What’s past is past, mostly: Brassicaceae host plants mask the feedback
from the previous year’s soil history on bacterial communities, except
when the Brassicaceae hosts experience drought
Abstract
Previous soil history and the current plant hosts are two plant-soil
feedbacks that operate at different time-scales to influence the
structure soil bacterial communities. In this study, we used a MiSeq
metabarcoding strategy to describe the impact of five Brassicaceae host
plant species, and three different soil histories, on the structure of
their bacterial root and rhizosphere communities at full flower. We
found that the Brassicaceae host plants were consistently significant in
structuring the bacterial communities. Four host plants (Sinapis alba,
Brassica napus, B. juncea, B. carinata) formed nearly the same bacterial
communities, regardless of soil history. Camelina sativa host plants
structured phylogenetically distinct bacterial communities compared to
the other hosts, particularly in their roots. Soil history established
the previous year was only a significant factor for bacterial community
structure when the feedback of the Brassicaceae host plants was
weakened, potentially due to limited soil moisture during a dry year.
Understanding how plant-soil feedbacks operate at different time-scales
and are involved in how microbial communities are structured is a
pre-requisite for employing microbiome technologies in improving
agricultural systems.