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Another discovery brings GMOs to the bench

Another discovery brings GMOs to the bench

Discovering Entre Ríos: Entre Ríos Lajmanovich explains the seriousness of the case.

Conicet and the UNL discover the toxicity of a bacterium widely used to fight mosquitoes, and which was introduced by genetic manipulation in Bt maize, widely distributed in the country

Tirso Fiorotto / From the UNO Staff

Stimulated by profit, man reaches into the ecosystem without knowing, and distorts everything.

With the excuse of killing mosquitoes and controlling butterflies, whose larvae feed on leaves or stems of crops, the companies end up affecting San Antonio vaquitas (the so-called benefics), frogs, worms, generating resistance in some insects, or promoting development of others.

All of this has an impact on the health of the human species itself, and sometimes directly, because that same search for profit leads to changing genetics in seeds and incorporating bacteria that, ultimately, it is not well known how they will evolve. strength in a place that is not yours.

Not counting what the contamination of all seeds with organisms modified by man means for the planet and the consequent loss of biodiversity on the altar of a uniformity that, thanks to the propaganda of the system, is becoming naturalized.

Massive impact?

The Conicet researcher from Entre Ríos Rafael Lajmanovich commented, at our request, the relevance of a research work that points to transgenics, just when our country is approving genetic modifications in corn.

Scientists, among whom is Paraná, suggest in this work that toxins can have a massive impact on ecosystems, without excluding damage to people's food.

The warning alone, originating from people who know, should generate responses in all areas, starting with governments and multinationals.

Lajmanovich is Full Professor of the Chair of Ecotoxicology at the Faculty of Biochemistry and Biological Sciences of the National University of the Litoral. For decades this man from Entre Ríos has studied embryos, mainly frogs, and warns and reports the negative impact suffered by chemicals used in agriculture.

He is also studying, with other researchers, the pesticide use of bacteria such as Bacillus thuringiensis (Bt). The work that we report here, released this month, was carried out by researchers Celina Junges, Mariana Cabagna Zenklusen, Andrés Attademo, Paola Peltzer, Mariana Maglianese, Vanina Márquez, Alejandro Beccaria and Rafael Lajmanovich himself.

Their names themselves, and the membership of some of the Conicet or the UNL, indicate that we are at the top of Argentine science.

In their conclusions, the experts state that exposure to the commercial formulation of the Bt bacillus, even at low concentrations and for a relatively short period, can induce genotoxicity and intestinal damage in tadpoles of the common frog. In a system already hampered by agribusiness, how much more will species suffer? And how much should it serve as a warning, in view of the health of the same human being who breathes in the sprayed chemicals, and eats the modified corn seeds, already with the bacteria forced into the same children's plate?

An insecticide to fear

The research recalls that the global use of pesticides amounts to about two million tons per year. Half of the pesticide trade involves biopesticides, and more than 60% of this trade is related to Bacillus thuringiensis.

Bacillus thuringiensis (Bt) is a common soil bacteria. Its spores contain proteins toxic to certain insects. These proteins, called "Cry" or parasporal crystal, are activated in the digestive system of the insect and adhere to its intestinal epithelium. Thus they provoke the formation of pores in the larval digestive tract, alter the osmotic balance of the intestine. From there to the paralysis of the insect's digestive system, which no longer feeds and dies.

In recent years, Bt genes have been used for the production of genetically modified organisms (GMOs), that is, crops resistant to insects. For example, Bt corn with recognized properties against insects such as the so-called borers.

Bt corn is today one of the most widespread crops in our region, and in the world.

The Bt israelensis (Bti) variety is used throughout the world for its efficacy in mosquito control, and is one of the most recommended methods for dengue vector control.

It is no small thing. Scientists recall that in the world 70 to 300 metric tons of formulated product are used per year for this purpose. Until now, research allowed to affirm that Bti was harmless to non-target organisms, that is, those to which it is not directed, due to its way of acting (within the intestine).

However, other authors already saw that the effects of Bti on amphibians had received little attention, and pointed out that the tests used to justify approval for the use and release of Bt products on the market, as well as the protocols that are used to assess their toxicity, they were extremely superficial.

There is an additional fact: “Bt-based products are distributed in different types of formulations in many countries. The core content is mixed with additives, wetting agents, adhesives, sunscreens and synergistic agents… These additives listed as ‘inert’ ingredients on the labels remain a trade secret by the manufacturers of the products ”.

Thus, the formulations contain concoctions other than Bt that can enhance toxicity. "The toxicity of larvicidal Bti-AS can be strengthened by the presence of dangerous components contained in the so-called inert ingredients incorporated in pesticide formulations," it reads.

Damage to tadpoles

“The present study shows several histological alterations of the intestinal epithelium in the treated tadpoles. Two histological symptoms are distinguished at all Bti-AS concentrations: infiltration into the connective tissue underlying the epithelium and dilation of the blood vessels. Both epithelial alterations are considered as defense mechanisms of organisms against a stress factor. This interpretation is supported by observations in surviving tadpoles, which showed only the moderate forms of intestinal dysplasia.

In many cases the defense reactions of the larvae were insufficient… It is not clear at the moment if the intestinal damage is reversible in tadpoles ”.

About this latest contribution from scientists, published in English in Elsevier, a leading publisher in the dissemination of health research, Lajmanovich said: “We demonstrate the potential genotoxicity and effects on the digestive system of animals of Bacillus thuringiensis. Its toxins are used to control mosquito larvae and it is currently part of GMOs (genetically modified organisms), especially the well-known Bt corn.

