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Biotech Science

Scientists Aim To Improve Photosynthesis 156

Posted by Soulskill from the evolution-is-lazy dept.
vasanth writes "Two new initiatives at the University of Cambridge aim to address the growing demand on the Earth's resources for food and fuel by improving the process of photosynthesis. Four transatlantic research teams – two of which include academics from Cambridge's Department of Plant Sciences – will explore ways to overcome limitations in photosynthesis which could then lead to ways of significantly increasing the yield of important crops for food production or sustainable bioenergy. Despite the fact that photosynthesis is the basis of energy capture from the sun in plants, algae and other organisms, it has some fundamental limitations. There are trade-offs in nature which mean that photosynthesis is not as efficient as it could be – for many important crops such as wheat, barley, potatoes and sugar beet, the theoretical maximum is only 5%, depending on how it is measured. There is scope to improve it for processes useful to us, for example increasing the amount of food crop or energy biomass a plant can produce from the same amount of sunlight."
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Scientists Aim To Improve Photosynthesis More

Scientists Aim To Improve Photosynthesis

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  • A similar story was posted not too long ago..

  • New Pigments! (Score:3)

    by NFN_NLN ( 633283 ) on Monday April 11, 2011 @11:28PM (#35789478)

    They should work on a pigment that absorbs useful light in the yellow-green band of the spectrum. Some of the inefficiency of photosynthesis comes from the fact that it only absorbs visible light in two narrow bands of the spectrum.

    • I think people are gonna object to being sold "greens" which are entirely black. Aesthetics matter just a teensy bit when it comes to food.

      • depends how hungry you are

      • Re: (Score:2)

        by WetCat ( 558132 )

        Red cabbage (http://en.wikipedia.org/wiki/Red_cabbage) has almost black, dark violet leaves. It tastes good.

      • And yet, none of plants mentioned had their leaves eaten. Instead, it is seeds that are eaten. As such, the colors of the parts eaten should not change.

      • Re: (Score:2)

        by vlm ( 69642 )

        I think people are gonna object to being sold "greens" which are entirely black. Aesthetics matter just a teensy bit when it comes to food.

        Then it'll mostly go to starving people. Its not like its going to be thrown away. Hey starving person, here's a pitch black head of lettuce... oh you don't like the color? Gimme it back then, I'll give it to someone whom prefers not to die of starvation. bye bye starving person and have a nice day or whatever you have left?

        Meanwhile I contemplate my side dish last weekend of diced apples, caramelized diced onions, chopped red bell peppers and some seasoning. Tasted bettter than it sounds. Not much "g

      • People now sometimes pay a ridiculous premium for any leafy green or flower which even approaches black. I don't think this will be a problem.

    • A few weeks ago I was looking to see if anyone was trying what you say! It's a very interesting concept.

    • Re:New Pigments! (Score:5, Interesting)

      by Anonymous Coward on Tuesday April 12, 2011 @12:42AM (#35789906)

      Disclaimer: My group is collaborating with one of the guys from the FA.

      It is not so simple as you think. But I see the same type of misunderstanding in many people in the field (especially the kind that is good at getting grants and bad at doing science, there are many of them...).

      Leaves are pretty well designed (I mean that not in the intelligent way), and being green is one of them. The pigments that absorb the majority of the light (chlorophylls) have absorption peaks in the blue and red, and the absorption for green is indeed quite low. However, if you look at the total absorption spectrum of a whole leaf you will see the dip in the green is only 10-20% for most leaves. It is even less if you consider the whole canopy. Nevertheless our eyes pick up this small difference so that leaves look green.

      The problem with having black leaves (i.e. absorbing all light, some seeweeds do that) is that you get too much energy in the upper most layer of your leaf (a leaf is several hundred micrometers thick), giving you plenty of energy, but other things (enzyme capacity, CO2 levels, etc) become limiting. Thus, this absorbed energy is wasted, or even starts to damage things (lots of electrons flying around is not always a good thing).

