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A gene to limit the accumulation of Cadmium (toxic) in rice

Nessun commento September 22, 2010 No comments

The 'intake of cadmium (Cd) via contaminated rice, because of serious and sensational effects, such as Itai-Itai syndrome, he remains a great risk to human health: it is thought that the average concentration of cadmium is increasing, and this seems mainly related to soil contamination related to industrial production.

The disease has been detected for the first time in 1946 in a region of Japan, and its name is due to the intense pain that causes rheumatoid and myalgic ("Itai itai" is in fact a cry of pain equivalent to "ouch ouch") . In addition to serious kidney damage, the disease also leads to alterations in the metabolism of calcium and phosphorus, some Ca 2 + ions are replaced by bone Cd 2 +, which possess the same electrical charge and roughly the same size, take the bones, with time, a porous appearance and may fracture. ( Source )

In addition to strict controls on industrial discharges of heavy metals in soil, a possible strategy to address toxic cadmium intake via food may be the creation (or selection) of rice varieties that are not able to take this element .

In this view you insert a new study by researchers at Okayama University of Japan, which has led to the identification of a gene of rice (OsHMA3) responsible for a low accumulation of cadmium, the gene was isolated through a series of experiments cross between rice varieties with low and high accumulation of Cd.

Localization of the transporter with Cd and GFP antibodies. For more details click on the image

The gene in question encodes a transporter belonging to the family 1B P-type ATPase, but shows little similarity with other members. The heterologous expression in yeast showed that the carrier of the variety low accumulation of Cd is functional, whereas that resulting from the variety high accumulation of Cd has lost its function, probably due to the mutation of a single amino acid.

The transporter is expressed mainly in the tonoplast of root cells, with similar levels of expression in both varieties of rice. Overexpression of a functional gene (from the rice variety "low-Cd") generates a selective decrease of the accumulation of Cd, but not of other micronutrients in the caryopsis.

All these results indicate that the gene variant OsHMA3 from the "low-Cd Accumulating" limits the translocation of cadmium from roots to upper tissues, selectively sequestrandolo inside the vacuoles of roots.

Source: Pnas.org
Categories: Agronomy

Cloves: best natural antioxidants

1 commento March 16, 2010 a comment
The spices typical of the Mediterranean diet, with natural antioxidant activities, are increasingly used in the food industry on a large scale, in virtue of which have beneficial effects on health.

Researchers at the University Miguel Hernández (UMH), Elche (Spain) have identified cloves ( Syzygium aromaticum ) as the most powerful antioxidant spice, by virtue of the fact that they contain high levels of phenolic compounds (in particular eugenol ), in addition to many other features.

"Among the 5 different antioxidant capabilities that we tested, cloves have demonstrated the highest ability to reduce lipid peroxidation and to be the best reducing agent of iron, "says Juana Fernández-López, one of the authors of the study .

"The findings suggest that the use of these spices typical of the Mediterranean diet, or extracts thereof, may be a new way forward in the food industry, to the extent that they are not altered the organoleptic properties of food products. These substances exhibit strong antioxidant capacity, and can provide strong health benefits. "

The research team also confirmed the antioxidant effects of essential oils from other spices, like oregano (Origanum vulgare), thyme (Thymus vulgaris), rosemary (Rosmarinus funcionarios cinalis) and sage (Salvia funcionarios cinalis). The objective of this study was precisely to allow the incorporation of these spices in food, especially in the flesh as natural antioxidants.

The food industry could definitely replace synthetic antioxidants with these spices

"The oxidation of lipids is one of the main reasons why the food deteriorates, and causes a significant reduction in their nutritional value, besides the loss of original flavor," says Fernández-López.

Eugenol, extracted essential oil of cloves, has strong antioxidant properties

These alterations lead to a reduction in the duration of life of finished food products: To avoid this deterioration, the food industry uses synthetic antioxidants in the production process. Obviously, as these are synthetic chemical compounds, there are many questions about their potential toxicity and possible side effects.

So the increased interest in natural antioxidants (derived from aromatic and medicinal plants and spices) is oriented to that hope that synthetic antioxidants used in the food industry can be replaced by these substances without a doubt "more natural".

Source: EurekAlert!
Categories: Agronomy

New study puts the origin of angiosperms 215 million years ago

Nessun commento March 15, 2010 No comments
According to a new study plant evolutionary tree, flowering plants may be considerably older than previously thought, and have appeared for the first time in the middle Triassic

Till now it was commonly accepted in the scientific community that the flowering plants, or angiosperms , they made ​​their first appearance on Earth between 140 and 190 million years ago, a new study by scientists at the National Evolutionary Synthesis Center (NESCent) of Durham, North Carolina, now brings to anticipate the appearance of the first angiosperms about 215 million years ago, which is something like 25 to 75 million years earlier than suggested by the most ancient archaeological or previous molecular studies.

