
Scientists Have 'Hacked Photosynthesis' in Search of More Productive Crops - evo_9
https://www.npr.org/sections/thesalt/2019/01/03/681941779/scientists-have-hacked-photosynthesis-in-search-of-more-productive-crops
======
tomxor
I wonder - once we start replacing more extensive segments that represent
complex functions, not only does it become a less probable natural solution
but to steal a term from ML - perhaps there is a danger of temporal "over-
fitting"... The natural version maybe sub-optimal in the current climate, but
that historical baggage could have evolved to that state because it allowed
the continuation of that species through a more diverse range of climates,
something that could be useful in the future.

There is the potential that forcing a "more efficient" solution for _now_,
could be also creating a more fragile and endemic species? Perhaps not even
for the distant future, if details in the original in-fact make it better able
to cope with subtle climatic variations more efficiently.

~~~
sampo
Crop plants and livestock animals are already pretty much unable to survive in
the wild, outside of farms. So the "overfitting" is as old as farming.

~~~
tomxor
True, but this is direct, cultivation is by proxy, and does not necessarily
remove unexpressed genes.

~~~
n4r9
That's a confusing thing to say... surely GMO doesn't necessarily remove
unexpressed genes either?

To provide a counterargument, with GMO we additionally have a decent
understanding of the underlying mechanics and which genes have changed. This
puts us in a better position to correct things if they do turn out to have
unintended consequences.

~~~
tomxor
> That's a confusing thing to say... surely GMO doesn't necessarily remove
> unexpressed genes either?

You may be correct, this was speculation based on imagination on my part - I
do not know if unexpressed genes were removed in this experiment, I only have
a suspicion they may have been part of the "inefficient" original sequence
that was replaced.

------
TheBeardKing
>"But it has what we like to call one fatal flaw," Cavanagh continues.
Unfortunately, Rubisco isn't picky enough about what it grabs from the air. It
also picks up oxygen. "When it does that, it makes a toxic compound, so the
plant has to detoxify it."

Can someone explain this, the article doesn't go into much detail. What is
this toxic compound, and why must the plant make it?

edit: Explained in detail in this article:
[https://arstechnica.com/science/2019/01/re-engineering-
photo...](https://arstechnica.com/science/2019/01/re-engineering-
photosynthesis-gives-plants-a-40-growth-boost/)

~~~
jessriedel
The semi-technical "Perspective" column

[http://science.sciencemag.org/content/363/6422/32](http://science.sciencemag.org/content/363/6422/32)

in the same issue of Science is also excellent while still being more
accessible than the main technical article.

[http://science.sciencemag.org/content/363/6422/eaat9077](http://science.sciencemag.org/content/363/6422/eaat9077)

------
dreen
The article focuses on GMO food production which is great. But since this
process is said to be more efficient than the natural one, could this be also
used for consuming the excess carbon dioxide in our air?

~~~
thinkcontext
A field crop planted annually that grows faster or bigger isn't likely to make
much of a difference to atmospheric CO2 as it will just release it again after
harvest. Perennial plants (those that don't need to be planted each year) are
better at sequestering CO2 in the soil, along with other benefits. The Land
Institute does work on this, including developing (through traditional plant
breeding) a perennial wheat variety which is being trialed [0].

There are other agricultural practices that promote CO2 sequestration in the
soil. You might have a look at Project Drawdown, it ranks solutions to climate
change based on impact and has a section on food [1] which includes
agricultural solutions. For example, Silvopasture [1], ranked #9 overall
amongst all solutions, involves integrating trees with livestock pasture.
Another one is conservation agriculture (#16) which uses annual crops but
promotes soil health in selection of species and method and timing of planting
[3].

[0] [https://landinstitute.org/our-work/perennial-
crops/](https://landinstitute.org/our-work/perennial-crops/)

[1]
[https://www.drawdown.org/solutions/food](https://www.drawdown.org/solutions/food)

[2]
[https://www.drawdown.org/solutions/food/silvopasture](https://www.drawdown.org/solutions/food/silvopasture)

[3] [https://www.drawdown.org/solutions/food/conservation-
agricul...](https://www.drawdown.org/solutions/food/conservation-agriculture)

~~~
mrfusion
Why can’t you take all the leftover biomass after a harvest and sequester it?
Then it wouldn’t “simply relaase it”. I’d image we only take a small part of
the mass for food.

~~~
Maximus9000
for which crop? most of the leftover biomass is used in typical crops.

For corn, the stalks are used as silage. For wheat, the stalks are used to
make straw.

~~~
weberc2
> For corn, the stalks are used as silage.

How common is this? In my area, the combines chew up the stalks and spit them
out as chaff. I don't see many people collecting the chaff.

