Characterization of the Functional Microbiome of Tobacco

For decades, we have dedicated a great deal of research attention to understanding and optimizing the plant genome via accelerated breeding and in some cases transgenic approaches. While great strides have been made in this area, the movement towards transgenic crops has been slow and cost prohibitive and in many cases public perception not always positive. An alternative approach is to develop a suite of microbial colonizers that can deliver chemical signal(s) in situ to the host plant and modify plant metabolism with no plant transformation. Tobacco has numerous metabolic byproducts that have been keenly sought to be repressed or removed entirely, such as TNSA. Further, improved plant vigor, particularly seedling vigor could save producers considerable time and money prior to transplant if sustainable and cost effective means can be developed. To date, we have strong preliminary data that we can modify metabolism in Tobacco and other plants by alteration of hormonal pathways (Figure 1) or cell wall composition (Xia et al., 2014) via the inoculation with an endophytic bacterial isolate. Our efforts have mainly focused on advancing seedling expansion and development (Figure 1). This approach fits the scope of the Council Mission as we aim to sustainably improve Tobacco productivity and modulate metabolism via non-transgenic approaches. However, in order to maximize the efficiency of the processes we need to know the functional genes. The goal of this proposal is to: 1) Identify the specific genes that can be linked to improved seedling vigor and metabolic optimization. 2) Overlay gene expression changes in the Tobacco plant with the presence of growth promoting microbial effectors to predict specific metabolic changes.