The immune system of animals is extremely complex and helps defend against a plethora of diseases. Plants, on the other hand, are not as lucky when it comes to defense. Plants have a few systems to stop chemicals and diseases from moving in, but overall are very susceptible to infection. Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have found that many plants are relying on microbes in the soil to defend themselves against diseases and pathogens.
Past studies had shown that one or two microbes were used to protect against pathogens and some fungal infections in plants, but the scientists at Berkeley Lab found that there are actually many more microbes that form a complex network to protect sugar beets (the plant model used). There were many microbes in the soil of the sugar beets, so the scientists used a chip (PhyloChip) that could detect the presence of tens of thousands of microbes in the soil without the need to culture them. Soil samples from the beets were modified to show six different levels of disease suppression and were analyzed with the PhyloChip. Though there were thousands of bacteria present, 17 species were in great abundance. Some bacteria in this group of 17 had not been found to have a disease suppressing ability, but were shown to work synergistically with other bacteria that did such as the known fungal fighter Psuedomonas.
This study showed that plant immunity is far more complex than it was previously thought to be; instead of one or two microbes protecting plants a community of microbes work together in a relationship that is beneficial to all parties involved. While the microbes help protect the plants, the plants in turn supply energy to the microbes in the form of carbon. This information can be used in the future to understand plant immunity better which can hopefully help improve crop quality and output