How plant architectures mimic subway networks

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It might seem like a tomato plant and a subway system don’t have much in common, but both, it turns out, are networks that strive to make similar tradeoffs between cost and performance.

Using 3D laser scans of growing plants, Salk scientists found that the same universal design principles that humans use to engineer networks like subways also guide the shapes of plant branching architectures. The work, which appears in the July 26, 2017, issue of Cell Systems, could help direct strategies to increase crop yields or breed plants better adapted to climate change.

It might seem like a tomato plant and a subway system don’t have much in common, but both, it turns out, are networks that strive to make similar tradeoffs between cost and performance.

Using 3D laser scans of growing plants, Salk scientists found that the same universal design principles that humans use to engineer networks like subways also guide the shapes of plant branching architectures. The work, which appears in the July 26, 2017, issue of Cell Systems, could help direct strategies to increase crop yields or breed plants better adapted to climate change.

“The idea for this work really started with an engineering question,” says Saket Navlakha, assistant professor in Salk’s Center for Integrative Biology and senior author of the paper. “How do transportation networks like a subway system or an electric grid resolve the tension between two competing objectives, such as cost and performance? And do plants resolve similar competing objectives in the same way?”

Engineered transportation networks, whether for moving people or power, need to balance the cost of construction with providing efficient transport. Think of a subway system: If the main objective when designing it is to get people from the suburbs to downtown as quickly as possible, each suburb will have its own direct line to downtown. But that would be prohibitively expensive to build. Conversely, if the only objective is to limit cost, there would be very few lines, and it would take a long time for some riders to reach downtown. Thus, the engineering challenge is to find some balance of these two objectives. If you extend this analogy to a plant, its base is like downtown and its leaves are like the suburbs. Nutrients need to get between these areas as quickly as possible, while limiting the cost of growing extraneous branches.

Continue reading at Salk Institute

Image: Salk Institute scientists find that plants and subway systems are both networks that strive to make similar tradeoffs between cost and performance.  Credit: Salk Institute