      Thus, the green "window" allows part of the light to travel into deeper layers of the leaf, which is also often more porous, resulting in more scattering (longer pathlength, thus increasing chance of absorption) of the light. In this way, the green light drives much of the photosynthesis in the lower part of a leaf. Spreading out the light energy over several 100 micrometers makes the leaves much more efficient, but this would not work if the pigments absorbed green light equally well.

      That is not to say that nothing in the pigments can be optimized. Crops are often large stands of genetically identical organisms. We want to optimize the growth of the whole group. This is different from what might have been selected for by evolution (in a mixed canopy, a good survival strategy is to overshadow your competitors, i.e. become tall and allocate more pigments to the top). Big increases in grain yields were realized by breeding for shorter plants (little stem, mostly leaves). This would not work in nature because if one genotype starts to cheat (become bigger), the others will be starved of light. A similar gain might be possible by optimizing pigment allocation to allow a better distribution of the light (most plants still put too much in the top).

      • Very nice post—I had no idea that wavelength influenced depth of penetration. I had been under the impression that prior to the oxygen catastrophe, photosynthesizers used the other portions of the spectrum because of better atmospheric transmittance, and that green plants only flourished to exploit the new wavelengths that were being transmitted better. I hadn't considered that most of those photosynthesizers were probably the ancestors of e.g. red algae. Thanks for that insight.
      • While I think that what you are up is interesting (for starters, it will pick up more CO2), There is another choice, which is to increase the amount of soil that is devoted to a plant, by removing others. One that I see an issue with, is sugar beets. It would be quite a bit simpler to modify algae, or even Cyanobacteria to emit sucrose. With that approach, we could take Sugar beets our of production and devote the land to wheats, corn, etc.

        Regardless, good luck with your efforts. Most ppl do not realize i
        • Thats' why we don't use most of our farmland in the US. We've hit a wall: Too damn much food. Seriously man, cane sugar > beet/algae/HFCS sugar.
      • This is not intended as a flame, rather, it is offered as food for thought.

        I find it hard to believe that we could improve on a billion years of evolution of what is now the state of the art for converting sunlight to energy. I find it even harder to believe that we could not do that without making some sort of catastrophic mistake that wipes out the food supply by rendering it unsuitable for all other life. Sorry, I'm just a pessimist when it comes to genetic engineering and I'm very unhappy about the

        • Re: (Score:2)

          by vlm ( 69642 )

          My point is, humans are not even remotely smart enough to be messing with ... without making some really big mistakes first.

          What do you think of fire, or the wheel?

          • Depends on the context of your question. Can you be more specific?
            • You're being deliberately obtuse, but I'll explain anyway. Your argument is identical to people in the Middle Ages who refused to look through a telescope because it showed them things that God didn't want them to see. Those people also argued against eye-glasses -- after all, humans were created by God, and man couldn't (and shouldn't) improve upon God's creation.

              The only difference is that you're substituting God with evolution.

              There no reason to think that photosynthesis can't be improved, just like th
              • Your point is well taken, however, I've had a chance to observe the relative lack of caution that has been taken with GMOs. GMOs were released into the wild long before anyone could ascertain their dangers. GMOs were introduced into our food supply without any debate and very little knowledge on the part of the public.

                So while there are some who say there are benefits to GMOs, they seem rather reluctant to label them or tell us how we can avoid them. I suppose if the perverse incentives proffered by p

        • Let me add to this. Just supposing you *do* get all the energy out, possible... and you *do* transfer all that energy to useful carbohydrate production.

          And let's suppose that we *don't* see a huge increase in phophate and potassium depletion...

          Considering the track record of GE in America (Monsanto contaminating farmer's crops, and then charging huge amounts for the privilege), I do not believe that this will address hunger in the world. Rather, it will simply push the price of food up so high that it wil

          • >>I do not believe that this will address hunger in the world. Rather, it will simply push the price of food up so high that it will become impossible for the poor to eat. We'll have mass starvation like never before.

            How would increased agricultural production translate into higher prices? Historically speaking, increased yields have resulted in dramatic drops in food prices.

