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are embedded in living leaves rather than mixed in stainless
steel vats. But how exactly does that happen? How do we
go from a DNA sequence on a screen to a salad that treats
disease?

Step 1: Designing the Blueprint

The process begins with a gene—the digital blueprint for a
therapeutic protein. Think of it as a biological instruction
manual: a precise sequence of nucleotides that, when
decoded by a cell, leads to the construction of a molecule
with a specific function. That function might be
enzymatic—like breaking down a toxic amino acid in a rare
metabolic disorder. It might be defensive—like binding to a
virus and blocking infection. Or it might be immunologic—
like gently nudging the immune system toward tolerance
rather than attack.

But finding the right gene is only the first step. Human
DNA is written in a dialect that plant cells don’t naturally
speak. So before the gene can be introduced into a leaf, it
must be translated—not in the biological sense, but in
the bioengineering one. This is where synthetic biology
enters the scene.

The gene is chemically synthesized from scratch—
custom-built for the plant host that will express it. That
means optimizing the codon usage (the three-letter words
that make up proteins) to match the preferences of plant
ribosomes. It means stabilizing the mRNA structure to
avoid degradation. It means anticipating the cellular
environment—acidic or basic, cytoplasmic or
chloroplastic—and designing the gene so its protein
product will fold properly and function effectively in that
context.

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