Microbiome research may be a hot topic today, but people have been manipulating microbiomes since at least the ancient Romans. Farmers have long noticed that different soils have properties such as suppression disease in crops or boosting nitrogen fixation, and we now know that these effects are often due to the soil microbiome. Jo Handelsman (one of the fearless leaders of this meeting) describes how community dynamics can explain the effectiveness of many attempts at microbiome manipulations.
One of Jo’s early studies of the microbiome was using Bacillus cereus to reduce disease in alfalfa. Without next-generation sequencing, this was quite a task! Her research led to the “camoflage hypothesis,” where plant pathogens in the soil detect plants by their associated microbes. Treating seeds with Bacillus changes their microbiomes to look more like soil than roots, camoflaging the plants from their pathogens. The genetics of the plant also plays a role – some plants that have been bred for disease resistance may function by modifying their microbiome.
Despite the vast history of microbiome manipulations, there are still many mysteries surrounding microbial communities, and new methods can help us answer these questions. Hopefully we’ll hear more about those new methods in the next two days!