Paclitaxel is a compound
that can treat cancer.
Salicylic acid reduces
headaches and fevers.
Carotenenoids can
turn your skin orange.
And miraculin changes
your sense of taste.
What do all of these awesome
compounds have in common?
They all come from plants.
[MUSIC PLAYING]
More than 100,000 natural
compounds occur in plants,
and we've barely explored them.
These small molecules
are called metabolites.
Just like all the
DNA in an organism
forms the genome, all
of the metabolites form
the metabolome.
Even though each metabolite can
be made from only six elements,
there are so many
possibilities that it
would take scientists thousands
of years to make each one
and figure out its usefulness.
Luckily, plants have
already done this for us.
Plants have the disadvantage
of being rooted to the ground.
So over time, they've
trialed and errored,
making lots of compounds
to see which ones help
them survive and thrive best.
And because they've
been interacting
with other species like us for
hundreds of thousands of years,
some of their chemicals turn
out to be really useful,
both inside and
outside our bodies.
But to use plants to
their full potential,
we have to know what
chemicals they make
and how they make them.
Instead of studying
every chemical one
by one, what if we could
study all of them at once?
We can start by mapping
the huge network that
connects metabolites.
In any living
organism, molecules
are always on the move,
being converted and shuttled,
decomposed, and filled
back up again and reused.
It's just like a subway system,
except in biology the people
are the chemicals, and
the train is the enzyme
that converts and moves them.
If you look at a
city from above,
how could you map the
whole subway system?
Similarly, if we
look at a plant,
how can we figure out the
entire metabolome network?
To figure out a path in the
system, what we actually
need to do is break it.
If we mutate or
disrupt a pathway
and see how the metabolite
quantities change,
we can figure out the
connections between them.
Let's say the train from
Central to MIT breaks.
We wouldn't see students
arriving at MIT,
and would instead see them
building up at Central.
But not only that, anyone else
traveling along the Red Line
would also be affected.
So it's the
redistribution of people
which reveals the
Red Line subway path
and tells us where
the train broke.
We can use this
system's thinking
to uncover the plant
metabolite network.
For example, we
know that a compound
called sinapoyl malate, which
protects the plant from UV
damage by interacting
with UV light,
making the plant glow green.
And without it, the
plant would glow red.
So if we see a red plant,
it's like seeing no people
at the sinapoyl malate station.
But we wouldn't yet know
where the train broke
or what other stations
are along the route.
To do that, we can mutate
a lot of the seeds,
plant them, and
choose the red ones.
[MUSIC PLAYING]
Now, we can analyze
these samples
by using the mass spectrometer.
It measures how much
of each metabolite
is present in the sample.
Then we can use a
program to see which
compounds are effective and
map that part of the network.
It's like revealing
the Red Line.
Once we figure out how the
entire metabolome works,
we can use it to engineer plants
to create new biomaterials,
medicines, and clean energy.
We might even discover
that plants have
the secret to living forever.
We just need to unlock
their chemical mysteries.
[MUSIC PLAYING]
