Mapping Reaction-Diffusion Networks at the Plant Wound Site With Pathogens

Area of Science:

• Plant-microbe interactions
• Microbial ecology
• Chemical ecology

Background:

• The rhizosphere, a zone of intense microbial activity around plant roots, plays a vital role in nutrient distribution.
• The precise mechanisms, particularly morphogenic signaling, governing the dynamic mutualistic order within the rhizosphere remain largely unknown.
• Reaction-diffusion chemical networks involving plant and bacterial metabolites can model rhizosphere processes, including spatiotemporal ordering.

Purpose of the Study:

• To investigate the role of reaction-diffusion dynamics in organizing the rhizosphere.
• To map the signaling landscape of the rhizosphere in host and non-host plants, particularly after wounding.
• To utilize *Agrobacterium tumefaciens* and its dual-metabolite receptor system to probe rhizosphere signaling.

Main Methods:

• Constructed reaction-diffusion chemical networks using model plant and bacterial metabolites.
• Employed genetically modified fluorescent strains of *Agrobacterium tumefaciens* with altered receptors for specific plant metabolites.
• Mapped reaction-diffusion dynamics in the rhizosphere of host and non-host plants before and after wounding.

Main Results:

• Reaction-diffusion networks successfully mimicked key rhizosphere processes like oxidative burst kinetics and traveling waves.
• Fluorescent reporter strains provided initial maps of rhizosphere reaction-diffusion dynamics.
• Significant differences in the rhizosphere signaling landscape were observed between host and non-host plants, especially post-wounding.

Conclusions:

• Reaction-diffusion dynamics are fundamental to the spatiotemporal organization of the rhizosphere.
• The study highlights specific signaling networks that likely inform rhizosphere organization and plant-microbe interactions.
• Understanding these dynamic informational networks is crucial for controlling plant pathogens and optimizing rhizosphere function.