RT Journal Article
SR Electronic
T1 The effects of soil phosphorous content on microbiota are driven by the plant phosphate starvation response
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 608133
DO 10.1101/608133
A1 Omri M. Finkel
A1 Isai Salas-González
A1 Gabriel Castrillo
A1 Stijn Spaepen
A1 Theresa F. Law
A1 Paulo José Pereira Lima Teixeira
A1 Corbin D. Jones
A1 Jeffery L. Dangl
YR 2019
UL http://biorxiv.org/content/early/2019/06/04/608133.abstract
AB Phosphate starvation response (PSR) in non-mycorrhizal plants comprises transcriptional reprogramming resulting in severe physiological changes to the roots and shoots and repression of plant immunity. Thus, plant-colonizing microorganisms – the plant microbiota – are exposed to direct influence by the soil’s phosphorous (P) content itself, as well as to the indirect effects of soil P on the microbial niches shaped by the plant. The individual contribution of these factors to plant microbiota assembly remains unknown. To disentangle these direct and indirect effects, we planted PSR-deficient Arabidopsis mutants in a long-term managed soil P gradient, and compared the composition of their shoot and root microbiota to wild type plants across different P concentrations. PSR-deficiency had a larger effect on the composition of both bacterial and fungal plant-associated microbiota composition than P concentrations in both roots and shoots. The fungal microbiota was more sensitive to P concentrations per se than bacteria, and less depended on the soil community composition.Using a 185-member bacterial synthetic community (SynCom) across a wide P concentration gradient in an agar matrix, we demonstrated a shift in the effect of bacteria on the plant from a neutral or positive interaction to a negative one, as measured by rosette size. This phenotypic shift is accompanied by changes in microbiota composition: the genus Burkholderia is specifically enriched in plant tissue under P starvation. Through a community drop-out experiment, we demonstrate that in the absence of Burkholderia from the SynCom, plant shoots accumulate higher phosphate levels than shoots colonized with the full SynCom, only under P starvation, but not under P-replete conditions. Therefore, P-stressed plants allow colonization by latent opportunistic competitors found within their microbiome, thus exacerbating the plant’s P starvation.