8 ms·

The Plan to Feed the World by Hacking Photosynthesis

57 points by Blahah 11y ago

Blahah 11y ago
I'm working on one of these projects, trying to make C4 photosynthesis an installable module. Happy to answer questions.
- seszett 11y ago
  Are C3 and C4 really simply interchangeable mechanisms? What about CAM, would it be possible to "install a CAM module" into maize to make it drought resistant, though less productive? Also, but that might not be directly related to your work, the article says "plants already absorb more sunlight than they can use" but still goes on to talk about how they could be more efficient if they used a larger part of the light spectrum. Would it serve any purpose, then?
  - Blahah 11y ago
    You can think of C3, C4 and CAM as interchangeable functions, yes. They take in CO2 and energy from sunlight, and they output sugar: def photosynthesis(co2, energy) # C3, C4 or CAM return sugar end to your second question, plants absorb photons that are not converted to biomass because all the light harvesting machinery is saturated. But this is only true at the parts of the plant that are most exposed to light. The idea is that we could reduce the absorption in those parts and let some light through to other parts of the plant, where it could be absorbed at a different wavelength if we install that ability.
    - pvaldes 11y ago
      Maybe interchangeable is not the right word here (defun edible.in.large.amounts? (plant) (if (equal plant "CAM-plant") (print "Not, unless you really know what are doing")))
- murbard2 11y ago
  I was under the impression that nitrogen fixation was still the limiting factor in plant growth. If that's the case, will improving photosynthesis really improve yields?
  - afarrell 11y ago
    I'm a vast gaping maw of ignorance here, but I thought we had solved nitrogen fixation with the fritz-Haber process at the cost of using fossil fuels. Am I wrong, or are we just trying to keep farmers from having to buy ammonium nitrate?
    - murbard2 11y ago
      What I've been told is that, while fertilizers obviously help a lot, they aren't a panacea and the plant still needs to do some expensive nitrogen chemistry which will set limits to its growth, regardless of how much energy it gets from photosynthesis.
    - Blahah 11y ago
      Supplementing nitrogen comes with a whole host of environmental trade-offs. In particular there are problems with pollution, where nitrogen added to fields gets washed off in the rain and ends up in waterways. There it can totally destabilise ecosystems by introducing a flood of nitrogen which is usually a scarce resource, leading to massive population explosions of some kinds of organisms, which in turn can leave huge buildups of toxic byproducts. This is called eutrophication. https://en.wikipedia.org/wiki/Eutrophication https://en.wikipedia.org/wiki/Eutrophication
  - Blahah 11y ago
    Yes, it will. Plants need nitrogen to make proteins, and the most abundant protein in plants is RuBisCO - the one that fixes CO2 in the air into carbohydrates to store the energy from sunlight. Most plants have to produce a vast amount of RuBisCO to make up for the fact that photosynthesis is so inefficient. By making it more efficient, we reduce the amount of RuBisCO needed and therefore reduce the nitrogen required. C4 plants are much more nitrogen efficient than C3 plants.
- david-given 11y ago
  Would improved photosynthesis be liable to find its way into nearby weeds via horizontal gene transfer? It sounds like a really advantageous modification, and so something that's likely to be picked up on. (Whereas, say, a modification for higher yields wouldn't be, because it wouldn't be advantageous for a weed.)
  - Blahah 11y ago
    I think this is extremely unlikely. This is because the engineering projects we are talking about involve co-ordinating the regulation of dozens of genes (at least 40 in my project). To build the system we have to transfer in the components separately in many different plants and then carefully stack the changes using breeding techniques. The probability of this happening in nature would be infinitessimally small, especially because we have found that by taking only some of the changes you actually get a decrease in photosynthesis.
Thiz 11y ago
I believe the answer is not in agriculture but in nanofoods. The ability to produce food from manipulating basic elements. But for that we need to tame energy first, then water, then food.
- innguest 11y ago
  If we ever get to tame energy I don't think we'll need to care about water and food. It seems inefficient to tame energy only to then invest more time in food research to give our bodies energy.
- mattzito 11y ago
  There's also, I fear, a trap here where we believe we understand nutrition, only to discover there are nuances that we still don't have a great handle on. As an example, there's the emerging posibility that one's gut flora can have a huge impact on overall health - and that certain types of foods can have a negative or positive impact on that gut flora. Manipulating basic elements could easily lead to our skipping over critical parts of our health needs, with unintended consequences down the line. Put another way: our dietary habits and nutritional systems developed over tens-to-hundreds of thousands of years. I'm very leery of any theory that we can easily replace that.
  - tudorw 11y ago
    Right, gladly I believe we are some way beyond 'emerging' and into 'researching' , 'This year, the US National Institute of Mental Health spent more than US$1 million on a new research programme aimed at the microbiome–brain connection.' http://www.nature.com/news/gut-brain-link-grabs-neuroscientists-1.16316 http://www.nature.com/news/gut-brain-link-grabs-neuroscienti...
- thechao 11y ago
  I'll use an analogy with "nanorobots": When I was doing nanotech 10+ years ago, and people asked me when nanorobots were coming, I'd always ask them why they thought nanorobots would be different than, say, bacteria, or viruses? The constraints "at the bottom" (as Feynman would say) are quite high—and we're not really very close to being able to engineer at that scale. Heck, even making a robot the size of a grain of rice is a pretty daunting task, and a nanorobot would be built on a scale that's 10^12 to 10^18 times smaller (the cubic relationship is a real bitch), depending on what you mean by "nanoscale". Engineering a "thing" to convert basic chemicals and sunlight into food is a pretty significant task. While I would bet that plants are nowhere near close to optimal, they're already solving the problem. Changing & rethinking an existing system is far easier than simply creating one from whole cloth. If I had to guess, I'd say that "producing food from manipulating basic elements" using a piece of tech entirely designed by human hands, from scratch, is at least a couple of centuries in the future.
