b'Jeffrey Dangl, the John N. Couch distinguished professor of biology and an investigator of the Howard Hughes Medical Institute at the University of North Carolina at Chapel Hill, in his lab with lab manager Theresa Law.one another. But were beginning to understand that you mightCurrent Realitybe able to substitute one microbe for another to fulfill a neces- The challenges of invasion and persistence doesnt mean bio-sary chemical pathway, she says, which would therefore makelogicals on the market today arent effective. the invader bacteria more attractive to the existing community. Sure, some of them are clearly snake oil. But many of them Another avenue of research is syn-comms: synthetic bacte- do work under particular settings or under particular conditions, rial communities. Where one bacteria might not be able to breakLeach says. into an existing community, a whole purpose-built communityIn some cases, a short-term biological gain is itself sufficient might have a stronger chance at invasion and persistence. benefit. For example, coating a seed with the soil bacteria that One of the things that people are exploring is, can we makeare associated with the primary plant growth regulators auxin, a synthetic community? Can we put the microbes together, if weethylene and cytokinin could get that seed off to a stronger start, understand what it takes for them to survive and colonize in thatpotentially helping the resulting plant survive its most vulnerable community, in that environment? Leach says.germination and emergence stage. Even if a syn-comm cant ever be engineered to adequatelyIn other cases, a microbes benefit is that it stimulates a plants establish itself in a real-world setting, the fundamental knowl- defense response to repel pathogenic microbes. Or, treating with edge gained from this research will lay the groundwork for majora biological can initiate a different kind of critical plant response. future steps forward.In my rhizobia example, instead of having to recruit those There are a lot of complexities were grappling with aboutrhizobia naturally in the soil and then have them proliferate to how you develop communities, how you manipulate them andform a module, youre flooding the seed and, once it emerges, how you make them work in a real setting, but its exciting forthe root with the bacteria. So, youre just upping the frequency of sure, Leach says. some event that you know needs to happen with or without you. DECEMBER 2024SEEDWORLD.COM /87'