Category Archives: future challenge

More Forest Numbers and Tree-Planting Drones

Here’s a new idea under the sun… tree-planting drones.


Take a minute and think about all of the forest products you use in a day. I’m sitting on one right now as is my laptop. Anyone who’s bought school supplies in the last weeks has also consumed a fair amount. As an avid list-maker, I use my fair share of small pieces of paper for reminders and tasks to be done. Of course, let’s not forget the oxygen. The U.S. Forest Service estimates that forest products account for 4.5% of the total U.S. manufacturing gross domestic product at $190 billion in products annually and employing >900,000 people. There’s little room for doubt, forests are valuable both as they stand and as they fall.

I’ve mentioned before that numbers are important. In this context, numbers about forests can be extremely valuable. New research in Nature this week gives a new estimate of our global tree density. The good news… The earth has nearly an order of magnitude more trees than previously estimated by satellite imagery. The research team puts the total number of trees on the planet at 3.04 trillion. That’s more than 400 trees per person. To you, these numbers are likely just interesting statistics to impress your friends, but to scientists, conservationists and the forestry industry the new estimates of tree density are important for guiding management policies.

The new estimate is based on more than 400,000 ‘ground-sourced measurements of tree density from every continent except Antarctica.’ Translation: A lot of man-hours were spent by humans in a forest collecting tree density data. Of course, the team wasn’t able to count each and every tree, but this is more accurate data than estimating tree numbers from space. Check out the video below for a great data visualization of the world’s forests based on this new research.

If you were paying attention, forest numbers are not static. For various reasons around the globe forests are declining. Current estimates give a net loss of 10 billion trees a year. Some of this loss is due to forest fires, but for decades the forestry industry has become increasingly mechanized to efficiently harvest trees for all of those useful forest products. On the other side of the equation, replanting new trees has not experienced the same industrialization and relies heavily on meticulous man hours and dirty hands. The company BioCarbon Engineering seeks to change this and offers a new scalable model for planting trees using drones. Yes, drones for a noble purpose. The drones are engineered to shoot bullets wrapped in a biodegradable casing and containing soil with pre-germinated seeds into the ground. This could be used for replanting after forest fires or in other areas where forests need help with recovery.

From BioCarbon Engineering

From BioCarbon Engineering

They estimate that they can scale up to 1 billion trees per year. It greatly decreases the amount of human hours involved compared to hand-planting. It’s also more efficient relative to mass seeding because the seeds are pre-germinated, which will eliminate the loss due to bad seeds. The numbers are still not yet in the trees’ favor, but closing the gap with deforestation is a step in the right direction and the Lorax would be proud.


*Of course, BioCarbon Engineering could always enter into a relationship with that BIOS Urn company that uses your cremated ashes as the germination medium for tree seeds. Then you and your loved ones could have your ashes with tree seedlings shot almost anywhere to make a stand of trees somewhere in the wilderness rather than just one tree at a time with a single urn. But as I’ve mentioned before, that’s not exactly how photosynthesis and the carbon cycle works.

//The blog has been dark for a record length of time. Only for lack of time and not material. Regularly scheduled posts coming soon.

References and Links:

For more on the tree-counting research, check out this post over at The Quiet Branches blog.

Cyanothece 51142 by Michelle Liberton, Pakrasi lab

The Dangerous Double Life of a Distinctive Diazotroph

For many people around the world, tonight is one of the most anticipated nights of the year. In that spirit, here’s some new science, not under the sun, but under the moonlight and starlight. New research from Wegener, Nagarajan and Pakrasi* describe something new about the Photosystem II D1 protein, an unexpected source that photosynthesis researchers had long written off as conquered or fully explained.

Why would we care about photosynthesis at night anyway? It all comes down to the distinctive lifestyle of the cyanobacterium Cyanothece, which belongs to an interesting class called unicellular diazotrophs (word of the day). Like all cyanobacteria, they perform oxygenic photosynthesis but they have the bonus biochemical ability of nitrogen-fixation.

Nitrogen-fixers are capable of pulling nitrogen gas (N2) out of the air and turning it into ammonia which the cells can use as a nitrogen source for important molecules like protein and DNA. Other microbes can perform nitrogen-fixation, and you may remember them as the root nodule symbionts of legumes. If you’re not a nitrogen-fixer, you have to rely on ammonia or other nitrate compounds present in the soil, sea or your diet (depending on what kind of organism you are) to make the required nitrogenous biomolecules. Since the Earth’s atmosphere is 78% N2, you don’t have to be great at math to figure out that acquiring the ability to tap into the atmospheric nitrogen source advances your species in the game of life a considerable number of squares.