balabaster 11y ago
Naive questions (largely because this is a whole area of science I'm ignorant to, but I am curious): If plants could benefit from more efficient photosynthesis, over the span of the billions of years they've been doing it, wouldn't they have evolved to do so? Sure, it may benefit us in some way to assist, but how does the plant benefit? The fact they're green and not other colors could be a significant evolutionary advantage... or wouldn't we expect to see other a large diversity of other colour plants? Why did green win out and not some other colour that absorbs different areas of the light spectrum? If one of the laws of nature is survival of the fittest, what do we humans know that makes us think that our ability to tinker with evolution without negative consequences is a wise decision?
- mkaziz 11y ago
  To your last point: Evolution is prone to local maximums. We evolved to think beyond them.
  - astazangasta 11y ago
    You're talking about a "local maximum" sustained over half a billion years and trillions of organisms. It's much more likely that this is just optimal for plants.
    - balabaster 11y ago
      Exactly - if an infinite number of monkeys sat typing at an infinite number of typewriters, eventually, one would produce the entire works of Shakespeare...
    - oldmanjay 11y ago
      That's a logical fallacy on its face given the nature of evolution. If there is no pressure to improve then there is no reason for an improvement to take hold, but that in no way implies that a given mechanism is perfected along any access, just good enough.
- murbard2 11y ago
astazangasta 11y ago
I'll make a complaint on the way this article is written which I think is quite damaging: the sense that all of this work is being done by "scientists" and "experts" who will develop this technology in their ivory towers and make it available to the public at some point. Just wait around and you will be handed these gifts. This style sucks because it separates the reader from "experts" (you are not one), and it implies that you cannot participate even by intent. Experts will decide what is best for you, and you must receive it and like it. The notion that the future is something produced by a few and the majority only receive it passively is an affront to a free society.
- maaarghk 11y ago
  I'm pretty confused by your logic, I certainly don't think that it implies, for example, that the reader would be unable to go into education and go down a career path where they would become one of the few experts who are working in this field. It even links to papers and technical articles.
- mohaine 11y ago
  I'm assuming that is because this future WILL be created by experts. That isn't elitist, but if you want to help you will have to put in the time an effort to became an export.
legulere 11y ago
Producing enough food is basically a solved problem, distribution and hindering people to eat an everincreasing amount of meat is the problem
- Blahah 11y ago
  This is partly true, but is not helpful. The goal is for nobody to go hungry. By increasing crop yields in the most common staple crops, we have a clear technological engineering problem to solve and various ways to approach it, all achievable. This allows more food to be produced more cheaply in the areas that need it most. If we refuse to produce more food until the food that is already produced is distributed evenly, many people will die or go hungry because the socio-political problems are very complex. There is no engineering solution to them in sight. By all means let's try to solve problems of inequality. But let's also try to feed people as soon as possible by whatever means are available.
  - marktangotango 11y ago
    Feeding the world isn't a tech problem, it's a public policy problem. Blows my mind how little people know about this.
    - Blahah 11y ago
      It is clearly both, which is what I said above. Synchronising the entire global economy is harder and less tractable than engineering photosynthesis, so we should be working on both (which is exactly what we are doing).
- briantakita 11y ago
  Monoculture, petrol, chemical agriculture is often produced in a centralized manner, which introduces inefficiencies (with environmental issues) in transport, fertilization, pest control, etc. The current paradigm also requires large amounts of capital to purchase machinery, mined fertilizer, poisonous pesticides, GMOs where seeds can't be saved, etc. This cycle of dependence has caused many small farms to be in financial crisis. Also, don't forget that large scale factory farming is subsidized by the government. Without these subsidizations, large scale factory farming is not viable. Factory meat production follows the same pattern of monoculture, with disgusting & unhealthy results. The alternative is to decentralize food production. Small, organic, polyculture farms reduce or eliminate the need to transport food over long distances, import fertilizer, use pesticides. Decentralized food production also enables the farmer to be independent of having to purchase expensive inputs from large multinational corporations. Small farms are more humane and, similar to startups, freer to innovate.
briantakita 11y ago
“Problems cannot be solved with the same mind set that created them.” ― Albert Einstein There are more natural ways to achieve the same results. Perennial Polycultures use natural flora & fauna in a closed loop ecosystem. They also have higher overall yields than monocultures. These solutions are available to us right now. In fact there's a growing movement of farmers who are utilizing & learning more about Perrenial Polycultures. Here is some literature: http://www.amazon.com/The-One-Straw-Revolution-Introduction-Classics/dp/1590173139 http://www.amazon.com/The-One-Straw-Revolution-Introduction-... http://www.edibleforestgardens.com/about_book http://www.edibleforestgardens.com/about_book http://www.afforestt.com/index.html http://www.afforestt.com/index.html Here are some farms that I'm familiar with (either I know the farmers or they are well known): http://www.newforestfarm.net/ http://www.newforestfarm.net/ http://www.polyfacefarms.com/ http://www.polyfacefarms.com/ http://www.fieldswithoutfences.org/ http://www.fieldswithoutfences.org/ http://www.thevitalfarm.com/ http://www.thevitalfarm.com/
pvaldes 11y ago
There are some problems with plants, and one of them is that plants are, often misunderstood, live beings that are strategist by nature. If you put an improved photosyntesis in rice, this could lead to more grain of course, but also could boost the production of leaves and roots and the result could be less or none grain in the same time. Or atract predators. Have you consider this possibilities?

