Fig. 6

Comparison of the borders among the LSC, SSC, and IR regions of the 37 analyzed plastomes. LSC represents the large single-copy region of the plastome, and SSC represents the small single-copy region of the plastome. IRb and IRa represent the first unit and the last unit of the inverted region, respectively. We highlighted the two IR regions with a pink background color. Different functional groups of genes are drawn in different colors, and their legends are shown in the lower right corner. We use small red arrows to mark the direction of IR region expansion/contraction, and each expansion/contraction is compared from the bottom to the top. A blue five-pointed star on the left side of the Latin name marks the recombination event in the plastome