The genome of the glasshouse plant noble rhubarb (Rheum nobile) provides a window into alpine adaptation

Abstract

Glasshouse plants are species that trap warmth via specialized morphology and physiology, mimicking a human glasshouse. In the Himalayan alpine region, the highly specialized glasshouse morphology has independently evolved in distinct lineages to adapt to intensive UV radiation and low temperature. Here we demonstrate that the glasshouse structure - specialized cauline leaves - is highly effective in absorbing UV light but transmitting visible and infrared light, creating an optimal microclimate for the development of reproductive organs. We reveal that this glasshouse syndrome has evolved at least three times independently in the rhubarb genus Rheum. We report the genome sequence of the flagship glasshouse plant Rheum nobile and identify key genetic network modules in association with the morphological transition to specialized glasshouse leaves, including active secondary cell wall biogenesis, upregulated cuticular cutin biosynthesis, and suppression of photosynthesis and terpenoid biosynthesis. The distinct cell wall organization and cuticle development might be important for the specialized optical property of glasshouse leaves. We also find that the expansion of LTRs has likely played an important role in noble rhubarb adaptation to high elevation environments. Our study will enable additional comparative analyses to identify the genetic basis underlying the convergent occurrence of glasshouse syndrome.

A high-quality genome assembly and phylogenetic analysis for the glasshouse plant, Rheum nobile, shed light on its evolutionary history and ability to adapt to intensive UV radiation in a low-temperature, alpine environment.

Publisher

Nature Portfolio

Publication Date

7-10-2023

Publication Title

Communications Biology

Department

Biology

Document Type

Article

DOI

https://dx.doi.org/10.1038/s42003-023-05044-1

Keywords

Transposable elements, Molecular evolution, Translucent bracts, Divergence times, Annotation, Tool, Alignment, Polygonaceae, Prediction, Retrotransposons

Language

English

Format

text

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