            Currently, we have the ethanol scam propping up corn prices at about twice what they should be. If you're concerned about high f

            • Well, increased production for export translates into higher prices for the locals. Further, the increased production results in the exporting company getting more money, and buying up the land from the natives who were getting along just fine on their farmettes.

              But who now can't get a decent wage, working that same increased production on that same land. So they starve.

              And no, they don't have a choice in the whole deal. That's how neoliberal capitalism works.

        • Re: (Score:2)

          by joss ( 1346 )

          > billion years of evolution of what is now the state of the art for converting sunlight to energy

          No, evolution's 'aim' was the propagation of its own dna. Our aims are different so its not unreasonable to suppose we can improve upon what evolution did when we're actively trying to achieve it while for evolution it was an incidental side effect.

          • I didn't say it was unreasonable. I just said it was dangerous in many ways. Often, we cannot comprehend the damage we can do with what seemed like a good idea at the time.
          • "No, evolution's 'aim' was the propagation of its own dna. Our aims are different"

            Excellent point. And to bring it back around....we are doing this so that we can propagate our own DNA. Evolution at work! The fungi-raising ants have surely went through this already; maybe it would be easier for us to evolve and meet the corn halfway.

        • I think the simplest solution is birth control. We can shape the world so it is simply food/energy/comfort for our ever increasing population, but will it be at the expense of all other bio-diversity. We westerners say we want the rain forests etc, but turn a blind eye when we want something from the rain forest be it minerals, diamonds, oil, ivory, spices, etc. Look at the latest go-daddy ceo elephant kill I think it was. It was justified because it was a rogue animal. Bad animal for destroying stuff on pe

      • Re: (Score:2)

        by v1 ( 525388 )

        You appear well-educated on the subject so I'll ask this question to you... I recall reading somewhere that in the past there were two competing strategies for photosynthesis, green and brown. (I assume brown was green & red) But green won the evolutionary war. Can you confirm this, and why was it? was it chance? can we stack the deck somehow to make brown work better now?

        • can we stack the deck somehow to make brown work better now?

          Nope, brown has been voted off the island. We all use fedex now.

      • I have no idea what I am talking about, but perhaps Green spots would allow for "columns" of penetration which given their 3d nature would really increase the absorptive "surface" area.

        I guess maybe the best option is to simply look in nature, at different configurations, and try and measure which is the most efficient and why. Assuming somewhat uniform internal photosynthesis mechanisms, one could then deduce other factors such as colour, shape, size, etc...

    • Re:New Pigments! (Score:5, Informative)

      by Anonymous Coward on Tuesday April 12, 2011 @01:03AM (#35790004)

      The photosystem is pretty good at capturing photons! It's after that initial step that the tough bits of chemistry come in.

      First up, whenever you capture energy, you will heat up, hence plants have to manage that, and they do that with radiating out the excess energy captured (it is a lot!). There are a bunch of publications on reducing chlorophyll quantity in algae, which led to an improvement in photosynthetic efficiency and a drop in the excess energy radiated out (I think it was in the red region).

      After that, the captured energy is used to split water, generating rather damaging radicals/ions (I forget which one) in the process - one changes your pH, the other causes redox stress. Either way, both are bad. The photo-system can't take a lot of that either, hence there are a ridiculous number of processes to effectively convert the split water back to water! (Refer Dynamics of Photosynthesis - Annual Review by Eberhard et al... Hah, luckily remember one paper from my thesis work!)

      It doesn't get much better by the time the Hydrogen ion travels across the membranes, creating the much wanted NADPH, and some ATPs in the process. Now, depending on the chemicals wanted by the cells, the ratio of NADPH/ATP need to be tweaked, losing some energy there too.

      And then come in the enzymes which start to use this simple energy to climb up the rather hard entropy ladder to create ordered polymers from the ridiculously simple water and carbon dioxide. Not the easiest of tasks in my opinion... and my un-calculated and un-verified bias is that the free energy change needed to accomplish this must be pretty high. Thermodynamics didn't like me very much... Nonetheless, the often abused number of 5% or 10% or 1% (yes, you can find all of these numbers in literature) photosynthetic efficiency means little as people always compare sunlight received to the calorific value of the biomass, completely missing out all the effort it took to build up that complexity against the rather real forces of disorder. Burning it is a complete waste!