57 points by Blahah 11y ago

I'm working on one of these projects, trying to make C4 photosynthesis an installable module. Happy to answer questions.

seszett 11y ago
Are C3 and C4 really simply interchangeable mechanisms? What about CAM, would it be possible to "install a CAM module" into maize to make it drought resistant, though less productive? Also, but that might not be directly related to your work, the article says "plants already absorb more sunlight than they can use" but still goes on to talk about how they could be more efficient if they used a larger part of the light spectrum. Would it serve any purpose, then?
- Blahah 11y ago
  You can think of C3, C4 and CAM as interchangeable functions, yes. They take in CO2 and energy from sunlight, and they output sugar: def photosynthesis(co2, energy) # C3, C4 or CAM return sugar end to your second question, plants absorb photons that are not converted to biomass because all the light harvesting machinery is saturated. But this is only true at the parts of the plant that are most exposed to light. The idea is that we could reduce the absorption in those parts and let some light through to other parts of the plant, where it could be absorbed at a different wavelength if we install that ability.
  - pvaldes 11y ago
    Maybe interchangeable is not the right word here (defun edible.in.large.amounts? (plant) (if (equal plant "CAM-plant") (print "Not, unless you really know what are doing")))
murbard2 11y ago
I was under the impression that nitrogen fixation was still the limiting factor in plant growth. If that's the case, will improving photosynthesis really improve yields?
- afarrell 11y ago
  I'm a vast gaping maw of ignorance here, but I thought we had solved nitrogen fixation with the fritz-Haber process at the cost of using fossil fuels. Am I wrong, or are we just trying to keep farmers from having to buy ammonium nitrate?
  - murbard2 11y ago
    What I've been told is that, while fertilizers obviously help a lot, they aren't a panacea and the plant still needs to do some expensive nitrogen chemistry which will set limits to its growth, regardless of how much energy it gets from photosynthesis.
  - Blahah 11y ago
    Supplementing nitrogen comes with a whole host of environmental trade-offs. In particular there are problems with pollution, where nitrogen added to fields gets washed off in the rain and ends up in waterways. There it can totally destabilise ecosystems by introducing a flood of nitrogen which is usually a scarce resource, leading to massive population explosions of some kinds of organisms, which in turn can leave huge buildups of toxic byproducts. This is called eutrophication. https://en.wikipedia.org/wiki/Eutrophication https://en.wikipedia.org/wiki/Eutrophication
- Blahah 11y ago
  Yes, it will. Plants need nitrogen to make proteins, and the most abundant protein in plants is RuBisCO - the one that fixes CO2 in the air into carbohydrates to store the energy from sunlight. Most plants have to produce a vast amount of RuBisCO to make up for the fact that photosynthesis is so inefficient. By making it more efficient, we reduce the amount of RuBisCO needed and therefore reduce the nitrogen required. C4 plants are much more nitrogen efficient than C3 plants.
david-given 11y ago
Would improved photosynthesis be liable to find its way into nearby weeds via horizontal gene transfer? It sounds like a really advantageous modification, and so something that's likely to be picked up on. (Whereas, say, a modification for higher yields wouldn't be, because it wouldn't be advantageous for a weed.)
- Blahah 11y ago
  I think this is extremely unlikely. This is because the engineering projects we are talking about involve co-ordinating the regulation of dozens of genes (at least 40 in my project). To build the system we have to transfer in the components separately in many different plants and then carefully stack the changes using breeding techniques. The probability of this happening in nature would be infinitessimally small, especially because we have found that by taking only some of the changes you actually get a decrease in photosynthesis.

