Agronomia

ScienceDaily (Mar. 29, 2011) — Scientists in the United States and the United Kingdom have been awarded funding totaling more than $10.3 million to improve the process of biological photosynthesis. The U.S. National Science Foundation (NSF) and the U.K. Biotechnology and Biological Sciences Research Council (BBSRC) collaborated in issuing these jointly funded awards.

Photosynthesis allows biological systems to use sunlight and carbon dioxide to produce sugars and oxygen. This process is ultimately responsible for the food we eat and the fossil fuels we burn today.

Four transatlantic research teams will explore ways to overcome limitations in photosynthesis that could lead to the development of new methods for significantly increasing the yields of important crops for food production and/or sustainable bioenergy.

The funding agencies used a novel method called an "Ideas Lab" that led to these awards. Ideas Labs are based on the "Sandpit" concept initially developed by the Engineering and Physical Science Research Council (EPSRC) and are designed to stimulate new conversations about old problems.

In September 2010, an Ideas Lab was held in Asilomar, Calif. that focused on stimulating thinking in promising new, or currently under-developed, research areas relevant to photosynthesis. The workshop's goals were to develop innovative and transformative ideas on how to enhance photosynthesis through a multi-disciplinary approach and to bring together researchers to explore new and exciting avenues for future research in photosynthesis across all disciplines.

The result was the generation and real-time review of high-risk but potentially high-impact proposals for increasing the efficiency of photosynthesis.

NSF and the BBRC are now releasing four awards for proposals--each of which addresses a different bottleneck in photosynthesis--that were produced through the alternative approach pioneered at the Ideas Lab. NSF is contributing a total of $5.2 million to support U.S. participants in these projects.

"Photosynthesis is essential for life on Earth," said Joann Roskoski, NSF's acting assistant director for Biological Sciences. "By providing food and generating oxygen, it has made our planet hospitable for life. This process is also critical in addressing the food and fuel challenges of the future. For decades, NSF has invested in photosynthesis research projects that range from biophysical studies to ecosystem analyses at a macroscale. The Ideas Lab in photosynthesis was an opportunity to stimulate and support different types of projects than what we have in our portfolio in order to address a critical bottleneck to enhancing the photosynthetic process."

BBSRC's Director of Research Janet Allen said, "Photosynthesis has evolved in plants, algae and some other bacteria and in each case the mechanism does the best possible job for the organism in question. However, there are trade-offs in nature which mean that photosynthesis is not as efficient as it could be--at around only five percent, depending on how it is measured. There is scope to improve it for processes useful to us by, for example, increasing the amount of food crop or energy biomass a plant can produce from the same amount of sunlight. This is hugely ambitious research but if the scientists we are supporting can achieve their aims it will be a profound achievement."

Joanne Tornow, NSF's acting executive officer for Biological Sciences added that "The Ideas Lab is an innovative method for generating new ideas and building new teams of researchers that will undertake potentially transformative projects in areas of high impact, such as photosynthesis. Although NSF's award portfolio is already filled with exciting investments that hold great potential for advancing the frontiers of knowledge, trying new approaches could result in expanding the portfolio in new and unanticipated ways."

The four projects that were selected for funding at the Ideas Lab will conclude in about three years.

"The world faces significant challenges in the coming decades--and chief among these is producing enough sustainable and affordable food for a growing population and replacing diminishing fossil fuels," said Allen. "Even a small change to the efficiency of photosynthesis would make a huge impact on these problems. As these are global challenges, it is apt that we are working across national and scientific boundaries to put together truly international and multidisciplinary research teams."

When the four funded projects conclude, the two funding agencies will examine the approaches taken by these projects for addressing photosynthetic energy in order to determine whether the Ideas Lab approach realized its potential to generate novel and potentially transformative outcomes.

Summaries of the four funded projects follow:

1. Plug and Play Photosynthesis led by Anne Jones of Arizona State University: This project is designed to separate the capture and conversion of solar energy into fuel--processes that may be completed by a single cell--into two different organisms that would communicate with one another through electrical currents flowing between them. This separation of photosynthetic processes into different organisms will enable researchers to optimize environments for each of these processes and thereby improve their efficiency.
2. Exploiting Prokaryotic Proteins to Improve Plant Photosynthesis Efficiency (EPP) led by Stephen Long of the University of Illinois: A metabolic process known as photorespiration reduces the yields of plants including major crops, such as soy, wheat and rice, by an estimated 20 percent to 50 percent. Some blue-green algae have protein structures, called carboxysomes, that reduce such losses. This research aims to adapt and engineer these protein structures into crop plants to minimize photorespiration and boost yield.
3. Multi-Level Approaches for Generating Carbon Dioxide (MAGIC) led by John Golbeck of Pennsylvania State University: Through this project, researchers will attach to the membranes of photosynthesizing cells special proteins that will pump carbon dioxide from the atmosphere into cells. Resulting increases in the availability of carbon dioxide inside these cells will inhibit photorespiration and promote photosynthesis.
4. Combining Algal and Plant Photosynthesis (CAPP) led by Martin Jonikas of Stanford University: The unicellular green alga Chlamydomonas has a pyrenoid--a ball-shaped structure within the cell that helps this algae assimilate carbon to improve its photosynthetic efficiency. The goal of this project is to characterize the pyrenoid and associated components, and transfer them to higher plants in order to improve their photosynthetic efficiency.

