The influence of wheat microbiomes on drought stress resilience

Wheat is the most grown crop plant by area worldwide and a widely valued part of western human diet. However,
drought periods, that are projected to increase due to climate change, pose a major agricultural risk to crop
yields. One potential strategy to increase drought stress resilience of wheat is the application of plant-growth
promoting bacteria. In this study, we aimed to identify drought stress suppressing microbiomes through plant
phenotype monitoring. Furthermore, bacteria were isolated from the rhizosphere of drought stressed wheat to
decipher the plant-microbe interactions during drought
We cultivated wheat plants in 20 distinct agricultural soils collected across Lower Austria in greenhouse trails.
To simulate drought stress, a water withholding regime was applied. The five best and worst performing soils
in elevating drought stress resilience were selected based on dry weight, stomatal conductance, as well as water
and chlorophyll content. To control for potential abiotic factors, living microbial cells were extracted using
a 0.2% pyrophosphate solution from each of the selected soils and used as an inoculant for a subsequent experiment.
Inoculated wheat plants were grown in steamed artificial soil under drought stress and controlled
conditions to assess the effect of soil microbiomes and stress on the plant phenotype and wheat-associated microbiomes.
Drought stress had an impact on plant growth, whereas different soil microbiomes had only minor
effects. Treatments with three different soils were selected based on their effect on plant traits. Root and rhizosphere
microbiomes of stressed and unstressed plants were subjected to 16S rRNA gene amplicon sequencing
as well as isolation campaigns. As Flavobacterium strains were prominently isolated, a comparative genomics
analysis has been initiated. We will present results on how drought stress affects wheat growth when grown in
identical soils but containing distinct microbiota.