What does this have to do with photosynthesis? Why don’t more plants and cyanobacteria get in on this nitrogen-fixation biochemistry? There’s a critical fatal flaw in the photosynthesis/nitrogen-fixation biochemical tango. Nitrogenase, the enzyme responsible for the nitrogen-fixation reaction is hopelessly and irreversibly killed by oxygen. Oxygen destroys the protein enzyme that’s already been made and tells the genome not to even bother wasting energy trying to make it new. If you’ve been paying attention to the blog, oxygenic photosynthesizers like cyanobacteria and plants make oxygen via their PSII enzyme every time light shines on them. So for nonphotosynthetic soil bacteria and other microbes, it’s not a big deal to avoid oxygen and go anaerobic to fix nitrogen. Cyanobacteria, however, must lead dangerous double lives to combine these two opposing biochemical processes.

Anabeana spherica via Wikimedia Commons The more round cell in the center of the string is the nitrogen-fixing heterocyst.

Some diazotrophic cyanobacteria solve this problem by separating these two processes in space. Species like Anabeana can go through a special type of development where the cells divide themselves, but incompletely to form a connected network like beads on a string. Every tenth cell (heterocyst) gets an extra layer of cell wall, destroys its photosynthetic machinery, and commits itself to a life of nitrogen-fixation. These cells share their fixed nitrogen compounds with their neighbors, which in turn share their fixed-carbon from photosynthesis. This is a fascinating process still hasn’t given up all of its secrets and remains an active area of research.

Cyanothece 51142 by Michelle Liberton, Pakrasi lab

Cyanothece 51142 by Michelle Liberton, Pakrasi lab

Cyanothece, on the other hand, is a more ruggedly individualistic species that manages to perform both oxygenic photosynthesis and nitrogen-fixation within a single cell. It accomplishes this through a carefully controlled circadian rhythm. During the day, oxygenic photosynthesis occurs. During the night, nitrogen-fixation occurs. It sounds so simple, yet this elegance is far from easy. This is a true circadian process, in that, while some cues are definitely derived from light signals, the cells also have a strong internal clock that keeps the time of day and controls what biochemical machinery is active. Thus, near the hour of dawn and dusk, the cells are actively preparing for the metabolism to come. Also, if you were to train a culture of these cells under a certain day/night cycle for several days then switch them to continuous light, they would still maintain their circadian biochemical cycle for several days after the switch.

One issue that has puzzled researchers for some time is that the photosynthetic machinery, like PSII, is actively shut down at night. It’s not just that it’s dark, so there won’t be any photosynthetic oxygen production. Apparently, that’s not good enough. The cells actively shut it down. When researchers take culture samples of these cells during their dark period and shine light on them to check photosynthetic capability, there is no signal. Sure, there’s probably little chance any significant photosynthesis is occurring at night, but Cyanothece isn’t taking any chances. For these cells, no moonlight, floodlights from passing ships, comets, or even the blessed Eastern Star is going to interfere with their nocturnal nitrogen fixation.

Shutting down photosynthesis is no small feat. Again, if you’ve been paying attention to the blog, you will note that I’ve ranted on numerous occasions about how complex PSII is and how difficult it is to assemble  and reassemble from its individual parts. As far as energetics are concerned, it would be a losing battle for Cyanothece to completely disassemble its PSII at dusk only to resynthesize it again the next morning. I don’t care how hard-up it is for a nitrogen source. As it turns out, Cyanothece and other unicellular diazotrophic cyanobacteria solve this problem in a more graceful way, for which Wegener et al have provided new experimental evidence.

Cyanothece, like all other oxygenic photosynthesizers, contains multiple copies of the psbA gene encoding the D1 protein, which is a core subunit of PSII and critical for function. Since the advent of the genomic era, the genomes of numerous photosynthetic organisms have been sequenced revealing these multiple psbA genes, most of which have little or no protein sequence differences. These subtle changes have been linked to cells’ ability to fine-tune photosynthesis under certain conditions. However, Cyanothece and its cousins have a psbA gene copy that is particularly different- psbA4. If one were to take all of the site-directed mutants that photosynthesis researchers made to sort out PSII function over the last few decades since molecular biology techniques were available and threw them altogether into a single mutant gene, you would get psbA4. If PSII contained the D1 protein encoded by psbA4, there would be no C-terminal processing and no active site for water-splitting and oxygen production.

