Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent

Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent
Aerial view of the 2017 field trials where scientists studied how well their plants modified to shortcut photorespiration performed beside unmodified plants in real-world conditions. They found that plants engineered with a synthetic shortcut are about 40 percent more productive. Credit: James Baltz/College of Agricultural, Consumer and Environmental Sciences

Plants convert sunlight into energy through photosynthesis; however, most crops on the planet are plagued by a photosynthetic glitch, and to deal with it, evolved an energy-expensive process called photorespiration that drastically suppresses their yield potential. Researchers from the University of Illinois and U.S. Department of Agriculture Agricultural Research Service report in the journal Science that crops engineered with a photorespiratory shortcut are 40 percent more productive in real-world agronomic conditions.

"We could feed up to 200 million additional people with the calories lost to photorespiration in the Midwestern U.S. each year," said principal investigator Donald Ort, the Robert Emerson Professor of Plant Science and Crop Sciences at Illinois' Carl R. Woese Institute for Genomic Biology. "Reclaiming even a portion of these calories across the world would go a long way to meeting the 21st Century's rapidly expanding food demands—driven by population growth and more affluent high-calorie diets."

This landmark study is part of Realizing Increased Photosynthetic Efficiency (RIPE), an international research project that is engineering to photosynthesize more efficiently to sustainably increase worldwide food productivity with support from the Bill & Melinda Gates Foundation, the Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).

Photosynthesis uses the enzyme Rubisco—the planet's most abundant protein—and sunlight energy to turn and water into sugars that fuel plant growth and yield. Over millennia, Rubisco has become a victim of its own success, creating an oxygen-rich atmosphere. Unable to reliably distinguish between the two molecules, Rubisco grabs oxygen instead of carbon dioxide about 20 percent of the time, resulting in a plant-toxic compound that must be recycled through the process of photorespiration.

Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent
Four unmodified plants (left) grow beside four plants (right) engineered with alternate routes to bypass photorespiration -- an energy-expensive process that costs yield potential. The modified plants are able to reinvest their energy and resources to boost productivity by 40 percent. Credit: Claire Benjamin/RIPE Project

"Photorespiration is anti-photosynthesis," said lead author Paul South, a research molecular biologist with the Agricultural Research Service, who works on the RIPE project at Illinois. "It costs the plant precious energy and resources that it could have invested in photosynthesis to produce more growth and yield."

Photorespiration normally takes a complicated route through three compartments in the plant cell. Scientists engineered alternate pathways to reroute the process, drastically shortening the trip and saving enough resources to boost plant growth by 40 percent. This is the first time that an engineered photorespiration fix has been tested in real-world agronomic conditions.

"Much like the Panama Canal was a feat of engineering that increased the efficiency of trade, these photorespiratory shortcuts are a feat of plant engineering that prove a unique means to greatly increase the efficiency of photosynthesis," said RIPE Director Stephen Long, the Ikenberry Endowed University Chair of Crop Sciences and Plant Biology at Illinois.

Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent
Scientists Don Ort (left), Paul South (center) and Amanda Cavanagh (right) study how well their plants modified to bypass photorespiration perform beside non-modified plants in real-world conditions. They found that plants engineered with a synthetic shortcut are about 40 percent more productive. Credit: Claire Benjamin/RIPE Project

The team engineered three alternate routes to replace the circuitous native pathway. To optimize the new routes, they designed genetic constructs using different sets of promoters and genes, essentially creating a suite of unique roadmaps. They stress tested these roadmaps in 1,700 to winnow down the top performers.

Over two years of replicated field studies, they found that these engineered plants developed faster, grew taller, and produced about 40 percent more biomass, most of which was found in 50-percent-larger stems.

The team tested their hypotheses in tobacco: an ideal model plant for crop research because it is easier to modify and test than food crops, yet unlike alternative plant models, it develops a leaf canopy and can be tested in the field. Now, the team is translating these findings to boost the yield of soybean, cowpea, rice, potato, tomato, and eggplant.

Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent
The red car represents unmodified plants who use a circuitous and energy-expensive process called photorespiration that costs yield potential. The blue car represents plants engineered with an alternate route to shortcut photorespiration, enabling these plants to save fuel and reinvest their energy to boost productivity by as much as 40 percent. Credit: RIPE Project

"Rubisco has even more trouble picking out carbon dioxide from oxygen as it gets hotter, causing more photorespiration," said co-author Amanda Cavanagh, an Illinois postdoctoral researcher working on the RIPE project. "Our goal is to build better plants that can take the heat today and in the future, to help equip farmers with the technology they need to feed the world."

While it will likely take more than a decade for this technology to be translated into food crops and achieve regulatory approval, RIPE and its sponsors are committed to ensuring that smallholder farmers, particularly in Sub-Saharan Africa and Southeast Asia, will have royalty-free access to all of the project's breakthroughs.


Explore further

Scientists boost crop production by 47 percent by speeding up photorespiration

More information: P.F. South el al., "Synthetic glycolate metabolism pathways stimulate crop growth and productivity in the field," Science (2018). science.sciencemag.org/cgi/doi … 1126/science.aav8979
Journal information: Science

Citation: Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent (2019, January 3) retrieved 19 July 2019 from https://phys.org/news/2019-01-scientists-shortcut-photosynthetic-glitch-boost.html
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Jan 03, 2019
so stripping the plant's ability to turn carbon dioxide into oxygen we can gain greater yield, basically.

typical gates agenda. creat global warming at all costs. smh
where's the bill Nye follow up report?

Jan 03, 2019
They didn't do that. They made it EASIER for the plant to convert CO2 into carbs and oxygen. Not harder.

Jan 03, 2019
so stripping the plant's ability to turn carbon dioxide into oxygen we can gain greater yield, basically.

typical gates agenda. creat global warming at all costs. smh
where's the bill Nye follow up report?

Did you even read the article? Photorespiration is anti photosynthesis. Which is plants consuming oxygen instead of carbon dioxide,and is an undesirable trait that they dealt with,not the other way around. You daft little american redneck you

Jan 03, 2019
Red necks are simply an adaptation to sunlight involving pheomelanin production in the epidermis of exposed areas. Americans are people who live in the Americas. Thus, I suspect the original commenter's problem lies elsewhere, such as trying to view science through a political lens.

Jan 03, 2019
"so stripping the plant's ability to turn carbon dioxide into oxygen we can gain greater yield, basically."

You are a willful idiot.

Jan 03, 2019
Oh please Whacked! Please do mot confuse the American People with the russian trollbots like nematode. It's just here to agitprop for it's pimp putin.

The way you can tell it's a fake commentator? It's stupidity at failing to immediately grasp the economic advantages in controlling such technology & exporting more foodstuffs.

No proud Yankee would ever leave money like that lying on the table!

& yeah Whacked, your presumption that nematode is a braindead inbred redneck is probably closest to the reality.

What should concern you if your Aussie? Is that the nematode's trailerhome gets picked up by a tornado & dropped into Oz.

Jan 03, 2019
Worthy of Nobel Prize? That's Right. Panama Canal was a Great thing; Elon Musk should dig a tunnel around the planet underneath the oceans and Icy Polar Regions too. Only Governments can Invest in such an endeavor; Obviously, He should start with short expeditions first to test whether it is doable. Who knows how many generations will be needed to finalize it. Air is needed for respiration, but also is an impediment ! CO2 is Gold for Plants; O2 is Gold for Animals. As simple as that. 20% of the time, Plants STEAL our O2

Jan 03, 2019
Worthy of Nobel Prize? That's Right. Panama Canal was a Great thing; Elon Musk should dig a tunnel around the planet underneath the oceans and Icy Polar Regions too. Only Governments can Invest in such an endeavor; Obviously, He should start with short expeditions first to test whether it is doable. Who knows how many generations will be needed to finalize it. Air is needed for respiration, but also is an impediment ! CO2 is Gold for Plants; O2 is Gold for Animals. As simple as that. 20% of the time, Plants STEAL our O2

Air = Hurricanes, Tornadoes !

