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Section: Biology
Expert's Opinion on Biosafety

Expert's Opinion on Biosafety

Safety means a lot to each of us. This is a top priority among human values. We are concerned about our life and the health of our children, about the safety of roads and flights, and about the safety of our flats and purses. Generating new technologies, our time generates new fears and new concepts. Having split the atomic nucleus, the humankind turned to the heart of the living cell and deciphered inheritance codes. Biosafety is a new category of man-nature interactions.

Every day we learn about new achievements in biotechnology which can substantially improve our lives. But why does their embodiment take so long? Why is the way from a test-tube to the field and eventually to a supermarket so long?

Biosafety is the lack of actual or predicted undesirable impact on the modified organism (as compared to the initial unmodified organism) on the environment (The Decree of the Russian Federation Government dated 16 February, 2001 No.120 “On State Registration of Genetically Modified Organisms”)

This time is needed to make sure that a new product brings no harm to human health and the environment. A final decision on the use of a product is made by government authorities: the process is regulated by the appropriate national legislation and international documents.

Speaking about the products of modern biotechnology in agriculture, we usually mean genetically modified organisms (GMO) as such, the products of their vital activity or treatment. The term biosafety is applied to living GM-products that interact with the environment, the terms food safety or forage safety are used for the products of their processing.

“Genetically modified products are treated using much stricter requirements than the varieties obtained in regular selection and even the selection in which mutations are due to radiation and treatment by chemicals”
“… society should clearly realize that no ‘zero biological risk’ exists in nature, the concept of the risk …
is a trick aimed at hindering the development of this trend in research and technology”
Norman Borlaug*
First, it is noteworthy that the system of biosafety in the Russian Federation is based on the principles elaborated by the world community: 1) scientific estimate of the use of GMO and 2) independence of scientific expertise as applied to each case of a release of a GMO into the environment. On this basis, the Russian scientific community developed “Technical Guide to the Estimate of Biosafety of Genetically Modified Plants” in 2001. The Guide was approved by the Expert Committee for Biosafety Issues at the RF Ministry of Industry, Science and Technology and the Interdepartmental Commission for Genetic Engineering Problems.

The most important stage in testing the biosafety of genetically modified plants is field tests. In the Russian Federation, such tests can be carried out only on appropriate lands, which as a rule are located within the territories of specialized research institutes in different agroclimatic zones. The experts of the Interdepartmental Commission developed Regulations for the Registration and Inspection of the Test Grounds for Controlled Production of Genetically Modified Products. Testing GM-plants following the regulations precludes their unauthorized distribution beyond the limits of agricultural farms.

Let us consider how the risks of release of genetically modified plants into the environment are identified by the example of biosafety studies of genetically modified soybean in which the author was involved.

Soy, the Queen of Fields

The subject of inquiry is genetically modified soybean GTS 40-3-2 (Stine 2254 RR — Monsanto Company) resistant to herbicide glyphosate. The soybean was obtained as a result of inserting the soil bacterium Agrobacterium tumefaciens into the plant genome of the gene that codes the synthetase enzyme (EPSPS).

Genetically modified glyphosate -resistant soybean has become one of the most popular of transgenic plants. Its use at weedy fields not only secures an increase in the crop (up to 40 %!), but also reduces the quantity of applied herbicide, the expenditures for soil cultivation and water losses, which results in more profitable environment-friendly farming. Last year the soybean resistant to herbicides still dominated among transgenic agricultural crops in the eight countries: USA, Argentina, Brazil, Canada, Mexico, Romania, Uruguay, and South Africa.

The general concept of biosafety tests of genetically modified plants suggests special examination of the genetic structure of the populations of wild ancestors of transgenic plants in their speciation centers and their ability to breed with wild congeners. In our case, this suggests the study of the wild soy growing in the Russian Federation, which was carried out by the scientists from the “Bioinzheneriya” Center (Moscow), Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk), the Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok), the Soybean Institute of the Far-Eastern Branch of the Russian Academy of Agricultural Sciences (Blagoveshchensk), and Novosibirsk State Pedagogical Institute.

The Far East is one of the main regions in our country where the soybean Glycine max is cultured. At the same time there is wild soy Glycine soja. What potential risks does planting the transgenic herbicide-resistant soybean bring to the natural population in the region?

To answer this question the scientists have to determine if the wild soy is a weed or if it can turn into a weed in the future if it becomes resistant to the herbicide. They had to prepare geobotanical descriptions and estimate the genetic structure of the population of the wild soy. To ensure an exact prediction they had to estimate the potentialities of natural cross-pollination between wild and cultivated species. Thus, they had to carry out special experiments on interspecific breeding with exact identification of resulting interspecies hybrids. As soon as the problem is stated, it is time to start looking for wild soy in the fields…

Looking for wild soy

Wild Ussuri soybean is considered a progenitor or at least the closest relative of the cultivated soybean. In Russia, it grows only in the south of the Far East, the genetic center of the origin of the species. The only area of its distribution encompasses the south-east part of the Amur region, the southern part of the Khabarovsk Territory and almost the whole Primorsky Territory. The most part of findings of wild soy was recorded near Lake Khanka, in the regions bordering China.

“Fear <...> of biotechnology products in the public is to a great extent caused by the inability of our educational institutions to implant elementary agricultural knowledge in pupils”
Norman Borlaug

The areas covered by cultivated soybean in the Russian Far East are within the areal of natural distribution of its wild relative. Since both species are typical self-fertilizers, the occurrence of interspecific hybrids in natural conditions is very unlikely, since even free cross-pollination between the plants of cultivated soybean is usually less than one per cent.