      Which is why my money (when I will have money!) will be on chemically simpler fuels - higher efficiencies are possible. But unfortunately, none of our alternatives to biomass have the self-replicating chemistry awesomeness of Biology. Hence it's not very cheap to manufacture and maintain. Plants kind of grow... You don't have to do much. Except, of course, if you're a corn ethanol producer, where you're doing too much! ;)

      So basically, the problems are not at the pigments... The quantum yield of photon capture is near 100%. The complexity is after that. It's a mix of matching rates of various processes along the way, and losing energy working against entropy. And we're not even *close* to figuring out this system. Long shot.

      Sayash

  • Seems to me it'd be simpler to solve the world's food resource problem by figuring out how the plants do it... then cut out the middle man and do it ourselves. Screw farming... I'll be at the beach.

  • What could possibly go wrong? (Score:5, Funny)

    by eln ( 21727 ) on Monday April 11, 2011 @11:37PM (#35789546)
    This is a horrible, horrible idea. If you make photosynthesis more efficient, plants won't have to spend all their time generating food. A few hours a day, and they'll have all they need. Soon enough, plants will have more free time than they know what to do with. They'll wake up in the morning, spend a couple of hours making sugar, and spend the rest of the day sitting in coffee shops and arguing about the finer points of whatever passes for philosophy among the members of the plant kingdom.

    Eventually, various collectives will form based on commonalities of ideas and who is rooted near what coffee shop. Sure, most of these collectives will concern themselves primarily with taking drugs and producing regrettable artworks, but eventually some of them will start to ponder their lot in life at the constant mercy of mankind. This will lead to the writing of lengthy treatises on the Rights of Plants and how they are constantly being trod upon (often quite literally) by man. After that, it's only a matter of time before they rise up under the banner of the Glorious Plant Revolution and kill us all.

    Honestly, the last thing we can afford to do is make plants more efficient.

    • You know who else produced regrettable artwork? Hitler. The plants would produce bad artwork too. Ergo, they are equivalent to Hitler and must be stopped at all costs!

    • Re: (Score:2)

      by Nyder ( 754090 )

      This is a horrible, horrible idea. If you make photosynthesis more efficient, plants won't have to spend all their time generating food. A few hours a day, and they'll have all they need. Soon enough, plants will have more free time than they know what to do with. They'll wake up in the morning, spend a couple of hours making sugar, and spend the rest of the day sitting in coffee shops and arguing about the finer points of whatever passes for philosophy among the members of the plant kingdom.

      Eventually, various collectives will form based on commonalities of ideas and who is rooted near what coffee shop. Sure, most of these collectives will concern themselves primarily with taking drugs and producing regrettable artworks, but eventually some of them will start to ponder their lot in life at the constant mercy of mankind. This will lead to the writing of lengthy treatises on the Rights of Plants and how they are constantly being trod upon (often quite literally) by man. After that, it's only a matter of time before they rise up under the banner of the Glorious Plant Revolution and kill us all.

      Honestly, the last thing we can afford to do is make plants more efficient.

      But then we'll really be green, won't we?

    • Re: (Score:2)

      by vlm ( 69642 )

      This is a horrible, horrible idea. If you make photosynthesis more efficient, plants won't have to spend all their time generating food. A few hours a day, and they'll have all they need. Soon enough, plants will have more free time than they know what to do with. They'll wake up in the morning, spend a couple of hours making sugar, and spend the rest of the day sitting in coffee shops and arguing about the finer points of whatever passes for philosophy among the members of the plant kingdom.