~~~
Maximus9000
Not sure. The dairy farm I worked at used the corn stalks. They make a product
called "silage" which can be used as winter feed for the cattle.

~~~
weberc2
Curious. My neighbor was a dairy farmer. They did this too. No one else
though.

~~~
Juggerbot
It can depend on the price of fodder. If hay is cheap, there's not much
incentive to spend time/fuel on baling stalks.

However, if they're not baled, they decompose in the field, which technically
reduces fertilizer inputs.

------
mdf
There’s a website for a project aiming to produce a modified version of rice
using these improved photosynthesis pathways[1]. Some previous HN discussion
on the subject can also be found[2]. Really interesting stuff!

[1] [https://c4rice.com/](https://c4rice.com/)

[2]
[https://news.ycombinator.com/item?id=8867365](https://news.ycombinator.com/item?id=8867365)

------
antepodius
I hate the writing in this. "This protein's super-important!" "Yay for
Rubisco!"

~~~
sp332
Here [https://arstechnica.com/science/2019/01/re-engineering-
photo...](https://arstechnica.com/science/2019/01/re-engineering-
photosynthesis-gives-plants-a-40-growth-boost/)

~~~
TheBeardKing
Thanks for sharing, this article is so much better than OP's. It answers a
question I posted which the NPR article was very vague on, but Ars covers in
detail.

------
rmason
While this is certainly interesting it doesn't have as wide an application as
you might think. In tobacco the harvested product of value is in the leaves,
bigger leaves means a bigger crop.

But take corn, larger leaves and a taller plant doesn't result in bigger ears
of corn. A taller plant in general means that it is more likely to lodge or
fall down in the fall before it's harvested. Some corn is harvested as silage
meaning the entire plant is chopped and fed to cows. I've worked with farmers
who experimented with varieties of corn that would be 3-4 feet taller than
regular corn. The result was less feed value per acre than what they had been
growing.

With soybeans, wheat or oats you can also likely get an increased amount of
disease with more foliage. This development may see more application than just
tobacco but it remains to be seen.

~~~
jessriedel
This is a modification which increases the efficiency with which the plants
generate needed sugars which presumably are used everywhere in the plant, not
just the leaves. Why would this only increase the size of leaves?

Indeed, if each photosynthesizing leaf becomes more efficient, wouldn't this
_decrease_ the number of leaves you need to support the non-leaf consumable
part of the plant, allowing foliage to _decrease_?

------
rdlecler1
In nature there is typically no free lunch. Optimizing this may lead to other
issues such as lower drought tolerance of less natural pesticide resistance.
Although as the author states, photosynthesis isn’t usually a rate limiting
factor in nature so it could potentially be optimized.

------
pillow-case
It's neat to see this finally come to fruition (no pun intended). Someone has
been anonymously posting about this research for the last few years on 4chan's
science board.

------
rdiddly
_" It's called Rubisco, which is short for an actual chemical name that's very
long and hard to remember."_

Anybody else wish he would've let us be the judge of that?

[https://en.wikipedia.org/wiki/RuBisCO](https://en.wikipedia.org/wiki/RuBisCO)

------
seeker61
Superweeds have been talked about before, in terms of weeds that are herbicide
resistant. Kind of a yawn, really, unless you're a farmer.

But a weed that grows 40% faster than anything else out there? That's some
scary stuff. (Palmer amaranth, for example)

~~~
jandrese
Kudzu?

Anyway, my impression is that most plants bottleneck on water or nutrients
before sunlight, so this probably won't make that big of an impact if it gets
out in the wild, but it would be a problem on fertilized and irrigated fields.

------
peter303
Also for better solar batteries. Direct solar to dissociated hydrogen &
oxygen. Might eventually be more efficient than solar generated electricity if
you read some of the university press releases.

------
jelliclesfarm
There isn’t enough information to assess why this is a good thing or if it
will work.

------
rubyfan
What could possibly go wrong?!

~~~
Majestic121
A lot of things can go wrong for pretty much any significant technology.

Those technologies do require caution, and control, but I think this is still
a good step forward, even if it ends up being unusable as is for whatever yet
unforeseen reason.

------
Analemma_
One thing that concerns me about hacking crops to have higher yields is that
they may consume more soil nutrients, when we’re already in pretty serious
danger of exhausting large patches of arable land. So then we’d need to use a
lot more fertilizer, which is already an environmental disaster at its current
scale with nitrogen/phosphate runoff.

There’s no such thing as a free lunch, unfortunately.

