Pranav Pande

INRS-Institut Armand Frappier
Metatranscriptomic responses of the wheat holobiont to drought intensity

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

Wheat production in western Canada is affected by increasing and recurring drought, with anticipated decreases of 20% in 2017 as compared to 2016. Conventional approaches of wheat breeding can partly solve this problem, but the time taken to generate new and successful varieties cannot match the rate of declining wheat yields. Alternatively, manipulating the plant associated microbiota could result in rapid improvement in wheat resistance to water stress. However, the combined transcriptomic responses of the wheat and its microbiota (the wheat holobiont) under water stress are unrecognized. The principal aim of this experiment was to determine the metatranscriptomic response of the wheat holobiont to water stress in the field. Wheat was grown in the field and received 100%, 75%, 50% or 25% of the natural precipitation using rain exclusion shelters. RNA was extracted from the rhizosphere soil and roots samples collected in July, at the peak of the growing season. Root eukaryotic and rhizosphere prokaryotic mRNA libraries were constructed independently and sequenced using Illumina HiSeq. The preliminary results show that both abundances and activities of the prokaryotic, as well as eukaryotic communities, are affected by the levels of precipitation in the wheat rhizosphere soil. Further analysis of the metatranscriptomic data will provide an in-depth characterization of the transcriptomic response and the specialized pathways involved in drought tolerance of the wheat holobiont. Our longer-term objective is to engineer the wheat holobiont for the production of drought resistant and resilient wheat plants.