Introduction
Pesticides are widely used in agriculture to protect crops from pests and diseases, but they have negative impacts on the environment and human health. A possible alternative to pesticides is to enhance the natural defense mechanisms of plants by manipulating their microbiome, the community of microorganisms that live in and around them. In a recent study published in Nature Communications, scientists from the University of Southampton, China and Austria have successfully engineered the microbiome of rice plants for the first time, increasing the abundance of beneficial bacteria that can prevent infections by harmful bacteria.
Methodology
The researchers focused on a specific gene in the rice plant that is involved in the production of lignin, a complex polymer that is found in the cell walls of plants. They discovered that this gene influences the composition of the plant’s microbiome by affecting the levels of certain metabolites, small molecules that are produced by the plant during its metabolic processes. By over-expressing or deactivating this gene, they were able to alter the amount of one particular metabolite, which in turn changed the population of beneficial bacteria in the plant’s microbiome.
Results
The researchers found that by increasing the level of the metabolite, they were able to boost the prevalence of a group of bacteria called Burkholderia gladioli pv. oryzae (BGO), which are known to protect rice plants from bacterial blight, a serious disease that can cause significant yield losses. They also showed that this engineered microbiome was able to suppress the growth of Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial blight, both in vitro and in vivo. Furthermore, they demonstrated that this microbiome engineering approach could be applied to other rice varieties and other crops, such as wheat and maize.
Conclusion
This study is the first to engineer the microbiome of plants in a targeted way, using a single gene as a lever to manipulate the microbial community. The findings could have important implications for sustainable agriculture, as they could reduce the reliance on pesticides and enhance crop resilience to diseases. The researchers also suggest that this framework could be used to explore other opportunities to improve plant health and productivity, such as increasing nutrient provision or drought tolerance, by modifying other genes or metabolites that affect the plant’s microbiome.