Thursday, February 28, 2008

Berry Go Round #2

The second edition of Berry Go Round, the plant-focussed blog carnival, is up at my main blog.

Tuesday, February 26, 2008

Svalbard Global Seed Vault opens

The Svalbard Global Seed Vault opened today on a remote island in the Arctic Circle, receiving inaugural shipments of 100 million seeds that originated in over 100 countries. With the deposits ranging from unique varieties of major African and Asian food staples such as maize, rice, wheat, cowpea, and sorghum to European and South American varieties of eggplant, lettuce, barley, and potato, the first deposits into the seed vault represent the most comprehensive and diverse collection of food crop seeds being held anywhere in the world.
The purpose of the repository is to preserve crop genetic diversity. I think it's an important project, but is it really enough?

Source: EurekaAlert!

Additional coverage from the New York Times.

New genetic tools for working with peas

The pea is one of many important crop species that is unsuited to the Agrobacterium-based genetic modification techniques that are commonly used to work with crops. Researchers, reporting in the open access journal Genome Biology have now discovered the first high-throughput forward and reverse genetics tool for the pea (Pisum sativum), could have major benefits for crop breeders around the world..

Researchers from the INRA Plant Genomics Research Unit at Evry, and the INRA Grain Legumes Research Unit at Bretenières, both in France, both in France developed a high-quality genetic reference collection of Pisum sativum mutants within the European Grain Legumes Integrated Project. Abdelhafid Bendahmane and colleagues used plants from an early-flowering garden pea cultivar, Caméor, to create a mutant population, which they then systematically phenotyped for use in both forward and reverse genetics studies.


Source: EurekaAlert!

Composting to fight climate change?

From EurekaAlert!
Applying organic fertilizers, such as those resulting from composting, to agricultural land could increase the amount of carbon stored in these soils and contribute significantly to the reduction of greenhouse gas emissions, according to new research published in a special issue of Waste Management & Research (Special issue published today by SAGE).

Carbon sequestration in soil has been recognized by the Intergovernmental Panel on Climate Change and the European Commission as one of the possible measures through which greenhouse gas emissions can be mitigated.

One estimate of the potential value of this approach – which assumed that 20% of the surface of agricultural land in the EU could be used as a sink for carbon – suggested it could constitute about 8.6% of the total EU emission-reduction objective.

“An increase of just 0.15% in organic carbon in arable soils in a country like Italy would effectively imply the sequestration of the same amount of carbon within soil that is currently released into the atmosphere in a period of one year through the use of fossil fuels,” write Enzo Favoino and Dominic Hogg, authors of the paper.

The number - 0.15% - seems small, but this is deceptive - it's still an awful lot of carbon. I'd be more interested in the mechanics of how they're going to get this done...but that would probably require actually reading the journal. The press release addresses an important point

However, capitalizing on this potential climate-change mitigation measure is not a simple task. The issue is complicated by the fact that industrial farming techniques mean agriculture is actually depleting carbon from soil, thus reducing its capacity to act as a carbon sink.

but answers this by saying

According to Hogg and Favoino, this loss of carbon sink capacity is not permanent. Composting can contribute in a positive way to the twin objectives of restoring soil quality and sequestering carbon in soils. Applications of organic matter (in the form of organic fertilizers) can lead either to a build-up of soil organic carbon over time, or a reduction in the rate at which organic matter is depleted from soils. In either case, the overall quantity of organic matter in soils will be higher than using no organic fertilizer.
Let us hope it's that simple.

Draft corn genome

A team of scientists led by Washington University in St. Louis has begun to unlock the genetic secrets of corn, a crop vital to U.S. agriculture. The researchers have completed a working draft of the corn genome, an accomplishment that should accelerate efforts to develop better crop varieties to meet society's growing demands for food, livestock feed and fuel....
The genetic blueprint will be announced on Thursday, Feb. 28, by the project's leader, Richard K. Wilson, Ph.D., director of Washington University's Genome Sequencing Center, at the 50th Annual Maize Genetics Conference in Washington, D.C.
Source: EurekaAlert!

Related: from Iowa State University News Service: Iowa State researchers help piece together the corn genome's first draft

Also, from PhysOrg.com

Friday, February 22, 2008

Invasive plant journal launched

The Weed Science Society of America has launched a new journal, Invasive Plant Science and Management. The first issue is expected in the first quarter of 2008. The society is soliciting articles in:

[T]he biology and ecology of invasive plants in rangeland, parkland, prairie, pasture, preserve, urban, wildland, forestry, riparian, wetland, aquatic, recreational, rights-of-way, and other non-crop settings; genetics of invasive plants; social, ecological, and economic impacts of invasive plants; design, efficacy, and integration of control tools; land restoration and rehabilitation; effects of management on soil, air, water, and wildlife; scholarship in education, extension, and outreach methods and resources; technology and product reports; mapping and remote sensing, inventory and monitoring; technology transfer tools; and regulatory issues.

