GM plants

GM also believes that it could eventually close down engine and transmission factories around the world and have a single plant making fuel cells for all of its vehicles. There are 29 types of engines made in 28 GM plants worldwide and 20 transmissions made in 20 worldwide plants. 

There are both ethical and safety concerns about GMOs. Although the developers, and others, are happy that the technology is safe for human health and the environment, others disagree. This is why GM plants and animals are not organically acceptable. 

The study of proteins is especially interesting in food safety because they may act as toxins, antinutrients, or allergens (53). Proteomics, a high-throughput technology able to quantify hundreds of proteins simultaneously, has become very important in comparative studies of GM plants and their nonmodified counterparts (54). Two conceptually different strategies can be followed in comparative proteomics the shotgun and the bottom-up approaches. 

The measures to be taken to ensure co-existence of GM and non GM farming - in order not to exceed the maximum level of GM contamination in food and feed -are by definition rather complex and more or less expensive depending on the respective crop, the relative share of GM plants in the region and specific farming situations. Therefore, for organic producers especially these measures are often perceived as economical threats for the following reasons ... 

Figure 12.3-3. How much benefit would you get trom PMP GM plants ...

In response to public concerns raised by recent monarch butterfly/Bt-corn pollen studies [26, 27], tests are also under way to compare the respective effects of purified lepidopteran-active Bt toxins, of a Bt biopesticide preparation, and of a conventional chemical pesticide commonly used on corn and potentially present when pollen is produced (M.H. Pham-Delegue, unpubhshed data). Such work is expected to assess the biosafety correlates of the different methods used for crop protection, rather than simply comparing the effects of GM plants versus control plants, which is not agronomically realistic. 

Protease inhibitors (Pis) represent a second class of proteins that may be expressed at insecticidal levels in GM plants [e.g. 37, 50-52], although none has been commercialized for this apphcation as yet [53]. Pis can be isolated and purified from many different plants, animals, and microbes. When ingested by insects, some Pis can inhibit their digestive proteolytic enzymes, causing starvation and death [e.g. 54-60]. 

There are as yet few published measurements of PI expression levels in pollen. It is therefore difficult to extrapolate from the results of experiments with purified transgene products to making predictions about the effects of GM plants on bees. However, if we assume that the bees in the bioassays described above received a diet which was 25 percent protein, then the doses of Pis administered ranged from 0.004 to 4 percent of total protein received. GM Pl-plants that are effectively protected from pest attack typically have leaf expression levels ranging from... 

Even if further bioassays and experiments with whole GM plants were to show that avidin may have an impact on bee nutrition, feeding a biotin... 

Herbicide resistance is at present one of the most commonly used traits in commercial cultivars of GM crop plants [1], Since this resistance operates via the production of an enzyme to break down the herbicide and bees lack such substrates, they are extremely unlikely to be harmed by these plants. Bioassays with the purified products of such genes have not been carried out, but some experiments with GM plants have (see Chapter 15). 

With better information on transgene expression levels in pollen and nectar, laboratory assays could be designed to deliver purified proteins at realistic concentrations to bees and thus provide useful information for predicting direct effects of GM plants on adult and larval bees. 

Bioassays with purified proteins provide useful information for broadly determining the areas that require further study. Information obtained may also assist with decisions about how appropriate a particular genetic modification will be for a particular plant species. In the future this methodology could usefully be extended to look at other transgene products under development for expression in GM plants. 

In this chapter, we focus on the effects of whole plants on the behavior of honey bees. We also investigate the risk of direct exposure to the transgene products in the nectar and/or pollen of GM plants, and the possible changes in the secondary metabolism of the plants (nectar quality, floral volatile composition). 

Few experiments have been conducted to assess the behavior of bee populations on GM plants on a large scale, most probably because of the rather drastic regulatory conditions imposed of the production of precommercialized GM plants in the field. However, some observations of bees exposed to transformed plants have been reported. 

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