Transcriptomic analyses provide new insights into green and purple color pigmentation in Rheum tanguticum medicinal plants.

We found that three chlorophyll degradation enzymes ( and ) were highly expressed in purple samples, which suggests that the purple pigmentation is mainly due to the effects of chlorophyll degradation. Overall, these data may aid in drafting the transcriptional network in the regulation and biosynthesis of medicinally active compounds in the future.