Chromosomal-level reference genome of the ricefield flatsedge Cyperus iria L. that produces insect sesquiterpenoid juvenile hormone

Grass-like plants in the family Cyperaceae, which are commonly known as the sedges, are graminoid and monocotyledonous flowering. They have a wide geographical distribution globally and have been found growing in almost all environments. Cyperus iria L., commonly known as ricefield flatsedge, is a widespread weed in Asia. Previous studies have identified insect juvenile hormone in C. iria, which could cause lethality in mosquito, inhibit crop seed germination, and contribute to antifungal properties. Here, we present a chromosomal-level genome assembly for C. iria. The 489.5 Mb genome assembly is of high physical contiguity, with a scaffold N50 of 2.3 Mbp, and high completeness, with a 97.7% BUSCO score. We include XX transcriptomes from various plant tissues at different conditions, providing a total of 51,340 gene models. We reveal the first complete set of genes involved in sesquiterpenoid production and plant defence for the genus Cyperus, including genes involved in the biosynthesis of sesquiterpenoids via the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways. On the contrary, we could not identify the insect sesquiterpenoid biosynthetic pathway genes, suggesting the detection of its insect juvenile hormone could be due to another endogenous pathway or interactions with symbionts. Our study reveals the first chromosomal-level genome assembly for the weed in the genus Cyperus, and provides a foundation to address a variety of basic and applied questions in the Cyperaceae more widely.