Plants in natural and agricultural environments are continuously exposed to a plethora of diverse microorganisms resulting in microbial colonization of roots and the rhizosphere. This process is believed to be accompanied by an intricate network of ongoing simultaneous interactions. In this study, we examined Arabidopsis thaliana roots and shoots in the presence or absence of whole microbial communities extracted from compost soil. The results show a clear growth promoting effect on Arabidopsis shoots in the presence of soil microbes compared to plants grown in microbe-free soil under otherwise identical conditions. Element analyses showed that iron uptake was facilitated by these mixed microbial communities which also led to transcriptional downregulation of genes required for iron transport. In addition, soil microbial communities suppressed the expression of marker genes involved in nitrogen uptake, oxidative stress/redox signaling, and salicylic acid (SA)-mediated plant defense while upregulating jasmonate (JA) signaling, cell wall organization/biosynthesis and photosynthesis. Multi-species analyses such as simultaneous transcriptional profiling of plants and their interacting microorganisms (metatranscriptomics) coupled to metagenomics may further increase our understanding of the intricate networks underlying plant-microbe interactions.
Keywords: Arabidopsis, gene expression, iron deficiency, plant growth promotion, plant-microbe interactions, soil microbial communities
Citation: Carvalhais LC, Muzzi F, Tan C-H, Hsien-Choo J and Schenk PM (2013) Plant growth in Arabidopsis is assisted by compost soil-derived microbial communities. Front. Plant Sci. 4:235. doi: 10.3389/fpls.2013.00235
Received: 13 March 2013; Accepted: 14 June 2013;
Published online: 04 July 2013.
Edited by:Marcel Dicke, Wageningen University, Netherlands
Reviewed by:Maria J. Pozo, Consejo Superior de Investigaciones Científicas, Spain;
Copyright © 2013 Carvalhais, Muzzi, Tan, Hsien-Choo and Schenk. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Peer M. Schenk, Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sciences, The University of Queensland, John Hines Building 62, Mansfield Place, Brisbane, QLD 4072, Australia e-mail: email@example.com