Droseraceae show multiple rearrangements, gene losses, and large expansions or contractions of the inverted repeat. All the ndh genes are lost or nonfunctional, as well as in some of the species, clpP1, ycf1, ycf2 and some tRNA genes. Uniquely, among land plants, the trnK gene has no intron. Carnivory in the Droseraceae coincides with changes in plastid gene content similar to those induced by parasitism and mycoheterotrophy, suggesting parallel changes in chloroplast function due to the similar switch from autotrophy to (mixo-) heterotrophy. A molecular phylogeny of the taxa based on all shared plastid genes indicates that the “snap-traps” of Aldrovanda and Dionaea have a common origin.