Why would any self-respecting photosynthetic organism retain such an utterly non-functional PSII subunit? The answer is because it does serve a critical function in the daily cycle of Cyanothece, just not during the day. The D1 protein encoded by the psbA4 gene, called a sentinel D1 protein (sD1), is made only for the night, when it does the only thing it still can do- fit right in the center of the PSII complex and prevent PSII function of any kind. There’s no chance of any oxygen production while sentinel D1 is on duty, but the cells can maintain most of the other PSII components in a stable complex (meaning they don’t have to be degraded and made fresh every morning). Then, Cyanothece can turn photosynthesis back on in the morning by replacing a single protein in its PSII complexes. The report by Wegener et al gives the first biochemical characterization of PSII complexes containing a sentinel D1 protein, providing evidence that this strategy works for controlling PSII oxygen production.


Performing oxygenic photosynthesis and nitrogen-fixation within the same cell is biochemically problematic, but the sentinel D1 protein appears to be the secret weapon for this dangerous double life. Through this strategy oxygenic photosynthesis and nitrogen fixation are “Always together, eternally apart.”** Many questions remain regarding the regulation of the transition from functional D1 to sentinel D1 at dusk and the reverse replacement at dawn. There are still outstanding questions regarding the D1 turnover event for any PSII in any photosynthetic organism, so it’s not at all clear what parts of this process Cyanothece uses or whether new factors are involved. Obviously, there must also be some sophisticated regulation to prevent the synthesis of sentinel D1 during the day.

While this work focuses on an organism you’ve never heard of, it has some interesting biotech implications for the future. As I mentioned, being able to both fix CO2 through photosynthesis and N2 through nitrogenase puts you at a significant metabolic advantage. And no, I don’t mean you. Remember, we’ve been through this- people are not photosynthetic. It would be great if one day we could engineer certain crop plants to combine these traits. Legumes already have this trick covered through symbiosis, but many other staple crops require tons of nitrogen fertilizer. If researchers could unlock the secrets of Cyanothece’s double life and translate it to plants, then it may be possible to engineer versions of crop plants that don’t require so much nitrogen fertilizer. Thus, one night in the future, engineered crop plants may be fixing nitrogen thanks to the addition of a variant gene they already had.


*I know I’ve posted frequently about Pakrasi lab (my thesis lab) research, but this topic was just developing as I was leaving the lab and it’s too cool to pass up.

**Bonus points to you if you get the movie reference.

References and Links:

Dangerous Photosynthesizers

Because photosynthetic organisms are the energetic foundation of our biosphere, we always tend to think of them as allies, organisms with a positive connotation. Their trademark color green is universally linked with goodness, growth, and life. However, there are some bad apples in the bunch that just seem to have it out for us heterotrophs. Well, maybe not apples (though I’m sure there are some poisonous apples out there somewhere*), but nature is filled with examples of poisonous plants. Many toxins and pharmaceuticals have botanical origins.

The focus of today’s blog post sinks even lower- algae, pond scum, cyanobacteria. Most of these aquatic photosynthesizers quietly convert sunlight to biochemical energy without any ill effects to anyone. I’ve written previously, that under the right conditions (warm and nutrient-rich waters) these otherwise inconspicuous organisms bloom in great numbers and overwhelm their environments. Like all life on earth, algae are programmed to capitalize on favorable conditions for reproduction. The ultimate crashes of these blooms can result in aquatic dead zones, areas with dissolved oxygen levels too low to support life.**

Algal bloom in Lake Erie 2011 from the NASA Earth Observatory Credit: Jesse Allen and Robert Simmon via Wikimedia

However, in some cases, the effects of these algal ‘blooms’ go beyond sheer numbers. Some algae produce toxins which cause serious health problems for those of us heterotrophs sharing their environment. The individual constituents of these ‘harmful algal blooms’ (HABs) measure in at ~1-2 µm, but they can wreak all kinds of havoc on the scale of large cities. HABs can stop your summer fun by forcing beaches to close or eliminating certain shellfish from your diet, but this summer the problems went beyond recreation to something much more fundamental- potable water.

Clean, safe drinking water is a fundamental service of human civilization. In our modern society, just turn on the tap, cook, clean, bathe, drink. It has been such a staple of American cities that it is taken for granted. That is, until it’s no longer available. That was the exact situation in Toledo earlier this month. A large American city, in the year 2014, was without safe drinking water for a whole weekend. Approximately, 500,000 citizens were affected. All because of toxic algae.