      There is a (very tiny) gem of a real issue in your ... whatever. 50% more photosynthesis means 50% more sucrose (or whatever) means 50% more water needed to keep osmotic pressure constant. Or growth rate increases 50% meaning you need 50% more protein and cellulose synthesis required means 50% more fertilizer required. But that will screw up the ionic balance of the dirt so you need 50% more root growth and or 50% more inorganic filler (sand?) in the soil. Think of a factory, you make one machine at one

  • One of the things that always bugged me about zombie flicks was how the zombies seemed to be able to run perpetually without a steady source of energy ( ie: brains...or anything else ). Now it makes sense. The zombification process obviously employs a type of photosynthesis. This is further confirmed by the seemingly universal trope that zombies are most active during the day time.

    In either case, it has begun. This research will mutate with the common cold virus, resulting in a zombieland.

    • Re: (Score:2)

      by Co0Ps ( 1539395 )
      Ah. So that's the prologue to zombies vs. plants.

    • I always assumed zombies destroyed/consumed their own bodies as a source of energy, like the way a living person will consume their own muscle tissue if starved.

  • how about using the plants we have efficiently? (Score:4, Interesting)

    by nido ( 102070 ) <nido56@@@yahoo...com> on Monday April 11, 2011 @11:58PM (#35789676) Homepage

    Feeding grain to animals in concentrated animal feeding operations [cafothebook.org] is stupid. Farms should be run by farmers [cafothebook.org], NOT "absentee landlords" (like my dad & his two siblings, who inherited some ~200 acres from their parents. Grandma grew up on her farm, while Grandpa's parents owned their farm but never worked it). From the second link:

    And yet it is not impossible to imagine a far different food and farming system than the one we have today, beginning with a long-term commitment to pasture-based farming. Many have been advocating for some time for an ambitious transformation in U.S. agriculture: away from soil-eroding feed grains toward deep-rooted perennial pastures; converting large-areas of the High Plains back to grass and grazing operations; diversifying the corn and soybean dominated Midwest. In fact, thousands of family farmers are managing appropriately-scaled, grass-fed meat, dairy and egg farms without raising animals in vile and sordid conditions. A smart pasture operation (SPO)—to pick up on a new phrase—is one of the easiest entry points for beginning farmers in current U.S. agriculture. Start-up costs are relatively modest and markets for healthfully raised animal products are underserved and growing rapidly. These pasture-based rotational grazing systems can be extremely resource efficient, and often have the advantage of not needing the energy- and capital-intensive inputs such as heating, ventilation, and cooling systems, housing construction, imported industrial feeds, and mechanized manure management systems. They rely on sound animal husbandry techniques and integrate farm animals into a healthy landscape, using manure as a source of soil fertility. But this will require whole new generations of farmers willing to join the ranks of this noble profession, and legions of consumers and an financial and production infrastructure to support them.

    Many of humanity's health problems stem from the inappropriate use of grain crops. Grain-finished cattle have a fraction of the beta carotene and vitamin A as grass-finished beef.

    Feeding cattle directly on land currently used to grow soybeans & corn would be a lot more productive. But I don't think all the "farmers" (who really just hire tenants to plant crops) would approve.

    • Re:how about using the plants we have efficiently? (Score:4, Insightful)

      by SuricouRaven ( 1897204 ) on Tuesday April 12, 2011 @01:27AM (#35790118)
      Sorry, but there is no way that pasture systems can be as efficient as ithe modern intensive farming system. That's exactly why we use the intensive system - it can produce so much more food from a given area, and for such a low cost, that it's almost impossible for anything else to compete in the market. The only possible way is to target the premium market of customers who will pay extra, such as by labeling the food as organic.
      • You're right. This isn't about quantity, it's about sustainable quality.

      • Re: (Score:3, Interesting)

        by dkleinsc ( 563838 )

        Sorry, but there is no way that pasture systems can be as efficient as the modern intensive farming system.

        Sure it can, once you factor in all the costs, rather than the costs that the farmer pays directly. The kinds of costs I'm thinking of here:
        - Environmental damage caused by fertilizer runoff
        - The wars to secure the oil to create the chemical fertilizers that the farmers depend on
        - The depletion of the arable land, so that in a couple more generations the land that's currently used for growing feed corn will be able to grow nothing at all, ending up with another Dust Bowl
        - The CO2 emissions from the more int

        • Exactly! If federal subsidies for beef and dairy were removed consumers would actually face the true cost of raising cattle. In fact if subsidies matched more closely with the dietary needs of humans [yearofplenty.org], we might see a real revolution in public health in the US.
        • This is an economic matter. Externalised costs don't count, because someone else pays them.