Jan 03, 2019
Red necks are simply an adaptation to sunlight involving pheomelanin production in the epidermis of exposed areas. Americans are people who live in the Americas. Thus, I suspect the original commenter's problem lies elsewhere, such as trying to view science through a political lens.

Best response I've seen in a while... :-)

Jan 03, 2019
How come Blue beats Red in the Animation ?
Blue Sky is Great. Blue Oceans are Great. Red Volcanoes are BAD !

Jan 03, 2019
But Elephants are Too noisy with sounds that are 112 decibels Loud; Donkeys' Braying (80 decibels) can be heard at least 1.75 miles (3 kilometers) away.

Jan 03, 2019
That is a hefty improvement! Precision engineering, lower risk GMO for the win again. (If people put down their political axes and act for the better of the planet. Also, ironic how the the first troll inverted what plants do.)

Jan 03, 2019
Quite an impressive accomplishment; well done. That being said, why not engineer Rubisco to selectively bind CO2, and eliminate the photorespiration problem entirely? I recognize that it is easier said than done, of course, but engineering three alternative pathways to shortcut, but not eliminate, photorespiration was no doubt a significant challenge too. It just strikes me as ironic that in the process of looking for a "shortcut", this team seemed to take the long way around.

Jan 03, 2019
I do have to admit that it was pretty savvy to work on boosting the yield of tobacco as the test crop, considering the current "climate" in America. Who needs to rely on research grants from an administration who can't wrap their minds around the complexities of an effing wall, when you can get your funding straight from Altria?

Jan 03, 2019
Tobacco is a well understood and genetically mapped out plant with easy growing conditions. It's been used to test various types of genetic modifications since 80s that I know of.

Finding a work around for the photorespiration issue is probably a whole lot easier than trying to create a whole new method to capture CO2 for the photosynthesis process as it would likely take a completely different molecule and working it into the new photosynthesis system. I really don't think they're ready for that. It's kind of like trying to mod a 60s Era VW Bug to have a big-block engine when all you really need to do is rebuild the carburetor.

Jan 03, 2019
This is great news, if true. I am just wondering if there is a catch. If this photosynthetic change is so great, why didn't the nature do it?

Jan 04, 2019
You have to ask, if 40% yield is better then why is this "glitch" so universal? Why doesn't evolution favor the more efficient route?

It seems to me that they discovered a way to induce a metabolic disorder that causes the plant-equivalent of morbid obesity.

Jan 04, 2019
@Eikka, evolution doesn't always optimize everything. For example, your knees are weak because they're backwards.

Jan 04, 2019
Increasing the ability to produce more oxygen is a good thing but I doubt that it will come close to the O2 producing rain forests that have been destroyed. A way to stop humans from breeding like flies might be a better 'discovery'. Also since these new crops are to be GMO's, I suspect that the improvemnt will not be passed on to there seeds so farmers won't have to buy them new every year from the Bayer monstrosity and companies like them. A modification that would make them less reliant on artificial fertilizers and chemical pesticides or weed killers is also out of the equation. Sustainable agriculture is the answer not Frankenstein plants.

Jan 04, 2019
@Eikka, evolution doesn't always optimize everything. For example, your knees are weak because they're backwards.

Da Snot, the "meat" loving, knob gobbler, brays again.
This jackass has STRONG knees, but they do go weak when his boyfriend is trying to hit his "sweet spot".

Jan 04, 2019
You have to ask, if 40% yield is better then why is this "glitch" so universal? Why doesn't evolution favor the more efficient route?


Excellent question. There are a few logical hypotheses, such as:
1. The 'fix' isn't actually helpful to the plant, e.g. it's "plant obesity" like you mention, or causes some other problems yet to be discovered.
2. The 'fix' wasn't accessible through normal evolution due to barriers, such as intervening steps that have low fitness.
3. Evolution would get the 'fix' eventually, but there hasn't been enough time.

3 seems highly unlikely. Both 1 and 2 are quite plausible. The researchers are surely hoping for 2, a genuinely beneficial fix.

However, even if the answer is 1, it's not necessarily a bad thing for an agricultural plant. For example, seedless grapes would be a horrible mutation for a grape plant, UNLESS people propagate it. Nevertheless your question would have to constantly be on the minds of the researchers.