Microcystin-LR chemical structure Credit: cacycle via Wikimedia

In this case, the culprit was a bloom of cyanobacteria which produce the toxin microcystin. This molecule is harmful to the health of humans, pets and wildlife by acting as a liver toxin. It also has neurotoxic effects. The toxicity of microcystins has been extensively characterized and long-known to be associated with certain cyanobacterial species. Because of the potential adverse effects of microcystin-producing cyanobacteria on modern water supplies, treatment facilities routinely check the levels of this toxin. Only one part per billion of this molecule is considered acceptable. When a microcystin-producing algal bloom occurs near the intake of a municipal water supply (as it did for Toledo this month) the facilities can quickly be overwhelmed causing the water supply to exceed acceptable microcystin levels. The situation is compounded by the fact that microcystins are resistant to boiling. While boiling water may destroy other toxins or contaminating bacteria, it only concentrates microcystins. In order to bring the toxin levels down, the problem must be addressed at the water treatment facility (using methods like activated carbon, ozone treatment and membrane filtration). By adjusting the normal procedures to account for increased microcystins, the water supply can be treated to once again safe levels. All of this is accompanied by exhaustive analysis of microcystin levels and vigilant monitoring after the incident.

Scientists and government agencies are always working to monitor our water systems for HABs. Check out some of the links below for descriptions of continuous efforts to monitor our environment for HABs. How do we get to the point of 500,000 people without water for a weekend with everyone watching out for it? I mean, we’re watching it from space! Even with all of these sophisticated tools and models, nature can be surprisingly swift. Check out these images and reports from the NOAA Great Lakes Environmental Research Lab on Aug 1, 2014 and Aug 4, 2014 showing false-colored images tracking the algal growth.

Simultaneously in the news cycle with the Toledo water crisis, two Ebola patients were being treated in premier isolation facilities on American soil. The nation’s attention was rapt with the details of their treatment and speculation was rampant as to the possibility of an outbreak in America (an infinitesimally small probability not worth talking seriously about among scientists and epidemiological experts, but a great ratings-driver). Worldwide, the Ebola death-toll numbers in the thousands, not just from this year, but ever. Based on pure body count, there are many deadlier infectious diseases, which we as the public dismiss more easily. Beyond those numbers, the lack of clean water for drinking, food preparation and sanitation results in the deaths of ~3 million people every year across the globe. A safe and reliable water supply, as a basic right, continues to elude human civilization.

Water, water everywhere, but not a drop to drink… Credit: de:Benutzer:Alex Anlicker

HABs are only a part of the world’s water problem. However, the disruption of Toledo’s water supply should have been an event that caught our attention and held it for a while longer. It may be easy to turn on the tap, but getting the clean water to that point takes a significant amount of effort with infrastructure maintenance, monitoring and treatment. All of these things are largely invisible to us in modern society. Unfortunately, all of these things are affected by other societal choices like economics, aesthetics, environmental regulations, and the practices of our agricultural systems and other industries. As a society, we should start having the longer, difficult conversations necessary to attack this complicated problem rather than the transient chats that occur when we are in crisis mode. Find out about your community’s water situation and the issues related to your supply. Talk to your community leaders today to ensure that safe water is part of your future.




*Hey, it’s hard to transition away from the summer’s Disney theme completely in a single post. However, I’m not just talking about the evil queen’s poisoned apple from the fairy tale. Apples have a huge amount of genetic diversity and I’m sure there are some varieties out there that are poisonous or so foul-tasting that you would think they are. After all, apples concentrate toxic substances in their seeds.

**In case you’re wondering, this year’s Gulf of Mexico hypoxic zone measured ~5500 square miles. That’s not breaking any records for size, but still about as large as the state of Connecticut. Read more about it here.


References and Links:

Plant Cold Tolerance

FrozenKicking off the scientific section of the Frozen series

Some plants can endure the cold,

Even freezing temps surviving

Gene transcription levels change ten-fold

But the important thing’s the timing.

CBFs start the response pathway,

Activating others to join the fray,

This works when there’s not a sudden freeze one day

It’s bad enough to lose a limb,

But plants must protect their meristems!


For those readers who are not compliant with our rodent overlord and have not seen the movie Frozen, here is a link to the Youtube clip with corresponding song.