Thiz 11y ago

I believe the answer is not in agriculture but in nanofoods. The ability to produce food from manipulating basic elements. But for that we need to tame energy first, then water, then food.

innguest 11y ago
If we ever get to tame energy I don't think we'll need to care about water and food. It seems inefficient to tame energy only to then invest more time in food research to give our bodies energy.
mattzito 11y ago
There's also, I fear, a trap here where we believe we understand nutrition, only to discover there are nuances that we still don't have a great handle on. As an example, there's the emerging posibility that one's gut flora can have a huge impact on overall health - and that certain types of foods can have a negative or positive impact on that gut flora. Manipulating basic elements could easily lead to our skipping over critical parts of our health needs, with unintended consequences down the line. Put another way: our dietary habits and nutritional systems developed over tens-to-hundreds of thousands of years. I'm very leery of any theory that we can easily replace that.
- tudorw 11y ago
  Right, gladly I believe we are some way beyond 'emerging' and into 'researching' , 'This year, the US National Institute of Mental Health spent more than US$1 million on a new research programme aimed at the microbiome–brain connection.' http://www.nature.com/news/gut-brain-link-grabs-neuroscientists-1.16316 http://www.nature.com/news/gut-brain-link-grabs-neuroscienti...
thechao 11y ago
I'll use an analogy with "nanorobots": When I was doing nanotech 10+ years ago, and people asked me when nanorobots were coming, I'd always ask them why they thought nanorobots would be different than, say, bacteria, or viruses? The constraints "at the bottom" (as Feynman would say) are quite high—and we're not really very close to being able to engineer at that scale. Heck, even making a robot the size of a grain of rice is a pretty daunting task, and a nanorobot would be built on a scale that's 10^12 to 10^18 times smaller (the cubic relationship is a real bitch), depending on what you mean by "nanoscale". Engineering a "thing" to convert basic chemicals and sunlight into food is a pretty significant task. While I would bet that plants are nowhere near close to optimal, they're already solving the problem. Changing & rethinking an existing system is far easier than simply creating one from whole cloth. If I had to guess, I'd say that "producing food from manipulating basic elements" using a piece of tech entirely designed by human hands, from scratch, is at least a couple of centuries in the future.

balabaster 11y ago

Naive questions (largely because this is a whole area of science I'm ignorant to, but I am curious): If plants could benefit from more efficient photosynthesis, over the span of the billions of years they've been doing it, wouldn't they have evolved to do so? Sure, it may benefit us in some way to assist, but how does the plant benefit? The fact they're green and not other colors could be a significant evolutionary advantage... or wouldn't we expect to see other a large diversity of other colour plants? Why did green win out and not some other colour that absorbs different areas of the light spectrum? If one of the laws of nature is survival of the fittest, what do we humans know that makes us think that our ability to tinker with evolution without negative consequences is a wise decision?

