Abstract:
Plants walk a fine line between friend and foe in the microbial world. This thesis uncovers how a desert-adapted bacterium protects plants from pathogens, and how an immune hub enables plants to engage with beneficial microbes.
First, I investigated Pseudomonas argentinensis SA190, a root-associated ally that shields Arabidopsis and tomato from Pseudomonas syringae through direct inhibition and host-assisted inhibition. Its biocontrol effect remains strong even in complex microbiomes when aided by specific microbial partners.
Separately, I identified BIK1 as a key immune regulator that helps plants balance growth and defense in response to beneficial bacteria. Without BIK1, immune overactivation disrupts microbial diversity and blocks growth promotion.
Together, these discoveries reveal how plants manage microbial threats and alliances—offering new insights into building resilience through natural microbial interactions.

Bio:
Baoda Han is a Ph.D. candidate in Plant Science working under the supervision of Professor Heribert Hirt. Her research explores plant-microbe interactions, with a focus on microbial biocontrol and immune regulation in plants. Her doctoral work investigates the beneficial effects of Pseudomonas argentinensis SA190 in protecting plants from bacterial pathogens, and identifies BIK1 as a key signaling hub integrating cues from beneficial microbes to support plant health. Before joining KAUST, Baoda earned her Master’s degree in Cell Biology from Northeast Forestry University, China, and her Bachelor’s degree in Biology from Inner Mongolia University. She has also worked as a research assistant at KAUST and as a research technician at the National Institute of Biological Sciences (NIBS) in Beijing, contributing to projects on plant immunity and cancer transcriptomics. Baoda brings over a decade of experience in plant molecular biology, immune signaling, and host-microbe interactions.