Ice in biological systems is just as bad for plants as it was for poor Anna in Frozen. The sharp edges of ice crystals tend to rip biological membranes to shreds in ways they can no longer function or be repaired. In freezing temperatures, crucial biomolecules slowly lose mobility and grind to a halt. Both of these consequences violate central tenets of living systems. Cells need intact membranes to maintain the integrity of the ion gradients responsible for fueling bioenergetics, and all biochemical reactions depend on small motions in all molecules. Thus, all living things want to keep their cytoplasm from turning into snowflakes. So, how do plants deal with freezing temperatures? It’s not like they can just go inside their castles next to a warm fire. And for the record, acts of true love aren’t very helpful either. Today’s post explores how plants adapt to falling temperatures.

Temperature is an important factor governing the molecular details of plants’ lives. The activities of the enzymes that carry out routine metabolism are affected by the ambient temperature. The fluidity of plants’ numerous important membrane systems is also influenced by temperature. Consequently, plants must make significant internal adjustments to adapt to colder temperatures. Even though the leaves of your cold-hardy plants may not look any different in summer compared to winter, there are many molecular-level changes with respect to the types of proteins and membrane lipids that the cells contain. These changes require an energy commitment that makes it wasteful or impractical for plants to always have cold-tolerance turned on, so they have an elaborate system for inducing cold-tolerance.

Very few plant species would be able to survive Elsa’s magical wrath, which turned a normal summer day into deep winter. For the most optimal cold-survival, plants need exposure to lengths of cold-but-not-freezing temperatures to trigger internal pathways to get ready for freezing temperatures. This generally works well for plants on Earth* since the cooling temperatures of autumn precede the first snowfalls of winter. During this time, plants are acclimating at the molecular level for the onslaught of months of freezing temperatures. It shouldn’t be that surprising that cold-acclimation is linked to plants’ circadian clock and timekeeping mechanisms for day-length since these are also tightly connected with seasonal temperature changes.

winteriscomingPlant scientists have been working out the details of just what plant cells are doing during this acclimation time. One of the first things triggered by colder temperatures is the gene expression of the CBFs (C-repeat Binding Factors). These CBF regulatory proteins then activate other genes responsible for the grunt work of protecting cells from freezing temperatures. This layered response gives the plants more ways to regulate the biochemical changes as well as simplifies the initial activation of the pathway. The exact functions of the structural proteins which confer freezing-tolerance are still under investigation, but they have roles like stabilizing membranes under freezing temperatures or producing cryoprotectant molecules like sugars. Plants also change expression of genes controlling development so that growth is controlled during dangerously cold seasons. Teasing out the underlying mechanisms plants use to protect themselves from freezing temperatures is an active area of research in plant science.

Frozen plants by rockmylife via DeviantArt

Frozen plants by rockmylife via DeviantArt

Researchers are also interested in how cold-acclimation systems differ between plant species in order to gain insights as to why plant species have such differences in cold-tolerance (say, citrus vs. pine). Is it because the less cold-tolerant species don’t have some of the structural proteins necessary to protect cells during freezing temperatures? Or is it because the cold-sensitive species lack or have less responsive regulatory proteins for acclimation? Can the genes responsible for cold-acclimation be transferred to cold-sensitive plants to confer better freezing tolerance? Plant scientists are diligently working to find answers for these questions.

Hey, I’m sure there is some agribusiness that would love to open the market for citrus crops up to farmers in Minnesota,**but I think more modest adjustments in hardiness for certain agriculturally important crops are what they are aiming for. Even so, you may be wondering at this point, “Haven’t scientists been wailing for years about how the climate is getting warmer not colder? Why bother with cold-tolerance now? Can’t we just wait it out?” I’d say, “Sure, when there is beachfront property in Arkansas, go ahead and grow grapefruit there.” However, the story is a little more complicated than that, and it’s also important to mention that freezing-tolerance isn’t all about the thermometer. A big part of dealing with freezing temperatures means coping with less available liquid water. In studying freezing-tolerance, scientists have also uncovered connections with drought tolerance. That’s right, the same systems that kick in to handle frost intersect and merge with those conferring drought-tolerance. Thus, the more we know about freezing tolerance, the more we learn about drought tolerance. I think we can all agree that finding more ways to increase drought tolerance in plants is useful in places other than fairytales.



* I can only hypothesize that the flora of fairytale worlds has a much quicker cold-tolerance induction response or that there is other magic to mitigate sudden frost damage.

**Hey, maybe there’s an idea for finally getting rid of that awful citrus greening that’s decimating Florida’s citrus groves. I have a feeling the insect vector that carries the disease will have a difficult time surviving winters in the northern Midwest.

References and Links:


The Countdown Starts…



Earth below us, greening, glowing, cycling carbon, photosynthesis!

