CURRENT AND PAST RESEARCH PROJECTS

Deciphering Plant Microbiomes

 
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HOST-MICROBIOME EVOLUTION AND MICROBIAL ADAPTATIONS TO DROUGHT (WAGNER LAB)

Host-associated microbiomes are both vertically transmitted and recruited from the environment, at least partly under the control of the host’s genetics. Therefore, individual microbial lineages have the potential to evolve either (1) independently or (2) closely intertwined with a host organism (i.e. co-evolve). Microbial, specifically bacterial, short generation times (averaging 1-100 hrs) and frequent horizontal gene transfer events make host-microbe evolution even more complex.


We are utilizing a model (maize) and native (Eastern gamagrass) plant system to increase our understanding of how host-microbiome interactions influence microbial adaptation to stress (drought).

Image: Laser ablation topology of root cross section, provided by collaborator Gabriel Castrillo, U. of Nottingham

MAIZE-ASSOCIATED MICROBIAL CULTURE COLLECTION AND MICROBIAL GENOMICS (WAGNER LAB)

We have isolated and identified over 970 bacterial and fungal isolates that can survive in the soil and as maize root endophytes. 

These isolates are being screened for beneficial traits and utilized in a comparative genomics study to link microbial traits to genetic factors.

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MICROBIOTA AND HOST PHENOLOGY (ROPER LAB)

Plant phenology, the timing of annual plant life-cycle events, affects the fitness of the plant and the organisms that are dependent on it. In the context of agriculture, it can affect the potential yield, growing distribution range, and a crops adaptability to climate change. Changes in phenology can be detrimental to pollinator populations, plant yield, pest treatment efficacy, and concerning human health, may lead to premature or prolonged allergy seasons. Recent work has shown that phenology is impacted by environmental factors. However, the impact of biological, particularly microbial, factors on the regulation, timing, and plasticity of plant phenology is still unknown.

I characterized microbiome assembly patterns associated with host phenological stages, indicating that host seasonal development drives microbiome composition.

INTER-MICROBIOME INTERACTIONS (ROPER LAB)

This project focused on observing how symbiotic bacteria influence the colonization of other native bacteria with in the plant. Physical niche partitioning may influence functional roles of the community members.

Preliminary results show that some microbiome members regulate colonization of other microbiome members and that physical niche selections maybe driven more by competition rather than physical and biochemical differences between host compartments.

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THE MICROBIOME AND PLANT DISEASES (ROPER LAB)

The microbiome has the potential to interact with pathogens directly by promoting, impeding, or blocking colonization of the host, or indirectly by provoking a plant response, aiding in host nutrient acquisition, increasing plant growth capabilities, or transforming into secondary or opportunistic pathogens. Microbes may play dual and temporal roles within a pathosystem. These beneficial or injurious interaction with the host and/or pathogen very likely plays essential roles in disease development and plant protection.

I used amplicon-based sequencing to better understand the disease microbial ecology of Huanglongbing (HLB) disease in citrus trees. Additionally, I am providing evidence that a complex of bacteria, fungi, and oomycetes affect HLB development and rate of disease progression.