Risk Assessment Of Transgenic Plants Research Articles

Comparison of overwintering potential of seeds in laboratory and field conditions for the risk assessment of transgenic plants: a sunflower case study

Comparison of overwintering potential of seeds in laboratory and field conditions for the risk assessment of transgenic plants: a sunflower case study

Future challenges in environmental risk assessment of transgenic plants with abiotic stress tolerance

Environmental risk assessment of transgenic plants is a prerequisite to their release into the target environment for commercial use. Risk assessment of the first generation transgenic plants with simple monogenic traits has been carried out with principles and guidelines enlisted in the Cartagena Protocol on Biosafety. For more complex traits such as abiotic stress tolerance, there is a growing need to examine for additional considerations in the risk assessment process based on the different nature of this trait. The salt tolerance-inducingcodA gene is a representative of many abiotic stress tolerance genes that confer salt stress tolerance in transgenic plants. In comparison with simple monogenic Bt trait, the future challenge to environmental release of abiotic stress tolerance genes lies in the question whether these genes such as the salt tolerance-inducing codA will need additional considerations in the risk assessment process?. In the present work, we discussed the nature of abiotic stress tolerance trait, environmental risk assessment issues and comparison of the risk assessment elements on Bt and salt tolerance-inducing codA genes to examine needs for additional considerations in the risk assessment process. We concluded and recommended that the use of abiotic stress tolerance genes such as the salt tolerance-inducing codA gene in transgenic plants does not need additional considerations in risk assessment. Key words: Transgenic plants, abiotic stress tolerance, environmental risk assessment, salt tolerance-inducing codA.

Methods of Risk Assessment of Transgenic Plants. 1. Competition, Establishment and Ecosystem Effects - By Gosta Kjellsson & Vibeke Simonsen

Methods of Risk Assessment of Transgenic Plants. 1. Competition, Establishment and Ecosystem Effects - By Gosta Kjellsson & Vibeke Simonsen

Gene flow hampered by low seed size of hybrids between oilseed rape and five wild relatives

AbstractRecent concern about gene flow from transgenic plants to weedy species has attracted much research on the fitness of their hybrids. However, no studies have been reported on the very early effects of the seed size of hybrids compared with parental plants for germination, seedling establishment and plant growth. We produced hybrids between male sterile Brassica napus L. (oilseed rape) and five weedy relatives, including Brassica juncea (L.) Czern, B. nigra (L.) Koch, B. rapa L., Hirschfeldia incana (L.) Lagrèze-Fossat and Raphanus raphanistrum L. The hybrid seeds formed between B. napus and B. rapa varied in size, while all the hybrid seeds formed with the other species were small. In a direct-seeded field experiment, small seeds of both parents and hybrids had a lower frequency of emergence and a lower seedling survival rate than large seeds, and resulted in later flowering with less biomass. However, no difference was recorded in a transplant experiment, indicating that growth in the juvenile period was sensitive to the small seed class in field conditions only. The optimum environmental conditions in the greenhouse probably homogenized the developmental differences observed at the early stage, and thus reduced the variation during subsequent growth in the field. This point has not been, but should be, considered in risk assessment of transgenic plants. The lower seedling establishment of small-seeded hybrids could hamper further gene flow.

Abstracts of the OECD Workshop on the Biology of Atlantic Salmon (Salmo Salar)

The main purpose of this workshop was to take the first steps in considering whether the general approaches which have been used in the past by the Working Group, primarily to address the safety/ risk assessment of transgenic plants, could be applicable to similar work on the safety/ risk assessment of transgenic fish.The objective of the workshop was to identify and review the kinds of (and availability of) baseline information of (non-transgenic) from traditional fish farming or breeding, and to determine what information might be relevant to risk/ safety assessment; and what information might be needed for the development of a biology document. The overall approach used by the Workshop was similar to that done to first identify and circumscribe the issues about crop species that would inform a risk/safety assessment of the same species after it had been transformed.

Risk Assessment of Transgenic Virus-resistant White Clover: Non-target Plant Community Characterisation and Implications for Field Trial Design

One of the most difficult elements of the ecological risk assessment of transgenic plants is investigation of their potential impact on biodiversity in complex non-target communities. This problem is particularly acute for pasture plants, since many have a track record of invasiveness. In this paper we develop an understanding of some aspects of the ecology of Trifolium repens L. (white clover) in montane vegetation communities in southeastern Australia as part of a larger project investigating potential ecological risks associated with commercial release of newly-developed transgenic virus-resistant T. repens cultivars. We use a combination of floristic surveys and biomass sampling to determine the habitat affinity of T. repens, the structure and composition of associated communities, and the scale at which different abiotic and biotic factors correlate with T. repens abundance. We also compare the abundance of native and exotic species within specific morpho-functional groups and use this to determine the relative significance of T. repens as a community constituent, and to identify native species that would be most at risk by expanding populations of T. repens. We found that T. repens comprises a relatively small component of the total community cover and biomass, but is one of the most abundant herbaceous species in mesic Poa – dominated grasslands and Poa-Eucalyptus woodlands in the study area, and that T. repens abundance is correlated at the within-community scale primarily with soil moisture and fertility. At smaller scales T. repens is limited by the hierarchical dominance of native graminoids and we conclude that competition for inter-tussock space in mesic communities is the most likely mechanism by which expanding populations of T. repens would influence populations of associated native species. These results have significant implications for the manner in which future analysis and risk quantification stages of the risk assessment of virus-resistant T.␣repens and other transgenic pasture plants in complex plant communities are performed.