Red fluorescence tells the story, satellites can measure, measure it!

Wait, those aren’t the lyrics to Major Tom Coming Home. Not quite, but more appropriate for the upcoming OCO-2 NASA mission scheduled to launch in less than 24 hours! That stands for Orbiting Carbon Observatory-2, a satellite equipped with instruments to measure carbon dioxide in the Earth’s atmosphere. What does photosynthesis have to do with it? A lot. No matter how the carbon dioxide finds its way into the atmosphere- vehicle emissions, thawing tundra, the panting of my dogs in the Louisiana summer heat- photosynthetic organisms are its ticket out of the atmosphere and back into the solid state. The OCO-2 satellite will be collecting spectral data for direct measurements of atmospheric carbon dioxide as well as sun-induced fluorescence to monitor photosynthesis on a global scale.


Watching in a trance, the crew is certain, Nothing left to chance, all is working…

Now that you know what the OCO stands for, you might be wondering about the 2. Of course there was a ‘1’. Starting with 2 would just drive people like the scientists and engineers at NASA crazy. The OCO-1 launched in 2009 with a similar mission to collect carbon dioxide concentration data, but it failed to launch properly and crashed into the ocean before making it anywhere close to its orbit. Sigh. After I’m sure a lot of this happened, the scientists and engineers got back to work to make the replacement mission even better. You can bet that everything has been quadruple checked this time.*


Starting to collect requested data, What will it effect when all is done?

Remember when I told you how nifty it was that satellites were measuring photosynthesis from space while I was making the same measurements in the lab? Well, it’s not just a scientific novelty being measured because it can be. Chlorophyll fluorescence on a global scale provides critical information for accurate models of primary productivity and global carbon cycles. A recent report in PNAS showed that sun-induced fluorescence data could be used to model gross primary productivity.** The authors found that estimates based on chlorophyll fluorescence data were much higher for major agricultural areas like the U.S. Corn Belt than models using other measures. These findings mean our current models may be underestimating how much modern agriculture and other managed areas contribute to the Earth’s carbon cycle. That report focuses on land photosynthesis, but I hope that the satellites will be collecting the chlorophyll fluorescence signal from both the land and the oceans. Let’s not forget that the photosynthetic bacteria in the ocean account for about half of the Earth’s primary productivity. I’m sure they have it covered since they have long been interested in mapping ocean color.

Check out this video for more on the OCO-2 mission.

There’s a lot of politics behind the amounts of carbon dioxide in the atmosphere, what’s causing them to creep increasingly higher and what that means for global climate patterns. Collecting accurate data on how much carbon dioxide is released into the atmosphere as well as the capacity of photosynthetic organisms to reclaim that carbon dioxide will greatly aid in global climate models that will be used to direct policy.

OCO-2 Satellite, Oh how I wonder what you will see for us. Safe journey and Godspeed.

UPDATE 07/01/14: For those of you that didn’t set your alarms early to watch the launch…

The computer has the evidence, need to abort, the countdown stops…

At T-46 seconds to be precise. There was a problem with the pad’s water system during the launch sequence that caused the mission to be aborted today. The satellite and rocket are all still ready to go, but NASA’s scientists and engineers need to figure out the source of the problem and a new launch date for the OCO-2 mission. Check here for the latest. And follow OCO-2 on Twitter!

UPDATE: 07/02/14

The OCO-2 do-over launch was successful today. Don’t just take my word for it, listen to OCO-2:



*If a launch failure happens again, I’m willing to start entertaining conspiracy theories.

**It should be noted that chlorophyll fluorescence has long been a standard technique in the laboratory for analyzing photosynthetic efficiency. Scientists have even scaled it up for field analysis. The real breakthrough in recent years has been observing this faint signal from plants via satellite using only the incident natural sunlight (not artificially bright light subjected to plants in a very controlled way).

References and Links:

Carnations: The Blanket of Champions

Today is the running of the Belmont Stakes, the third jewel in thoroughbred horseracing’s Triple Crown. This mile and a half race is known as the ‘Test of Champions,’ sorting out the speedy flashes in the pan from those that can race with endurance. Like the other two jewels of the Triple Crown, the Belmont Stakes has its own floral tradition.