mkaziz 11y ago
To your last point: Evolution is prone to local maximums. We evolved to think beyond them.
- astazangasta 11y ago
  You're talking about a "local maximum" sustained over half a billion years and trillions of organisms. It's much more likely that this is just optimal for plants.
  - balabaster 11y ago
    Exactly - if an infinite number of monkeys sat typing at an infinite number of typewriters, eventually, one would produce the entire works of Shakespeare...
  - oldmanjay 11y ago
    That's a logical fallacy on its face given the nature of evolution. If there is no pressure to improve then there is no reason for an improvement to take hold, but that in no way implies that a given mechanism is perfected along any access, just good enough.
murbard2 11y ago

astazangasta 11y ago

I'll make a complaint on the way this article is written which I think is quite damaging: the sense that all of this work is being done by "scientists" and "experts" who will develop this technology in their ivory towers and make it available to the public at some point. Just wait around and you will be handed these gifts. This style sucks because it separates the reader from "experts" (you are not one), and it implies that you cannot participate even by intent. Experts will decide what is best for you, and you must receive it and like it. The notion that the future is something produced by a few and the majority only receive it passively is an affront to a free society.

maaarghk 11y ago
I'm pretty confused by your logic, I certainly don't think that it implies, for example, that the reader would be unable to go into education and go down a career path where they would become one of the few experts who are working in this field. It even links to papers and technical articles.
mohaine 11y ago
I'm assuming that is because this future WILL be created by experts. That isn't elitist, but if you want to help you will have to put in the time an effort to became an export.

legulere 11y ago

Producing enough food is basically a solved problem, distribution and hindering people to eat an everincreasing amount of meat is the problem

Blahah 11y ago
This is partly true, but is not helpful. The goal is for nobody to go hungry. By increasing crop yields in the most common staple crops, we have a clear technological engineering problem to solve and various ways to approach it, all achievable. This allows more food to be produced more cheaply in the areas that need it most. If we refuse to produce more food until the food that is already produced is distributed evenly, many people will die or go hungry because the socio-political problems are very complex. There is no engineering solution to them in sight. By all means let's try to solve problems of inequality. But let's also try to feed people as soon as possible by whatever means are available.
- marktangotango 11y ago
  Feeding the world isn't a tech problem, it's a public policy problem. Blows my mind how little people know about this.
  - Blahah 11y ago
    It is clearly both, which is what I said above. Synchronising the entire global economy is harder and less tractable than engineering photosynthesis, so we should be working on both (which is exactly what we are doing).
briantakita 11y ago
Monoculture, petrol, chemical agriculture is often produced in a centralized manner, which introduces inefficiencies (with environmental issues) in transport, fertilization, pest control, etc. The current paradigm also requires large amounts of capital to purchase machinery, mined fertilizer, poisonous pesticides, GMOs where seeds can't be saved, etc. This cycle of dependence has caused many small farms to be in financial crisis. Also, don't forget that large scale factory farming is subsidized by the government. Without these subsidizations, large scale factory farming is not viable. Factory meat production follows the same pattern of monoculture, with disgusting & unhealthy results. The alternative is to decentralize food production. Small, organic, polyculture farms reduce or eliminate the need to transport food over long distances, import fertilizer, use pesticides. Decentralized food production also enables the farmer to be independent of having to purchase expensive inputs from large multinational corporations. Small farms are more humane and, similar to startups, freer to innovate.

briantakita 11y ago

“Problems cannot be solved with the same mind set that created them.” ― Albert Einstein There are more natural ways to achieve the same results. Perennial Polycultures use natural flora & fauna in a closed loop ecosystem. They also have higher overall yields than monocultures. These solutions are available to us right now. In fact there's a growing movement of farmers who are utilizing & learning more about Perrenial Polycultures. Here is some literature: http://www.amazon.com/The-One-Straw-Revolution-Introduction-Classics/dp/1590173139 http://www.amazon.com/The-One-Straw-Revolution-Introduction-... http://www.edibleforestgardens.com/about_book http://www.edibleforestgardens.com/about_book http://www.afforestt.com/index.html http://www.afforestt.com/index.html Here are some farms that I'm familiar with (either I know the farmers or they are well known): http://www.newforestfarm.net/ http://www.newforestfarm.net/ http://www.polyfacefarms.com/ http://www.polyfacefarms.com/ http://www.fieldswithoutfences.org/ http://www.fieldswithoutfences.org/ http://www.thevitalfarm.com/ http://www.thevitalfarm.com/

pvaldes 11y ago

There are some problems with plants, and one of them is that plants are, often misunderstood, live beings that are strategist by nature. If you put an improved photosyntesis in rice, this could lead to more grain of course, but also could boost the production of leaves and roots and the result could be less or none grain in the same time. Or atract predators. Have you consider this possibilities?