Jan 04, 2019
... why not engineer Rubisco to selectively bind CO2, and eliminate the photorespiration problem entirely?.


People have tried that, but increasing selectivity can decrease catalytic speed:

"Most Form I Rubiscos (those found in land plants, green algae, and cyanobacteria) appear to exhibit a trade-off between catalytic turnover rate (speed) and substrate specificity." https://www.resea...vity.pdf

Jan 04, 2019

3. Evolution would get the 'fix' eventually, but there hasn't been enough time.

Evolution has already gotten the fix in many plants.

Jan 04, 2019
@Eikka, evolution doesn't always optimize everything. For example, your knees are weak because they're backwards.


If having a different kind of knee would carry a 40% advantage in locomotion without other drawbacks, most animals would have them.

An obvious reason comes to mind: knees are evolved to lock up into stilts, so you wouldn't have to use continuous muscle effort to remain standing. It enables passive dynamic walking, which consumes much less energy, so the advantage is actually the other way around.

Jan 04, 2019
"Evolution has already gotten the fix in many plants."

In C4 plants?

Jan 05, 2019
[Scientists engineer shortcut for photosynthetic glitch, boost crop growth by 40 percent


Carbon shortage. Fire up the coal plants.

Jan 05, 2019
You have to ask, if 40% yield is better then why is this "glitch" so universal? Why doesn't evolution favor the more efficient route?

Because evolution doesn't work that way. Evolution doesn't go for 'optimal'. It goes for 'good enough'.
It's like the joke with the bear. You don't have to be the fastest runner possible to surive. You just have to be faster than the next guy.
As soon as a plant is slightly better than the next plant all evolutionary pressure to get better stops for it.

Jan 05, 2019
A glitch? In gods creation? That's not possible is it?

Jan 05, 2019

As soon as a plant is slightly better than the next plant all evolutionary pressure to get better stops for it.

WOW!! REALLY??
That's how evolution works?
Well, it would certainly explain, why your brain did not evolve beyond a single neuron.

Jan 05, 2019
@Eikka, evolution doesn't always optimize everything. For example, your knees are weak because they're backwards.


If having a different kind of knee would carry a 40% advantage in locomotion without other drawbacks, most animals would have them.
They do. Maybe you haven't looked at a dog's hind legs recently. Or a horse's. Much better if you want to run fast. And not as weak.

Jan 05, 2019
Evolution doesn't go for 'optimal'. It goes for 'good enough'.
And that's how evolution works.

And diversity is the best guarantee of a supply of beneficial alleles.

Jan 06, 2019
Evolution doesn't go for 'optimal'. It goes for 'good enough'.

Best not to ask evolutionists these kind of intelligent questions. Because they have no idea what they are talking about. All conjecture and no science. And they keep making up fantastic stories as they go along.

Jan 06, 2019
Hey bart, why is there a glitch in gods creation? Is this because of original sin? Was Adam and the apple/pomegranate incident the cause of diabetes? How about earth's axial tilt and precession?

And if these glitches and maladies are punishment for giving in to gods temptation (he created that fruit tree in the first place didnt he, and filled it with irresistible fruit?) then why are we able to fix them without his help?

IOW does science, medicine, and engineering represent an affront to gods judgement against the human race? Ie additional sin?

Maybe he made them fixable because he felt guilty, like when he decided to punish David's census with the murder of 10k innocent followers, but then called it off. Maybe science is an indication that god feels guilty for messing up the entire universe just because the first man took a bite of fruit.

Jan 07, 2019
It seems to me that they discovered a way to induce a metabolic disorder that causes the plant-equivalent of morbid obesity' by Eikka

'Sustainable agriculture is the answer not Frankenstein plants' by Seedcollector

Exactly

Jan 07, 2019
You have to ask, if 40% yield is better then why is this "glitch" so universal? Why doesn't evolution favor the more efficient route?


Excellent question. There are a few logical hypotheses, such as:
1. The 'fix' isn't actually helpful to the plant, e.g. it's "plant obesity" like you mention, or causes some other problems yet to be discovered.