Blanket of white carnations on the Belmont Stakes winner Credit: Craiglduncan via Wikimedia commons

White Carnation Credit: Dysepsion via Wikimedia Commons

White carnations are the prize of the victor. Wow. Carnations. Dianthus caryophyllus. The ubiquitous ruffled flower used as filler in almost every floral arrangement. Personally, I am not a fan of these blooms and feel they should be relegated to their place in history as boutonnieres of the 1970s. Yes, I said it. I’m sure I’m in the minority view since carnations are economically important worldwide in the floral trade. Still, you’d think the Belmont and potential Triple Crown champion would be adorned in something more lavish like orchids or plumerias to go along with the silver bowl made by Tiffany and Co. Yet it is the fundamental characteristic of the carnation as a cut flower- endurance- that deems it the most fitting ornament for the winner. Their soft colors and delicate ruffled petals belie their stamina in the vase compared to other blooms, and this is why carnations have been a mainstay of floral arrangements for centuries to the point of being unremarkable, tacky even. Analogous hardiness and perseverance in the racehorses is critical for success in the Belmont and celebrated in the form of the carnation flower.

Carnation line drawing Credit: Pearson Scott Foresman via Wikimedia Commons

As in racehorse breeding, ornamental plant breeders are seeking to combine the desirable traits of flash and fortitude. I’ve mentioned in several other posts about the genetics behind new color patterns and flower forms, but the ultimate champions in the floral industry must have stamina in the vase. This isn’t something that plants have a natural tendency to do. The purpose of flowers is to provide a desirable visual attractant to pollinators; usually insects- plants could really care less about what people think of them.* Once pollination occurs, the flower’s job is done and there’s no need for the plant to invest the energy into maintaining firm colorful petals. Thus, after pollination the flowers begin the program of senescence, in which certain cells and tissues die and fall off of the plant. Plant scientists and horticulturists are working to understand the factors involved in order to find ways to short-circuit the process and keep cut flowers alive longer in our arrangements. The complex biochemical pathways that control floral senescence make this task about as difficult as breeding a Triple Crown winner.**

White carnations are also said to represent love and luck. Sure there is a lot of love poured into the Belmont Stakes contenders. No one will discount the chance events that aided the campaigns of the three-year-old horses up to this point, but there is a great amount of dedication, training and hard work by both species contributing to success on the racetrack.

White carnation Credit: Takkk via Wikimedia Commons



“I believe luck is a concept invented by the weak to explain their failures.” –Ron Swanson




Whatever the factors contributing to the victory, the winning horse will get a blanket of white carnations painstakingly assembled by the official florist of the New York Racing Association, Tony Green and his team the day of the race. The thousands of the best-looking carnation flowers were chosen earlier this week and have been soaking in water for the past 48 hours to ensure maximum plumpness. 700 of them will be meticulously glued onto the green fabric to form the blanket for today’s winner. That’s not the only blanket that will be made today. Florists will actually be assembling another blanket to go onto the statue of Secretariat, track and world-record holder for one and half miles on dirt. Actually, there will probably even be a third carnation blanket because Secretariat’s first carnation blanket will likely wilt in the humidity before the end of the day and need to be replaced. Not even carnations have the endurance to withstand those conditions.



*Michael Pollan might disagree. Plant-human interactions have changed quite a bit and once humans become artificial plant pollinators and propagators, the selective pressure changes tremendously.

**But remember there are some advantages of plants vs. thoroughbreds when it comes to manipulating genomes. Last I checked, transgenic technology is not allowed nor is it available for thoroughbreds.

References and Links:

Adamantium, for plants!

Researchers have basically created the plant equivalent of Wolverine

Researchers have basically created the plant equivalent of Wolverine

One of the goals of photosynthesis research is to improve plants’ productivity to a level adequate for human food and energy needs. As of now, plants are currently doing a good enough job to reproduce themselves and mostly sustain our biosphere, but we would still like to kick this up a notch. Scientists are using a variety of tools to tackle this problem. The most notable is using genetics- either by breeding new varieties or genetically engineering new traits by manipulating specific genes sometimes between different organisms. Today’s post features another type of engineering to improve plants ability to photosynthesize- nanotechnology.

Researchers at MIT report that plant chloroplasts can be infused with carbon nanotubes to impart increased photosynthetic capacity (as much as 49% greater than unaltered chloroplasts and 30% in whole plants). Much like the X-Men character Wolverine was infused with the metal alloy adamantium to render his skeleton indestructible and give him those awesome retractable claws, plant chloroplasts can be infused with special materials to give them what amounts to photosynthetic superpowers. No, they didn’t use adamantium. The material used in their study was carbon nanotubes fused to cerium oxide nanoparticles aka nanoceria.*

You may be wondering to yourself, “What exactly are photosynthetic superpowers?”**

The nanoceria are able to absorb infrared light, which no native plant pigments can do. Plant pigments like chlorophylls and carotenoids do a good job of covering the visible light spectrum, but this is only half of the incident solar energy beaming down on them all day. The researchers in this study conclude that the boost in photosynthetic capacity is in part due to the fact that the nanotubes absorb light energy beyond the visible range and can then transfer this energy to the photosynthetic machinery. In this way, the nanotubes are acting like an antenna- a giant antenna that doesn’t just boost the signals you’re already getting, but allows access to a whole set of new premium channels.

