Amir Motmaen

I spent two weeks in the laboratory with @NickDesnoyer and he taught me how to “paint” flowers. I would literally dip a brush into an Eppendorf tube containing a clear liquid, then lightly tap it against white, floral buds that hadn’t opened yet. At first, I thought this was extremely weird. I definitely did not think the flowers would change, because I had barely touched them with this liquid. But when we came back the next day, the buds had opened and were a mottled mix of white and pink. Everywhere I had touched the petals with the liquid — containing a molecule called dexamethasone — the cells had turned purple. You could actually see the color spreading along the veins as the molecule moved through the petals. Wherever it reached cells, it switched on an introduced gene that activated pigment production. We were, in other words, painting flowers by turning genes on, using small molecule inducers. Now Nick is taking this strain of petunia and adding two more inducible genes so he can turn on yellow and cyan pigments, too. The idea is that you could basically do CMYK printing on flowers. If you touch two different small-molecule inducers to the same part of a petal, you'd switch on both genes and thus get a blend of colors. The whole interview is filled with thought-provoking stuff, which feels weird and egotistical to say because it’s my podcast. But talking to Nick about flower design completely opened my eyes to the breadth of what biotechnology can do. We’re so used to thinking about therapeutics and binders and small molecules, but if you zoom out and look at how nature uses genetic diversity to create new functions, you start to see how evolution creates these interactions that can be exploited to build new functions. Nick is basically just observing those functions, finding the genes behind them, and moving them into flowers to get the effects he wants. All of this is created by repurposing genes that already exist in nature.