You've stumbled on a key point.
If people followed a caloric restricted diet we wouldn't need to make plants "obese" in order to feed more people.. "Obesity" is not just bad for people...

Jan 08, 2019
They do. Maybe you haven't looked at a dog's hind legs recently. Or a horse's. Much better if you want to run fast. And not as weak.


I don't understand. A dog's knees bend the same way as ours. Horses too, and they have locking knees that enable standing up much like ours. (they can sleep standing up) Maybe you're confusing the ankle for the knee, which is again the same as we have - only the foot is longer and these animals walk on their toes.

Jan 08, 2019
Maybe you forgot that knees aren't elbows. The knees are on the back legs in quadrupeds. In bipeds they're on the bottom.

Ummmmduh.

Jan 08, 2019
As for running, humans use the same tiptoe method for speed and agility, taking the impact on the achilles tendon, only, we can keep standing up without much strain while the dog has to lay down because it can't turn its legs into stilts. We're much more efficient walkers because of it too, because our knees lock up and swing us over like an inverted pendulum, while the dog has to spend constant muscle effort to keep its body up from the ground. Hence why humans are superior at distance.


Jan 08, 2019
Maybe you forgot that knees aren't elbows. The knees are on the back legs in quadrupeds. In bipeds they're on the bottom.

Ummmmduh.


Umm... actually, what you might think as the knee of a horse's front legs is its carpus, which is equivalent to the wrist in humans. These animals are digitigrade - they walk on their "toes" and "fingers".

Humans don't walk on front limbs, so the question of which way an animal's front legs turn is irrelevant. The hind legs of mammals are all alike - the difference is whether you walk on your heel or your toes.

Jan 08, 2019
https://en.wikipe...le_joint
The stifle joint (often simply stifle) is a complex joint in the hind limbs of quadruped mammals such as the sheep, horse or dog. It is the equivalent of the human knee


http://susangarre...ps-1.jpg

See which way it turns? Same way as ours. Because it's the same joint.

Jan 08, 2019
Are you serious?

I think you made my point: Plantigrade locomotion is a result of the evolution of the knee from the knees of primates, who lived in the trees. You might want to look at ostriches some time.

Jan 08, 2019
Are you serious?

I think you made my point: Plantigrade locomotion is a result of the evolution of the knee from the knees of primates, who lived in the trees. You might want to look at ostriches some time.

Da Snot, the "meat" loving, knob gobbler, brays again.
With his boyfriend pummelling the stupid out of his ass, you would think that he would be getting less stupid.
LMAO.

Jan 08, 2019
Are you serious?

I think you made my point: Plantigrade locomotion is a result of the evolution of the knee from the knees of primates, who lived in the trees. You might want to look at ostriches some time.


Still the same structure, and the knee isn't "backwards" in humans - it's exactly the same way as it is in dogs, horses and apes. It may look a little different and for a different purpose, but it's still the same basic anatomical feature with the same muscles connecting in broadly the same places, making it work the same way.

I think you made my point: Plantigrade locomotion is a result of the evolution of the knee...


Nah, you're just shifting the goalposts. The question was whether the human knee was in "backwards". It isn't.

What you're calling the knee is the ankle, and humans can walk on tiptoes, and do run on the toes, so you're simply making a bizarre claim by saying that human legs are weak because the knee is backwards.

Jan 08, 2019
You might want to look at ostriches some time.

http://3.bp.blogspot.com/-0EOvqBO2lRg/TbLbJrQMw1I/AAAAAAAABhc/fPCXmxNB0PM/s1600/o.gif

An ostrich's knee is still the same way as ours, and the part that you seem to think is the knee is again its ankle, and their foot is their toes.

If you're trying to make the point of, why don't human legs bend forwards at the middle, the answer is obvious: they don't need to. They bend forwards at the ankle, just like with most other animals, for the exact same purpose.

Our evolution prioritized walking over running, carrying capacity over speed, and the ability to stand up, so we got longer thighbones and shorter tibias - whereas animals that run fast have it the other way around.

As to why this is "weak", I don't see your point. The same issues from locking knees happen with horses and their locking ankles which get worn and broken the same way, because they serve the same function.

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