There is an intense scientific debate about the potentiality (of Bt corn) to produce ‘genetic contamination’ in Creole maize, and about the Cry toxins of BT about their apparent ‘no harm’ for vertebrates (animals and humans) ”.

The studies carried out in tadpoles of Leptodactylus latrans (Creole frog) were, as can be seen, of enormous utility and will provoke new debates around insecticides and genetic manipulation.

Dangerous crosses

The magazine of the Grupo Semillas de Colombia published a study on the genetic contamination of the races of Creole maize in the north of South America.

“Corn is a cross-pollinating plant. Pollen is viable 24 hours and is dispersed by the wind and animals. A corn plant releases 14 to 50 million grains of pollen. Several studies carried out on the distance to which corn pollen is transported by the wind show that with slow to moderate winds, a high concentration of pollen occurs 1 meter from the source; 2% reaches 60m; 1.1% at 200m, 0.5% at 500m and 0.2% at 800m.

If carried by insects: pollen travels several kilometers. In strong winds, pollen can travel up to 180 km. The European Environment Agency considers that maize has "medium to high risk" for gene transfer to other plants of the same species.

Additionally, the Technological Institute of Agrarian Management of Navarra (Spain) found dispersion of corn pollen at distances of at least 500m. A study by the UK National Pollen Research Unit pointed out that the percentage of pollen flow and maize crossing that occurs at a distance of 600m is 0.8% and at 800m 0.2% ”.

“These data show the real danger that transgenic corn pollen can contaminate native varieties from the centers of origin, as it was presented in Mexico. Also the contamination of local and conventional varieties from countries like Colombia, which are centers of corn diversity. In the case of Mexico, several analyzes have shown that a large part of the native seeds of indigenous and peasant communities are contaminated with transgenic corn imported from the United States. This situation has generated a strong mobilization and rejection on the part of Mexican organizations, through campaigns and actions in defense of the culture of corn ”.

“Colombia has a great diversity of native maize, of which hundreds of varieties belonging to 23 races have been referenced, especially in the Caribbean region and in the Andean region, which are the areas where indigenous and peasant communities have conserved and managed them ( for example: blue corn, cariaco, negrito, pebble, gallo's eye, horse tooth, clavito, mountaineer, puya and chamí, among others.) These corn have been the fundamental basis for food sovereignty, especially of rural populations. One of the main dangers that would have to introduce transgenic maize in Colombia, is that the genetically modified genes are transferred towards the creole varieties and contaminate them, thus losing the original characteristics of this important genetic patrimony of the country ”.

System gifts

Monsanto and other multinationals are primarily responsible, with the governments that authorize their patents, for the environmental risk of genetic manipulations.

“RoundUp Ready (RR) corn - Colombians say - has been genetically modified to express tolerance to Monsanto's glyphosate herbicide. One of the main concerns of releasing this maize in Colombia is the transfer of the genes that give this resistance characteristic to the native maize or to the grass weeds close to this species, which could generate new herbicide-resistant weeds.

It would be almost impossible to prevent this situation from occurring, both due to environmental conditions or due to the use, management and exchange of corn carried out by rural populations. Once the transgenic corn circulates freely within the country, either via imported food or through commercial crops, it is not possible to carry out a control that prevents the entry of this type of corn to the different regions and communities in which corn is grown and inevitably, sooner or later their landraces will be contaminated ”.

"Bt corn is a variety that has been introduced to genes from a soil bacterium called Bacillus thuringiensis. This bacterium produces a toxin that controls some insect pests of the Lepidoptera family (butterflies). When a Bt corn crop is commercially released in a country like Colombia, several events could occur, among which we can list: pests could acquire resistance to the Bt toxin, due to permanent exposure to the toxin (during the entire cycle culture). This has already happened in conventional agriculture due to the abuse of insecticides, a problem that could be exacerbated with the massive use of Bt crops ”.

“The Bt toxin, under the conditions of a transgenic crop, is permanently found in the plant. This means that the plant becomes a biopesticide, which is produced throughout the crop cycle and in a higher concentration than when said toxin is applied in a sprayed way. In addition, we are talking about the ability of the toxin to reproduce itself within a living being that is transmitted from one generation to the next. Therefore, the competent authorities in the field of biosafety, both in the United States and in Europe, require a much stricter evaluation for Bt crops compared to other types of transgenic crops ”.

“Another event that could occur with a Bt crop is that by controlling a primary pest, secondary pests that are not controlled by the crop toxin become primary pests. This would cause a greater quantity of insecticides to be used for its control, a situation that has already occurred in China with the cultivation of Bt cotton after 5 years of cultivation and evaluation, between 1997 and 2001 ”.

"In addition, the toxins produced by these plants can affect beneficial insects that help control pests in crops."

“In Switzerland, an experiment with larvae of Lacewing carnea revealed that their mortality doubled when they consumed larvae of borers fed with Bt maize from Novartis. In the United Kingdom, in a study with coccinellids, which are pest controllers, it was found that they were affected by the Cry 1Ab toxin in Bt maize. Additionally, there may be impacts on soil microorganisms from crop residues and exudates in the soil of Bt crops.

In the world, not enough studies have been carried out to evaluate these possible effects and their impact on ecosystems. A study conducted at New York University found that the Bt toxin remains active in soil for up to 234 days. Also in the United States a study showed that the Bt toxin has toxic effects on the earthworm Lumbricus ”.

Of course, after various considerations, the study calls for rejecting the patenting of seeds, GMOs, and the introduction of transgenic seeds in the country, based on precautionary principles.

RALLT


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