The nanotubes have a couple of other advantageous side effects as well. The cerium oxide nanoparticles are quite effective radical oxygen species (ROS) scavengers. Remember when I told you photosynthetic organisms have a complicated relationship with light? They need enough of it to live, but too much can be extremely damaging. This is why blasting plants with bright light at all times isn’t necessarily the best way of improving their growth and productivity. Likewise, improving their ability to capture light can also be dangerous. This is all due to the fact that overloading the photosynthetic circuitry with too many electrons can start to generate ROS which in turn irreversibly damage proteins, pigments and DNA they encounter. Since the nanoceria are quite good at scavenging or capturing and inactivating ROS, they also boost photosynthesis by helping out plants’ innate systems for dealing with this problem. Again, like Wolverine, plants have some level of ‘healing powers’ when it comes to dealing with light, but the nanotubes help kick it up a notch. Wolverine’s adamantium doesn’t really help with his healing powers, but coating his skeleton with it means it doesn’t get broken as easily and he doesn’t have to use his healing powers to mend broken bones. In the same way, the nanoceria prevent some damage before it happens so the plants don’t have to waste their resources on repairing damage caused by ROS.

In true superhero style, the nanotube-infused chloroplasts’ powers don’t stop there. They also confer the ability to detect certain chemicals in the environment. Yes, just like Wolverine has heightened senses (if he twitches is nose, he’s knows you’re there!), chloroplasts containing nanotubes do too. Different types of nanoparticles have been developed to detect toxins and pollutants like nitric oxide, sarin gas, and TNT. Integrating this technology into a photosynthetic organism may allow plants to become stealthy biodetectors of these chemicals. No longer would they be merely scenery, but solar-powered secret agents (green-ops?) with skills no training could ever provide.***

These super powers may not be indestructible retractable claws, but it’s a good start down the path to lots of useful applications.

Conclusion: Plants infused with nanoceria definitely qualify as super photosynthesizers, but we still have some work to do to put this into useful practice beyond the lab.

How do nanoparticles and enhanced photosynthesis affect plants over their entire lifespan vs. short experiments in the lab? Does this kind of boost in the light reactions translate into an increase in biomass? Sure, the light reactions could always use some help when sunlight is less than its brightest, but the real rate-limiting pathway is the dark reactions. (I’m looking at you Rubisco!).

How can this technology be translated into field agriculture to boost productivity of crops? Is it worth it? It’s not like you can propagate the nanotubes biologically, but who knows, maybe in the future tractors will be outfitted with attachments to infuse or spray seedlings with nanoparticles. In terms of calculating potential for improving plant productivity, photosynthetic energy conversion remains a variable in the equation that has yet to be thoroughly tapped when it comes to improving crop plants. Using carbon nanotubes to extend the spectrum of useful light into the infrared would definitely help plants breakthrough some yield ceilings we are seeing.

How can we turn our scenery into useful biosensors for pollutants? What kinds of chemicals can they detect and how can that be cheaply and easily measured? Sure, everyone and their grandma has a satellite and a drone these days, but are we really going to have to laser scan our environment every hour? How about a nice color change or wi-fi signal that NORAD can detect?

Speaking of wi-fi, why can’t we engineer plants with nanotechnology that allows them to have other superpowers, like transmitting wi-fi signals? Solar-powered free internet anywhere! Finally, getting plants to release something useful besides oxygen****, and it would go a long way to keep me from going over my monthly data plan limits.

These are all questions and exciting possibilities that will keep photosynthesis researchers like the Strano lab busy for years to come.


*IMHO, ‘nanoceria’ is itself a name worthy of comic book lore. Maybe DC Comics can do a series where Swamp Thing is infused with nanoceria boosting his plant-like powers.

** You must be new here. Welcome.

***K-9 units may be relegated to history. SWAT, move over for SWNTs. (You’ll get it if you read the paper).

****It’s important to me that you catch the sarcasm in that phrase. If you’ve been breathing today, thank a photosynthetic organism.

References and Links: