Oxymoron of the Day: Nocturnal Photosynthesis

Here’s one that almost slipped by us: last month, the US Department of Energy granted $14 million to an international biofuel research team headed by the University of Nevada, with the goal of developing a new strain of poplar tree that can perform nocturnal photosynthesis. That sure sounds like a honey trap for certain pundits and federal legislators who don’t like government spending on biofuel research, especially when it scans like an oxymoron and involves spending millions on a common tree that your local nursery probably sells for less than fifty bucks. However, that relatively small investment of $14 million could make all the difference in the ability of the domestic biofuel industry to help power the US through a hotter, dryer future.

The technical name for nocturnal photosynthesis is crassulacean acid metabolism (CAM). The phenomenon was discovered back in the 1950's, when researchers at Newcastle University in the UK noted that prickly pear, agave, and some other desert plants open up their pores to absorb carbon dioxide at night, rather than during the day as in normal photosynthesis.

With a store of carbon dioxide at hand, these plants have a power source for photosynthesis during the day while keeping their pores shut tight against water loss.
According to researchers at the University of Nevada, CAM plants can thrive on 8 to 16 inches of precipitation annually, compared to typical non-CAM biofuel crops that requires 20 to 40 inches.

Why poplar? Well, as the US recovers from its corn ethanol hangover, the search is on for woody, drought-tolerant biofuel crops that don’t compete with crops for food and animal feed. That makes the ideal biofuel crop a non-food plant that can be grown on marginal land that is not suitable for cultivating food crops.
That’s where poplar comes in. Biofuel from poplars is already a hot topic in biofuel research circles because the tree grows quickly in poor soil and it tolerates dry conditions.

As a perennial biofuel crop, poplar has a potential advantage over annual crops in terms of soil conservation and energy required for cultivation.

A poplar biofuel farm could do double duty as a managed forest for wildlife habitat and recreation. Poplar is also being tested as a form of soil remediation called phytoremediation, in which plants remove contaminants from soil as they grow.

That’s all well and good, but one thing that poplar lacks is the genetic mechanism for CAM, and that is exactly what the new DOE grant is designed to give it.

Helping to nudge things along, researchers at Oregon State University have been working on a genetic modification to create semi-dwarf trees, including dwarf poplar. The idea is to keep forest US forest industries viable in a hotter, dryer world by introducing trees that are more drought-tolerant due to a larger proportion of root mass.

The increased root mass would also enhance ability of semi-dwarf trees to perform soil conservation and phytoremediation tasks.

No surprise that the Oregon State research is partly funded by the Department of Energy as well as the Department of Agriculture, the National Science Foundation, and forest industry partners.

The University of Nevada project, by the way, is titled “Engineering CAM Photosynthetic Machinery into Bioenergy Crops for Biofuels Production in Marginal Environments. The research team also includes the University of Liverpool, Newcastle University, the Oak Ridge National Laboratory, and the University of Tennessee, Knoxville.

Image: Poplar tree at night. Some rights reserved by Horia Varlan.

Photosynthesis, as it occurs?

Plants, algae and some microorganisms are phototrophs agencies because they capture light energy and used in the synthesis of carbohydrate such as glucose (formed from water and carbon dioxide). Photosynthesis is the process by which plants produce their food.

To perform photosynthesis plants need several items found in the environment.

Light energy: impacts on leaves and is absorbed by the photosensitive pigment of the plant, the chlorophyll.

Water: Photosynthesis requires a constant supply of water. It reaches the leaves through roots and stems.

Chlorophyll: Pigment green in the chloroplast. He is responsible for the absorption of light, to carry out photosynthesis.

Carbon dioxide: is absorbed by a few tiny pores called stomataon the lower part of the leaf.

Oxygen: byproduct of photosynthesis. Leaves leaves outward through the stomata.

Glucose, one of the foods they produce these agencies It is synthesized from carbon dioxide and water taken from the environment. Light energy triggers the entire process and oxygen is a waste that is released to the environment.

So the light energy can be used by plants, it must first be absorbed by them. Let's see how this happens.

On every floor we find plant pigments. Its function is absorb certain wavelengths of light, and - in his time - reflect others. The chlorophyll is one of the main pigments possessing plant. The chlorophyll absorbs light wavelengths corresponding to the violet colors, blue and red and reflects that correspond to the green. For this reason, many plants are green.

The plants have different types of chlorophyll. The chlorophyll to is the pigment that participates in the synthesis of food. Chlorophyll b and another group of pigments called carotenoids absorb wavelengths different from which absorbs the chlorophyll. These two pigments transferred power to the chlorophyll to. This phenomenon spans the spectrum of light available for photosynthesis.

The chlorophyll is found in distinct organelles in plant cells called chloroplasts, where photosynthesisoccurs. Each chloroplast there are a number of membranes containing photosynthetic pigments, the thylakoids.

In plants, the photosynthetic process occurs in two stages:

The slope of the light stage, pigments absorb wavelengths that "break" or break down molecules of water (H2O) which the vegetable incorporates the foreign environment. This stage are ion hydrogen (H +), participating in the next stage, and oxygen (O2) which is released into the environment as waste. Stage not slope of light, carbon dioxide (CO2) that the vegetable incorporates the external environment is combined with the resulting hydrogen (H +) ions in the previous stage. In this process energyis used, i.e. is an anabólica reaction and its product is glucose, a carbohydrate that stores the energy necessary for the life of plants.

I hydrogen by mimicking photosynthesis

As many know, photosynthesis is one of the activities any sort of vegetable Kingdom can generate their own food, i.e. energy, something that if took it to the demands of electric power, is precisely what is being sought from the earliest times.

Focusing on this concept, it has been announced that a new technology that plan to use a very similar to the photosynthesis system to create electricity using hydrogen is currently in full development.

As many know, one of the ways to obtain this raw is "breaking" the water molecule, although also it may be subjected to other processes to generate new hydrocarbon resembling a fossil, fuel behaviour although of course, should participation oxygen in this reaction.

In plants, acts also as an oxidizing agent, but it is quickly released in breathing, absorbing carbon dioxide, which would have to work for increased performance (for the moment, the structure of the hydrogen cell degrades)

As if this out, this would be combined also with the use of solar energy, applying directly using a blue light technology, creating a highly efficient energy conversion system.

At the moment it's all in development and is no more than a project, though it is advancing by leaps and expected results are too optimistic.