Targeting Microbes in Bulk

There are more microbes on Earth than stars in our galaxy, but only a tiny fraction have been discovered. An approach called metagenomics — a type of DNA sequencing — may help scientists learn more about these elusive organisms, according to a paper by College of Agricultural Sciences researchers.

With leaves holding up to 100 million bacterial cells per gram and the space around a plant's roots containing up to one trillion bacteria, microbes have ample opportunity either to help or harm a plant's health. However, the vast majority of these microbes cannot be examined via traditional methods.

Verónica Román-Reyna, assistant professor of global change pathology, said metagenomics can help by enabling researchers to analyze multiple microorganisms from one bulk sample simultaneously, offering a view of the entire microbial community in an environment without the need to culture each organism individually.

The researchers said the approach could help scientists better understand the reasons behind plant disease outbreaks — such as the emergence of new species or reemergence of known microbes — as well as make it possible to investigate plant diseases without prior knowledge of the pathogens, overcoming the limitations associated with unculturable organisms.

—Katie Bohn