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bioRxiv · 10.1101/2020.08.07.240580

Regulatory signatures of drought response in stress resilient Sorghum bicolor

Parvathaneni, R. K.·Kumar, I.·Braud, M.·Eveland, A. L.
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Abstract

The effects of drought stress can be devastating to crop production worldwide. A grand challenge facing agriculture is development of crop varieties with improved drought resilience through breeding or biotechnology. To accelerate this, a mechanistic understanding is needed of the regulatory networks underlying drought response in crop genomes and the genetic elements that modulate them. Here, we explore the regulatory landscape of sorghum [Sorghum bicolor (L.) Moench] in response to controlled-environment drought stress. Sorghum is a C4 cereal crop with innate drought resilience. To define molecular signatures of drought response, we mapped genome-wide chromatin accessibility using an Assay for Transposase Accessible Chromatin by sequencing and analyzed parallel transcriptional profiles in drought-stressed sorghum shoot and root tissues. Drought-responsive changes in accessibility were largely in proximal promoters of differentially expressed genes and also in distal regions. Data were integrated to infer gene network connections and cis-regulatory modules underlying drought response and the transcription factors that control them. Inspection of pan-genomic data and phenotyping across sorghum diversity revealed variation in genomic signatures that associated with water use efficiency. Our analyses provide drought-inducible regulatory modules in sorghum that can be leveraged for fine-tuning responses to stress, mining for advantageous alleles, and translating across species.

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Parvathaneni, R. K., Kumar, I., Braud, M., Eveland, A. L.. 2020-08-10. Regulatory signatures of drought response in stress resilient Sorghum bicolor. https://doi.org/10.1101/2020.08.07.240580

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