Dr Michelle Dickinson: nanotechnologist on where potatoes came from

Did you know that the humble potato owes its very existence, and its global success as a food staple to an ancient genetic mash-up? 

A recent study in the journal Cell of over 100 wild and cultivated potato genomes has revealed a fascinating secret about the potato family tree. 

The beloved spud and its 107 wild relatives all belong to a plant group called Petota. What sets Petota apart is its ability to grow underground tubers, the very organs we eat. 

But where did this tuber-making trait come from? 

Turns out, millions of years ago, two very different wild plant lineages, one similar to tomatoes and another that doesn’t make tubers at all crossed paths. 

Somewhere in the high mountains of South America, their genetic material combined through hybridization, creating a brand-new lineage: Petota. This ancient hybrid inherited just the right mix of genes to develop tubers, enabling these plants to store nutrients underground and survive tough climates. 

Scientists now believe that this innovative tuber-forming ability helped Petota rapidly diversify into over 100 species, adapting to everything from dry tropical forests to cold, high-altitude meadows. In fact, this ancient hybrid lineage shows faster species evolution than its parent lineages, highlighting how powerful hybridization can be in driving plant diversity. 

Even more impressive? The very genes responsible for making tubers like SP6A and IT1 were inherited from each parent in a sort of genetic collaboration. Modern genetic experiments show these hybrid genes are essential for tuber development and are still active in today's potatoes. 

So, next time you mash, bake, or roast a potato, remember it’s not just a vegetable. It’s the product of an ancient botanical tomato love story that changed the course of agricultural history. 

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Episode Transcript

Speaker 1 (00:06):
You're listening to the Sunday Session podcast with Francesca Rudgin
from News Talks.

Speaker 2 (00:11):
It'd be joining me now with her science study of
the week, Doctor Micheldeck and Sin Good morning, Good morning.

Speaker 3 (00:17):
Okay.

Speaker 2 (00:17):
Now I often tell you how much I learned from
the science studies that you bring in, but today my
mind has been blown. I had no idea about the
origins of the potato.

Speaker 3 (00:26):
Do you know what? Nor did I, and apparently Nor
died the rest of the world. That's what I love
about scientific research. So if you want to read this,
it's in their journal Cell and it's a whole study
figuring out where the potato came from. And I'm going
to omit when I eat my chips. I don't really
think about this, but if I had a guessed, I
would never have thought the potato came from the tomato. No,

(00:47):
but that's what this study found. So what happened is
researchers analyze four hundred and fifty different types of cultivated
potato as well as fifty six wild species of potatoes,
and they've basically genetically analyzed it to figure out nine
million years ago that two very different wild plant lineages,
one which is similar to a tomato that we know today.

(01:09):
And the other one, which is called a I think
you pronounce it ou tuberosu etu b e r O
s u m, which is a type of plant that
does not make tubers but looks a bit like a
potato plant at the top, came together somewhere in the
high mountains of South America, and their genetic material combined

(01:31):
through something called hybridization, and they created a brand new lineage,
which is called a potota. And this ancient hybrid inherited
just the right amount of genes from both sides that
it actually switched on the genes that we needed to
develop tubers, and the tuber is the part of the
potato that we eat, So that allowed the plants to

(01:51):
straw nutrients underground and survive in tough climates and for
us to then harvest that nutrient rich tuber which is
what we eat today as the potato.

Speaker 2 (02:03):
I feel like it's just the beginning of the story, Michelle,
Like it's all one. It's like usene want to know
how it's traveled the world and how it's kind of
taken hold and things like that.

Speaker 3 (02:12):
Oh totally. So the thing in this story. That's interesting
is they were able to identify the very specific genes,
so they're called SP six A and IT one, and
they were inherited from each parent in sort of this
genetic collaboration. And what they found is that actually even
modern genetic experients show that these two hybrid genes are
essential even today for tuba development and still active in

(02:36):
today's types of potatoes. So that weird hybrid idation that
happened nine million years ago is literally why we have
like the world's most important staple food that feeds so
many of us. And when you think about how these
different you know, we've got all sorts of different types
of potatoes and styles and types of traveled the world.
But actually, if you think about global food security and

(02:58):
we know we've got a huge issue around increasing population,
climate is changing, blah blah blah, I think the potato
is going to be the thing that keeps us all alive.
And so this research is really important for us to understand, well,
number one, could we turn these genes onto other types
of plants to create other nutrient rich types of plants
that we can eat, But also how do we improve

(03:20):
our current crops to be more resistant to some of
the challenges that we know that we're going to have
on our planet. So this didn't go into how they
traveled the world, but it did go into how they
all then went off and created their other different things.

Speaker 2 (03:32):
That's just my imagination.

Speaker 3 (03:33):
It's well, we can do that next week. But yeah,
if you've ever had a potato this week and gone, oh,
I wonder where that came from, I bet you didn't
guess tomato.

Speaker 1 (03:43):
Sure do.

Speaker 2 (03:44):
Thank you so much, Michelle. We'll catch up next.

Speaker 1 (03:46):
Week for more from the Sunday session with Francesca Rudken.
Listen live to use talks. It'd be from nine am Sunday,
or follow the podcast on iHeartRadio.