Two-Axis Metabolomic Architecture of the Cistanche deserticola Succulent Stem

Cistanche deserticola is a holoparasitic medicinal plant that has lost photosynthesis and lives entirely underground; its reduced genome and subterranean lifestyle predict weak spatial metabolic organization. We tested this using untargeted metabolomics of 132 samples from 22 plants, each stem divided along two axes: tissue type (epidermis vs. internal tissues) and longitudinal position (upper, middle, lower).