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bioRxiv · 10.1101/2025.08.27.672388

A chromosome-scale genome assembly of Hordeumerectifolium: genomic, transcriptomic and anatomicaladaptations to drought in a wild barley relative

Haraldsson, E. B.·Anokye, M.·Rütjes, T.·Toegelova, H.·Tulpova, Z.·Simkova, H.·Feng, J.-W.·Mascher, M.·von Korff, M.
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Abstract

O_LIWild crop relatives are valuable genetic resources for improving stress adaptation in cultivated species, but their effective use depends on high-quality reference genomes integrated with phenotypic and molecular datasets. Hordeum erectifolium, a wild relative of barley (H. vulgare), is adapted to intermittent and prolonged drought and saline soils, making it an excellent model for stress-adaptation research. C_LIO_LIWe assembled a chromosome-scale, annotated reference genome of H. erectifolium comprising 3.85 Gbp, and identified 71,475 genes supported by a tissue-specific gene expression atlas. Comparative morphological, physiological, and transcriptomic analyses under water limitation were conducted with cultivated and wild barley. C_LIO_LIH. erectifolium displayed a greater density of leaf veins and sclerenchyma cells, alongside rapid leaf rolling upon dehydration. Genomic comparisons revealed structural variations, independent transposon-driven evolution, and copy number expansions of desiccation-responsive gene families relative to barley. The transcriptional responses of H. erectifolium and barley to water limitation suggested contrasting drought-adaptation strategies: metabolic down-regulation and survival prioritization in H. erectifolium versus maintenance of metabolic activity and competitiveness in barley. C_LIO_LIOur data suggest that H. erectifolium is genetically primed for survival under drought through anatomical adaptations, gene family expansion, efficient shutdown of growth-related metabolism, and rapid recovery upon rehydration. C_LI

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Haraldsson, E. B., Anokye, M., Rütjes, T., Toegelova, H., Tulpova, Z., Simkova, H., Feng, J.-W., Mascher, M., von Korff, M.. 2025-08-31. A chromosome-scale genome assembly of Hordeumerectifolium: genomic, transcriptomic and anatomicaladaptations to drought in a wild barley relative. https://doi.org/10.1101/2025.08.27.672388

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