Assessing the Effects of Bt Maize on the Predatory Mite Neoseiulus cucumeris

The investigation of Neoseiulus cucumeris in the context of the ecological risk assessment of insect resistant transgenic plants is of particular interest as this omnivorous predatory mite species is commercially available and considered important for biological control. In a multitrophic feeding experiment we assessed the impact of Bt maize on the performance of N. cucumeris when offered spider mites (Tetranychus urticae) reared on Bt (Bt11, Syngenta) or non-Bt maize (near isogenic line) and Bt or non-Bt maize pollen as a food source. Various parameters including mortality, development time, oviposition rate were measured. Spider mites were used as a prey for N. cucumeris, since these herbivores are known to contain similar levels of Cry1Ab toxin, when reared on Bt maize, as those found in the transgenic leaf material. In contrast, toxin levels in pollen of this transgenic cultivar are very low. No differences in any of the parameters were found when N. cucumeris was fed with spider mites reared on Bt and non-Bt maize. Pollen was shown to be a less suitable food source for this predator as compared to spider mites. Moreover, subtle effects on female N. cucumeris (9% longer development time and 17% reduced fecundity) were measured when fed with pollen originating from Bt maize as compared to non-Bt maize pollen. Our findings indicate that the predatory mite N. cucumeris is not sensitive to the Cry1Ab toxin as no effects could be detected when offered Bt-containing spider mites, and that the effects found when fed with Bt maize pollen can be assigned to differences in nutritional quality of Bt and non-Bt maize pollen. The significance of these findings is discussed with regard to the ecological relevance for risk assessment of transgenic plants.

Soil microbial community analysis in the environmental risk assessment of transgenic plants

Soil microbial community analysis is one of the most important elements in the environmental risk assessment of transgenic plants. Recent technical advances in this area now enable us to assess the impact of plant genotypes on soil microbial communities with rapid, simple and less biased molecular techniques than the previously used conventional microbiological methodologies. We review the use of these modern molecular techniques from the aspect of environmental assessments of transgenic plants.

Pollen consumption in honey bee larvae: a step forward in the risk assessment of transgenic plants

In order to assess the potential impacts of transgenic plants on larvae of the honey bee, Apis mellifera, information on pollen consumption is needed. We here report on experiments that were conducted with small bee colonies kept in field cages (8 × 14 m) containing only flowering maize plants as protein source. Fully grown worker bee larvae were found to contain between 1720 and 2310 maize pollen grains in their gut before defecation, corresponding to 1.52-2.04 mg of pollen consumed per larva. On average, 74.5% of pollen grains were completely digested while 23.3% were partially digested and 2.2% remained undigested. Our data indicate that the contribution of the protein by directly feeding larvae with pollen is less than 5% in relation to the total amount of protein necessary for complete larval development. We suggest that our measurement for pollen consumption should be taken into account when establishing dose regimes to assess the risk that transgenic plants pose for honey bee larvae. Apis mellifera / pollen consumption / transgenic plant / agrochemical / maize / risk assessment

Viability and longevity of pollen from transgenic and nontransgenic tall fescue (Festuca arundinacea) (Poaceae) plants

Pollen is an important vector of gene flow in plants, particularly for outcrossing species like tall fescue. Several aspects of pollination biology were investigated using pollen from transgenic and nontransgenic plants of tall fescue (Festuca arundinacea Schreb.), the most important forage species worldwide of the Festuca genus. To effectively assess in vitro pollen viability in tall fescue, an optimized germination medium (0.8 mol/L sucrose, 1.28 mmol/L boric acid and 1.27 mmol/L calcium nitrate) was developed. Treatment with relatively high temperatures (36° and 40°C) and high doses of UV-B irradiation (900-1500 μW/cm(2)) reduced pollen viability, while relative humidity did not significantly influence pollen viability. Viability of pollen from transgenic progenies (T1 and T2) was similar to that from seed-derived control plants. Pollen from primary transgenics (T0) and primary regenerants (R0) had various levels of viability. Hand pollination using the primary regenerants and transgenics revealed that no seed set could be obtained when pollen viability was lower than 5%. Pollen from transgenic progenies and nontransgenic control plants could survive up to 22 h under controlled conditions in growth chamber. However, under sunny atmospheric conditions, viability of transgenic and nontransgenic pollen reduced to 5% in 30 min, with a complete loss of viability in 90 min. Under cloudy atmospheric conditions, pollen remained viable up to 240 min, with about 5% viability after 150 min. This report is the first on pollen viability and longevity in transgenic forage grasses and could be useful for risk assessment of transgenic plants.

A sequential approach to risk assessment of transgenic plants expressing protease inhibitors: effects on nontarget herbivorous insects.

Protease inhibitors expressed in transgenic plants can provide enhanced levels of resistance to important pest species. A sequential approach for testing the effects of protease inhibitor-expressing crops on nontarget herbivorous insects has been developed. The approach consists of five tiers. The first two tiers comprise the selection phase. In tier one, field surveys are used to characterise the nontarget invertebrate fauna of a crop. In tier 2, histochemical assays are used to identify the subset of herbivores with a particular class of digestive proteolytic enzymes. In the assessment phase a combination of laboratory 'worst-case scenario' studies (tier 3) and controlled environment or small-scale field trials (tier 4) are used to evaluate the impact of the protease inhibitor-expressing plants on the selected nontarget species. In the final tier, field trials are used to compare the relative effect of transgenic plants and current management practices, such as pesticide use, on selected species. The first four tiers of the approach are described using potatoes expressing cystatins, a family of cysteine proteinase inhibitors, as an example. Although the plants have enhanced levels of resistance to potato cyst nematodes (PCN), Globodera pallida and Globodera rostochiensis, the results establish that they have negligible impact on the nontarget herbivorous insect, Eupteryx aurata.