Thursday, February 07, 2008

A guardian of grasses

Anoop Sindhu and colleagues report on a gene that may have played a key role in the evolution of grasses. The gene, Hm1, provides resistance against Cochliobolus carbonum race 1 (CCR1), a fungus that is capable of attacking and killing corn at any stage of its development (images of CCR1 infection). While CCR1 is only known to affect corn, the gene Hm1 and its relatives are present throughout the grass family, but are absent from other lineages.

CCR1 is only known as a disease in Zea mays, but the Hm1 family of genes throughout the grass family. Sindhu and colleagues silenced the corresponding gene in barley. This resulted in barley that was susceptible to CCR1. The fungus is able to invade susceptible grasses through the production of Helminthosporium carbonum* (HC) toxin. The ability of Hm1 and related genes to resist CCR1 comes from an enzyme known as HC-toxin reductase (HCTR), which detoxifies HCTR.

A phylogenetic analysis of the Hm1-gene family showed that they were monophyletic - they all shared a common ancestor. Since it is present throughout the grass family, but is absent from all other groups of plants, it appears that the gene shares its origin with the grass family. This lead the authors to conclude that:

The maintenance of HCTR gene function in maize and barley, coupled with the unique phylogenetic position of the Hm1 gene (with no closely related orthologs in eudicots), suggests that Hm1 may have played a critical role in the evolution of most of our cereal crops. Given the devastating potential of CCR1 to kill susceptible corn, it is likely that this fungus or its ancestral form would have threatened the existence of grasses, or at least severely constrained their geographical distribution, had Hm1 not evolved to detoxify HC toxin. Thus, it seems likely that Hm1 served as a guardian of the grass family, allowing it to survive, thrive, and evolve into crops that feed the world.
*Helminthosporium carbonum is the asexual form of Cochliobolus carbonum. Since fungi are classified on the basis of their sexual structure, fungi whose fruiting bodies are unknown often end up being described as distinct species.

Sindhu, A., Chintamanani, S., Brandt, A.S., Zanis, M., Scofield, S.R., Johal, G.S. (2008). A guardian of grasses: Specific origin and conservation of a unique disease-resistance gene in the grass lineage. Proceeding of the National Academy of Sciences USA, 105(5), 1762-1767. DOI: 10.1073/pnas.0711406105 Open Access

Wednesday, February 06, 2008

Onions without tears

Using gene silencing, researchers in New Zealand's Crop and Food research institute were able to make onions that don't make you cry when you cut them.

Source: PhysOrg.com

Eat your carrots - you need the calcium

Food science tends to focus on improving the nutritional quality of foods, but rarely does it look at how these "improved" foods affect human (or animal) health. A group of researchers from Texas A&M University and Baylor College of Medicine looked at whether enriched calcium in foods was actually used by the body. They had previously engineered carrots which had twice the normal level of calcium. In a paper published in the Proceeding of the National Academy of Sciences USA, they looked at the fate of this calcium in the body. By using labelled calcium they were able to observe its eventual fate. Their conclusion:
In a cross-over study of 15 male and 15 female adults, we found that when people were fed sCAX1 and control carrots, total calcium absorption per 100 g of carrots was 41% ± 2% higher in sCAX1 carrots. Both the mice and human feeding studies demonstrate increased calcium absorption from sCAX1-expressing carrots compared with controls. These results demonstrate an alternative means of fortifying vegetables with bioavailable calcium.
Morris,Jay, Hawthorne,Keli M., Hotze, Tim, Abrams Steven A., and Hirschi*, Kendal D. 2008. Nutritional impact of elevated calcium transport activity in carrots. Proceeding of the National Academy of Sciences USA 105(5):1431-1435 DOI:10.1073/pnas.0709005105

Friday, February 01, 2008

Is it really organic?

It can be difficult to determine whether something is really organic. How can you tell if a producer is calling food organic that isn't? While most persticides are likely to leave residues that could be tested for, fertilisers are more difficult to detect. One possibility is to look for differences in the ratios of stable isotopes of nitrogen - nitrogen. Spanish scientists Francisco del Amora, Joaquín Navarroa and Pedro Aparicio decided to see if they could tell the difference between organic and conventionally grown crops on the basis of nitrogen isotope ratios. They concluded that it was possible to detect fertiliser use.
Agencies for organic farming certification require techniques to verify the organic nature of the N fertilizers applied to crops. Results show that significant differences have been found between organic and not fully organic practices. Thus, this study demonstrates that with N-isotopic techniques it is possible to discriminate the use of chemical fertilizers in the organic production of sweet peppers with respect to strictly nonorganic crops. Further studies including the effects of different soils characteristics, climate, and biotic or abiotic stress could be useful in determining the proper interval of 15N/14N ratio to exclude nonorganic fertilization practices.
del Amora,F.M., Navarroa J., and Aparicio, P.M. 2008. Isotopic Discrimination as a Tool for Organic Farming Certification in Sweet Pepper.