This study investigated the transcriptomic response of the wheat holobiont to decreasing soil water content. Wheat was grown under rainout shelters with varying precipitation levels (100%, 75%, 50%, and 25%). RNA was extracted from roots and rhizosphere and sequenced. Differential abundance analysis comparing 100% and 25% treatments revealed a stronger transcriptomic response in fungal (roots) and bacterial (rhizosphere) partners than in the plant itself. Most differentially abundant transcripts in roots belonged to fungi, while those in the rhizosphere were primarily bacterial. These findings suggest a significant role of the microbiome in the wheat plant's response to drought.

Pranav M. Pande, Hamed Azarbad, Julien Tremblay, Marc St-Arnaud, Etienne Yergeau