The “Bioinzheneriya” Center and the Institute of Cytology and Genetics together with the Pacific Institute

of Bioorganic Chemistry and the Soybean Institute organized expeditions in 1998—2000 to collect the specimens of wild soy in the growing areal – the Amur Region and the Primorsky Territory. During this period the scientists described the plant communities and collected soybean seeds in more than 200 sites. The seed specimens were delivered to the Gene Bank of the All-Russia Institute of Plant Cultivation for further examination.

The greatest genetic distance from the main population of wild soy was demonstrated by separate groups that were in genetic isolation. But while some specimens from the Gamov Peninsula (Primorsky Territory) demonstrated high genetic variability, the population of the Amur Region on the contrary was genetically uniform. Earlier, Japanese and Chinese scientists revealed the relation between the genome features and geographical distribution of wild soy populations and found the hypothetical center of the origin and ‘domestication’ of ancient Chinese soybean varieties. It is assumed that it was one of Chinese provinces in the valley of the Yangtze River. Probably, the relative genetic monotony of the Far-Eastern population of wild soy is a result of its geographic remoteness from the center of origin of the species.

Geobotanical studies proved that wild soy behaves as anthropophilic ruderal weed, which in everyday language means that it grows near buildings, in free spaces, but not in fields. In farm lands – in particular used for cultivated crops – wild soy occurs seldom. This is determined by its biological features: long vegetative period, low seed productivity, lack of adaptation to long-distance spreading of seeds, etc.

Analysis of 280 plants of wild soy from different parts of the area supported the idea on the stable number of chromosomes within natural groups. For all samples the double set of chromosomes was 2n=40, which

is typical of wild soy and was supported by the expedition materials. Molecular analysis of the samples showed that the level of polymorphism (variability) in wild soy plants is much higher than in cultivated plants.

No hybrids

To crossbreed two soybean species experiments were run on free pollination at experimental grounds of the All-Russia Research Institute of Biological Protection of Plants of the Russian Academy of Agricultural Sciences (Krasnodar) and on artificial cross-pollination in greenhouses (Institute of Cytology and Genetics, Novosibirsk).

Using the genetically modified soybean as a pollen donor in natural conditions did not yield interspecific hybrids with wild soy. Under artificial cross-pollination of wild (maternal plants) and cultivated (paternal plants) soybean species 54 cross-combinations were tried. However, the experiment resulted in only two (!) seeds, one of which was nonviable.

“Today I am convinced that already now the humankind has proper technologies available <…> that can surely feed ten billion people. The point is only if the food producers worldwide will get an access to these technologies”
Norman Borlaug

The hybrid nature of the single plant was confirmed in molecular analysis. In parallel with the polymerase chain reaction the hybrid plant genome was analyzed for the presence of the genetic structure ensuring the resistance to the herbicide in transgenic plants of cultivated soy. As a result, such a genetic structure was found in the first hybrid plant (generation F1), but was absent in its progeny (plants F2 and F3). Most probably without the pressure of the natural selection the transgenic insertion is eliminated rather rapidly, i.e. disappears from the genome. A similar phenomenon was earlier noted for interspecific hybrids of genetically modified oilseed rape and its relative – wild radish.

Thus, one can unambiguously conclude that under the cross-pollination of cultivated soybean with transgenic plants the efficiency of hybridization is extremely low. In this case, the genetic construction that causes resistance to the herbicide vanishes rather fast under natural conditions. However, the studies on the biosafety of transgenic soybean have not been ceased. In the Far East, the natural potential ability to hybridization in cultivated and wild species is being studied.

Researchers of the “Bioinzheneriya” Center and the Far-Eastern Research Institute of Biological Protection of Plants have been thoroughly examining the populations of wild soy for two field seasons nearby Khanka Lake, as well as along the borders of agricultural fields with cultivated soy. Of particular interest are the populations growing near the fields where no crop rotation of cultivated soybean has been performed over several years. However, the scientists have not yet found interspecific hybrids on the basis of morphological features, which evidences the stability of the wild soy populations neighboring agricultural populations.

Of course, the work done is only a part of biosafety checks that are obligatory for a transgenic organism to be officially registered. However, it has speeded up the process that should result in the ‘legal’ introduction of transgenic soy and enable Russian producers to get on-practice acquaintance with the advantages promised by modern biotechnologies.

*Norman Borlaug, Nobel Prize winner, the father of “Green Revolution” (cited from Ekologiya i Zhizn, No 4, 2001)

References

Dymina G. D., Gorovoj P. G., Deineko E. V., Seitova A. M., Ignatov A. N., Suprunova T. P., Serjapin A. A., Ala A. Ja., Dorokhov D. B., Shumny V. K., Skryabin K. G. Genetic Polymorphism in Wild Soybean Population of Russian Far East, collection and primary characterization of collection. In: International Conference “Genetic Collections, Isogenic and Alloplasmic Lines - 2001”. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, p. 146-148.

Seitova A. M., Ignatov A. N., Suprunova T. P., Tsvetkov I. L., Deineko E. V., Dorokhov D. B., Skryabin K. G. Study of soybean (Glycine soja Sieb. & Zucc.) in Far East region of Russia. Genetic diversity of wild soy. In: Rus. J. of Genetics, vol. 40, No. 2, 2004, p. 165-171.

Dorokhov D. B., Ignatov A. N., Deineko E. V., Serjapin A. A., Ala A. Ja., Skryabin K. G. The chance for gene flow from herbicide-resistant GM soybean to wild soy in its natural inhabitation at Russian Far East region. In: Introgression from Genetically Modified Plants into Wild Relatives, Edited H.C.M. den Nijs et al., CABI Publishing 2004, p. 151-161.

The research is supported by Russian Foundation for Basic Reseach No. 03-04-48997a

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