The plant microbiome: The dark and dirty secrets of plant growth

Abstract

Terrestrial life depends on a thin layer of top-soil measuring no more than a few cm to around a meter. This nutrient rich zone supports the growth of plants by providing minerals and water they need for growth and photosynthesis. It is in the dark underworld of soil that plant roots interact with perhaps the most complex microcosm of organisms, from bacteria, archaea and fungi to single-celled animals as well as multicellular animals such as nematodes and earth worms. This soil microbiome profoundly alters plant growth and in turn depends on root secretion and is shaped by plant immunity. Summary: This article is about life underground. More specifically it is about the rhizosphere, the zone where plant roots meet the soil. The whole of terrestrial life depends on a few inches of soil. Soil is complicated. The nature of the soil is shaped by the presence of roots. In turn, the microbes in the soil immediately surrounding roots have a profound influence on plant growth and development. The soil microbiome is the community of soil microorganisms. Sampling and analyzing the soil microbiome and the way in which microbes and roots recognize and associate with each other are technically challenging. Here, we discuss new ways to reveal what is happening hidden beneath the soil surface.