Transcriptional architecture underlying development, adaptation, and domestication in Northern Wild Rice <i>(Zizania palustris</i> L.)

Zizania palustris (Northern Wild Rice) is an aquatic grass native to North America and a crop wild relative of Oryza sativa with ecological, cultural, and agricultural significance. Here, we present a transcriptomic atlas spanning 20 tissues across six major developmental stages. Seed tissues showed shifts in abscisic acid, gibberellin, and ethylene pathways that define the hormonal basis of deep dormancy in this recalcitrant species and its release. Leaf development showed stage-specific reprogramming, from hypoxia-responsive programs in submerged tissues to cell wall remodeling and redox regulation during aquatic-aerial transitions, with photosynthesis and carbohydrate metabolism defining flag leaves and SRG1 divergence emerging as a defining feature of leaf development in Z. palustris . Reproductive tissues expressed duplicated homologs of well-recognized shattering genes with divergent regulation, consistent with subfunctionalization after whole-genome duplication. These findings provide new insight into traits underlying ecological adaptation and domestication in Z. palustris and related grasses.