Press release for new paper Carvalhais et al. (2013) Plant growth in Arabidopsis is assisted by compost-soil derived microbial communities. Frontiers in Plant Science 4:235.
Plant growth has been doubled by adding soil microbes. Plants and soil microbes are constantly interacting in natural and agricultural environments and many examples of one-to-one interactions have been studied. However, the effect of mixed microbial populations on the growth and gene expression of plants still remained largely unknown. This study evaluated the growth of leaves and roots of the model plant Arabidopsis thaliana in the presence or absence (sterile soil) of microbes extracted from compost soil. Surprisingly, leaf growth was doubled in the presence of microbes. Chemical and high throughput gene expression analysis of plant tissues and soil surrounding roots revealed that the added microorganisms facilitated iron acquisition by plants. Microarray analysis indicated that soil microbes also affected other plant processes, including nitrogen acquisition, free radicals production, and defense against diseases. In conclusion, this study showed the main underlying processes occurring in plants during interactions with soil microbial populations and emphasized the important role of soil microbes for plant growth.