A new domain of life

 

 

Mar 24th 2011 | from the print edition

LIFE, like Caesar’s Gaul, is divided into three parts. The Linnaean system of classification, with its prescriptive hierarchy of species, genus, family, order, class, phylum and kingdom, ultimately lumps everything alive into one of three giant groups known as domains. The most familiar domain, though arguably not the most important to the Earth’s overall biosphere, is the eukaryotes. These are the animals, the plants, the fungi and also a host of single-celled creatures, all of which have complex cell nuclei divided into linear chromosomes. Then there are the bacteria—familiar as agents of disease, but actually ecologically crucial. Some feed on dead organic matter. Some oxidise minerals. And some photosynthesise, providing a significant fraction (around a quarter) of the world’s oxygen. Bacteria, rather than having complex nuclei, carry their genes on simple rings of DNA which float around inside their cells. The third great domain of life, the archaea, look, under a microscope, like bacteria. For that reason, their distinctiveness was recognised only in the 1970s. Their biochemistry, however, is very different from that of bacteria (they are, for example, the only organisms that give off methane as a waste product), and their separate history seems to stretch back billions of years. But is that it? Or are there other biological domains hiding in the shadows—missed, like the archaea were for so long, because biologists have been using the wrong tools to look? That is the question asked recently by Jonathan Eisen of the University of California, Davis, and his colleagues. They suspect there are, and in a paper just published in the Public Library of Science, they present an analysis which suggests there might indeed be at least one other, previously hidden, domain of life. What I did on my holidays The data from which this conclusion was drawn were collected between 2003 and 2007 on one of the most scientifically productive holidays in history. This was a round-the-world cruise taken by Craig Venter on his yacht, Sorcerer II, which studied the diversity of micro-organisms in the Atlantic, Pacific and Indian oceans. Dr Venter was working out his frustrations after having been fired in 2002 from Celera Genomics, a company he helped set up in 1998 with the specific aim of sequencing the human genome faster and better than the public Human Genome Project was managing at the time. In that, it succeeded. In the wider aim of turning such knowledge into hard cash, however, it was nowhere near as successful as its financial backers had hoped. Dr Venter therefore found himself with more time on his hands than he had been planning. His killer app in Celera’s assembly of the human genome was a technique called shotgun sequencing. This first shreds a genome into pieces small enough for sequencing machines to handle, then stitches the sequenced pieces back together by matching the overlaps using a computer. In principle, he realised, that trick could be used on mixed DNA from more than one organism. A good enough program would stitch together only fragments from the same type of creature. This would allow you to see what was living in a sample without having to culture anything. And since a huge majority of micro-organisms (by some estimates, 97%) cannot be cultured, that sounded like a great idea. Metagenomics, as the new technique is known, has vastly extended knowledge of what bugs live in the sea—and in many other places, from hot springs to animals’ guts. It is not perfect. In practice a lot of what emerges are fragments of genomes, rather than complete assemblies. But it has been enormously successful at identifying previously unknown individual genes. Dr Eisen wondered if it could be pushed still further. He started combing through the data from the cruise to look for new forms of genes that have, in the past, proved useful in distinguishing bacteria, archaea and eukaryotes from each other, to see if there are any other domains of life out there. After a false start pursuing what are known as ribosomal RNA genes—which are involved in protein synthesis and are believed by some people to be the genetic core around which the rest of life accreted—he lighted on two genes called RecA and RpoB. RecA is involved in DNA recombination. RpoB is involved in translating DNA into RNA. Both, like the genes for ribosomal RNA, are old and ubiquitous. And lo, when he drew trees that tracked the evolutionary relationships between all the RecAs and all the RpoBs found on the cruise, he discovered parts of the trees that did not fit with the pattern established by known versions of these genes in the public genetic databases. Some of these novel branches were, nevertheless, similar enough to known branches to be accounted for as known unknowns. But both RecA and RpoB had one branch that really was an unknown unknown. Neither of these branches fits in the existing tree of life. And that is a mystery. It may be that they belong to some as-yet-uncharacterised group of viruses (entities classified outside Linnaeus’s system, since there is no agreement about whether they are alive or not). Or it may be that they belong to a fourth domain of living organism. Either way, it suggests a profound lacuna in biologists’ understanding of the world. The question is, is it a big lacuna as well as a deep one? Is the new group an important part of the biosphere? That is hard to say at the moment. The genes concerned are rare in the overall metagenomic analysis, so creatures carrying them may not be abundant. On the other hand, those creatures might just be too small to be caught easily by the filters used to winnow life from water for analysis in the first place. As to importance, when originally identified as distinct, the archaea, too, were regarded as marginal—yet their methane-generating properties are now a factor in climate-change calculations. If the new domain is real, it must have been around for several billion years, and must thus have something going for it. What that something is remains to be seen. from the print edition | Science and Technology