      • Using up millions of years worth of stored energy and water in a few decades isn't what I'd call efficient. What happens when you've used up the oil and drained the aquifers?

        I'm not sure it's even that land efficient, that central-pivot irrigation seems to waste nearly a quarter of the land straight out.

      • It is efficient only because these intensive factory farms don't pay all the costs. They pass it on to the government, and other people. The factory farms do not have the inherent right to let their fertilizer run off and create algae blooms in the Gulf of Mexico. They do not have the right to let their noxious smelly wastes to waft across to their neighbors. They do not have some inherent right to ethanol subsidies, floor prices and special tax treatment in tax policies. When the factory farms pay full cos

  • Just what we need: Make hydroponic pot production even more efficient!

  • Look I'm very VERY much for kicking our fossil fuel addiction that causes global warming and is directly funding terrorism (republican appointed defense secretary Gates said most financial support for Taliban/Al Queda comes from gulf states not drug trafficking) but using crops for biofuels is not the way to go. Aside from the fact that some fuels (ethanol from corn) may require MORE energy to produce than is harvested, there are serious ethical issues when you have American S.U.V. drivers competing direct

  • We already have the technology necessary to prevent world hunger, it's called birth control. Are there any charities I can fund that aim to distribute birth control to poor countries? Because I would give money to that cause

    • Don't call it birth control; it's better called 'family planning'.

      A family is less poor not only if wisely chooses its number of children, but also the moment in time when they have it.

      In countries with high birth rates (children per woman) couples get their first child so early that usually they don't finish school, before getting any working experience that would grant them a safe monthly income, nor any time at those job positions to save some money while they could have.

      That's why I prefer the term Fami

      • Convince me that a college degree means greater financial wealth. Typically, I see all the profits sucked up by those in power, from the boss straight up to the president of the US.

        The problem isn't birth control. The problem is arrogance and greed. And although I disagree with Ayn Rand on many things, I do agree with her that that arrogance and greed will destroy the production chain, and initiate great destruction of wealth. In fact, it is already happening.

        In fact, it is happening at the hands of ove

    • We already have the technology necessary to prevent world hunger, it's called birth control.

      We don't even need technology to prevent world hunger, all we need are free and open democratic systems everywhere. Once you take out the dictators who hoard food and resources for themselves, world hunger becomes a past issue.

    • Stop illegal aliens and slow immigrants from going to nations where they already have a low birthrate. That will put pressure on nations who have not learned to control their own birthrates.
      Then fund protestants to convert roman catholics,mormons and muslims. Once you do that, then you will get ppl to use birth control and look beyond their church.
      Finally, figure out how to slow down Africa. [cia.gov]

      Good luck with that.

    • Americans for UNFPA [americansforunfpa.org]

    • Why do you object to hunger? It's a sensation that tells you it's time to eat, thus preventing starvation.

      Perhaps when you say "hunger" you mean starvation or severe malnutrition, in which case you should stop abusing the language, like everyone else who thinks he should run the world.

  • I have nothing against GM crops to some degree, but I have to wonder if this is a great idea.

    Every facet of a species' evolution is toward making it more successful in its environment. Clearly, these species have settled on a 5% efficiency as 'good enough' - not (Darwinistically) willing to trade-off higher efficiencies to lose some other feature.

    Are there other grasses that run at higher efficiencies? (Is sugar cane a grass?)

    Anyone know what the photosynthesis efficiencies are for the ORIGINAL versions of

    • Even if you can double output; the population growth even without the gains in food production is going to be higher than the rate of increased production. This means only a small period of time will exist where production gains actually help everybody before the population growth rate overcomes it and surpasses it.

      Overpopulation is the problem people do not want to address. All such talk about distribution is shallow because it doesn't matter if you evenly distribute all the food in a Marxist fashion rega

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