Updated project metadata. Drought is the prime stressors that land plants have to overcome since their dawn. One strategy that land plants employ is to limit water loss and to transport water via a vascular system, another is to produce desiccation tolerant cells and tissues. In most flowering plants, the latter strategy is limited to seeds and to some extend pollen. Common to desiccation and drought tolerance is the accumulation of small osmolytes and proteins with protective functions. Also common to both strategies is the accumulation of neutral lipids, foremost triacylglycerol (TAG), in cytosolic lipid droplets (LDs) with especially high levels being reached in embryonic tissues. Here, we investigated yellow nutsedge (Cyperus esculentus), a monocot, perennial C4 plant. This species produces stolon-derived underground tubers that can fully desiccate and remain viable for years. Yellow nutsedge stands out, as its tubers store 25-30 % of their dry mass in lipids especially TAG, similar to seeds. We generated nanoLC-MS/MS-based proteomes in five replicates of four stages of tuber development and compared them to the proteomes of roots and leaves, yielding 2257 distinct protein groups. Our data reveal a striking upregulation of hallmark proteins of seeds in the tubers. A deeper comparison to a previously published proteome of Arabidopsis seeds and seedlings indicate that indeed a seed-like proteome was co-opted. This was further supported by an analysis of the proteome of a lipid-droplet enriched fraction of yellow nutsedge, which also displayed seed-like characteristics.