The "Liaoning ancient fruit", one of the oldest flower fossil, dating back some 145 million years ago

Says Michael Donoghue of Yale University: "If we look only to archaeological finds, we could determine the rise of angiosperms in the late Jurassic or early Cretaceous."

He adds Jeremy Beaulieu, a biologist at Yale: "Despite the archaeological data, the majority of molecular divergence times indicates that angiosperms must have come about earlier: our study led us to define the Triassic period as the source. No one else has ever previously found such a result "

Recall that all three geological periods mentioned above are part of 'was secondary or Mesozoic, ranging from 251 million years ago to 65 million years ago, and which is in turn divided into three periods Triassic (251 to 200 million years ago), Jurassic (200 to 145 million) and Cretaceous (145 to 65 million years ago - is at the very end of this period came the extinction of the dinosaurs, as well as over 70% of all species).

If repositioning the timescale of the appearance of angiosperms were confirmed, could reinforce the idea that the first plant of this type may have promoted the development of certain species of insects: for example, insects such as bees and wasps still rely on their survival nectar and the pollen found on flowers.

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Categories: Agronomy

New discovery: how legumes can free ourselves from fertilizers

1 commento March 11, 2010 a comment
The increasing use of nitrogenous fertilizers in agriculture as pertaining between the main sources of pollution and possible causes of global warming, but a new discovery by researchers at Stanford University could reverse this trend, with great benefit to the environment.

Nitrogen is an essential element for life of all plants, but our planet is paying a price much too high because of the massive use of nitrogen fertilizers, when these substances are dispersed in rivers and lakes surrounding the cultivated fields, cause a huge colonization by algae, which completely destabilize these aquatic ecosystems, making them desolate areas deficient in oxygen and therefore devoid of any life form (except for the same algae and bacteria).

Mississippi Dead Zone: Red and orange areas are those with a lower concentration of dissolved oxygen.

The process is called eutrophication , and a serious and sad example of the effects of the condition of hypoxia (lack of oxygen in the environment) is provided by the "Dead Zone" ( Dead Zone ) which covers 9300 km 2 in the Gulf of Mexico (equivalent to a region like the Marche to be clear ..), where no aquatic organism can survive for advice about a good article in the Corriere della Sera, drawn 12 years ago now - the cathedrals of coral collapse (July 12, 1998 )

What's more, fertilizers release nitrous oxide gas ( N 2 O , also known as nitrous oxide), which is a potent greenhouse gas, through its effect on the climate that we can easily imagine.

The new discovery of Stanford researchers shed light on the mechanism by which leguminous plants (soybean, peas, chickpeas, beans, lentils, to name a few) are able to induce nitrogen-fixing bacteria that live in their roots, to produce, from of molecular nitrogen N 2, ammonia and nitrogen compounds, essential nutrients for the plant which lives in symbiosis (for details see nitrogen fixation - Wikipedia ).

The greater understanding of the process can lead to applications that increase agricultural productivity, while reducing the use of nitrogen fertilizers.

Says molecular biologist Sharon Long: "We have discovered a new biological process, by which leguminous plants control the behavior of symbiotic bacteria. These plants have a specialized protein processing system, which generates signals spefici protein. These were unknown until now, but now transpires with all the evidence that they are critical to determine the nitrogen fixation by the bacteria. "

The ability of legumes to capture nitrogen from the air and turn it into nutrients (fixing it, in fact) also leaves the soil enriched by the nutrients contained in the waste of the plant that remains on the soil after harvest, creating a natural fertilizer for the next crops.

This indeed is the basis of crop rotation: the alternation between legumes and other crops in the past has been the cornerstone of agriculture around the world for thousands of years. Only recently, however, has begun to understand how it worked fixation, and why some legumes are more efficient than others in this process.

The key point of the research conducted by the team of Long a gene of the plant is essential for the formation of a precise chemical signal, in the absence of which the nitrogen is not fixed in any way by the symbiotic bacteria.

The nitrogen-fixing bacteria are a source of nourishment provided for legumes

Nitrogen-fixing bacteria (left) and root nodules in which they reside (right)

The symbiotic bacteria reside within the root nodules of leguminous plants, which capture the molecular nitrogen in the soil and convert it into ammonia, which feeds on the plant: only bacteria that possess the enzyme nitrogenase are capable of nitrogen fixation, and Therefore only plants that host nitrogen-fixing bacteria have such easy source of nutrients. All other plants are forced to use as a source of organic nitrogen compounds nitrogen already present in the soil, and it is precisely this logic that you employ the nitrate.

This particular feature allows legumes to be able to thrive in poor soil of nitrogen, less fertile for other plants, but only if its root nodules contain in the right symbiotic bacteria.

"Especially since it raises the efficiency of production of pulses and the range of land where we can grow them, the more they can help reduce the use of industrial fertilizers, and thereby reduce water contamination and decomposition in the form oxidized gaseous "Announces Long.

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Categories: Agronomy

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