The microbiome living in or on an organism is critical to that organism's health. It influences everything from growth and development to behavior to disease susceptibility. How an organism gets the best possible microbiome during its development is key to its lifetime health and reproductive success. However, we know very little about how the processes by which microbiomes are transmitted among individuals affects organism health. This knowledge gap becomes especially important when building predictions about how interfering in the transfer of microbes between individuals might matter. For example, there has been discussion of how caesarean section birth might reduce the transmission of microbiota from mother to offspring, and in agriculture there are numerous common practices, such as sterilization of seeds or crop rotation, that likely impact the movement of plant-associated microbes across generations. This research project will focus on the consequences of differences in how tomatoes, a model agricultural crop, get their microbiomes. It will compare how vertical transmission, from parent to offspring, or horizontal transmission, among unrelated organisms, affects microbiome establishment, adaptation, and function. The outcomes of this work will be relevant to the development of agricultural practices that better incorporate the potentially useful role of the plant microbiome for crop yield. Undergraduate students from underrepresented groups will also be involved in the project, and researchers will also work with local teachers to create teaching materials based on the research.
The proposed work uses a model tomato plant - phyllosphere (leaf associated) microbiome system to determine both the short term (ecological) and longer-term (evolutionary) consequences of interrupted microbiome transmission between generations on host-microbiome interactions. By manipulating the likelihood that seedlings will be colonized by microbiota coming from parental plants versus unrelated plants, the work will directly test the impact of transmission mode on microbiome successional dynamics, adaptation, and function. The combination of microbial experimental evolution, culture-independent sequencing, and metagenomic analyses will allow for a causal link to be established between microbiome transmission mode and the taxonomic and functional diversity of phyllosphere microbiota. The empirical work will be complemented by theory on how vertical microbiome transmission affects host-microbiome coevolution. Together, the work will determine the importance of vertical transmission in shaping host-microbiome interactions.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
