So much happens on a microscopic level in our crops, and the balance of bacteria in plant roots and soil, as well as contributions from various inputs, is why many farmers are so fascinated with science. And it’s not just an interest in the biology and chemistry, it’s a necessity for their livelihoods, too.
Newly published research in the journal CELL talks about fungi and other filamentous microbes called oomycetes that cause many devastating plant diseases and are together responsible for more than 10 percent of crop loss globally. What’s also interesting is that the study from scientists at the Max Planck Institute for Plant Breeding Research in Cologne, Germany, found that even healthy plants host potentially harmful fungi and oomycetes in plant roots. A plant’s survival in nature is due to the simultaneous presence of a wide range of different co-residing bacteria, which regulate the balance among these different microorganisms in plant roots.
Soil hosts a staggering diversity and number of different microbial organisms such as bacteria, fungi, and oomycetes. These microbes from different kingdoms of life are known to engage in complex interactions with each other and a small subset, collectively called the “root microbiota,” is capable of colonizing the roots of healthy plants. Plants are soil-anchored organisms and their below- and above-ground parts are constantly under attack by various microbial pathogens. An elaborate innate immune system is long known to protect plants against many of these harmful microbes, but it remains unclear whether this machinery alone is sufficient to fully protect plants in nature. Little is known about whether interactions among microbiota members can influence microbial colonization of roots and promote plant health.
The research team addressed these questions by first performing a census of the different microbes associated with the roots and surrounding soil of healthy individuals of the model plant Arabidopsis thaliana from different geographical sites. While root-associated fungal and oomycetal communities exhibited large differences between the different sites, the bacterial communities had a more similar structure, indicating potentially important functions for these root-inhabiting bacteria. Further, the authors found a potential signature of mutual exclusion between bacteria and filamentous microbes in roots, suggesting competition for access to the root niche.