Transgenic+Corn

= Transgenic Corn ​=

toc

General Information
**Patents holders:** AgrEvo, BASF, Bayer, Dow AgroSciences, DuPont, Monsanto Company, Novartis, Pioneer Hi-Bred International, Syngenta Seeds, Zeneca. **Market:** more than 35 million hectares worldwid e
 * Area of Application:** Agriculture

Transgenic corn has been genetically engineered to gain certain agronomic advantages, such as herbicide tolerance and insect resistance. These two traits can also be expressed simultaneously («stacked» gene varieties). (1)

History
Genetic modified (GM) corn was grown for the first time in 1997, in USA and Canada. Since then, GM corn production has expanded to more than 35 million hectares worldwide, including South America, Africa, Asia and Europe, where it was first grown in Spain, in 1998, country that holds now the larger European production of GM corn. Other European countries that grow GM corn are Portugal, Czech Republic and Germany. GM corn is the only commercialized GM crop in EU. (1)

Herbicide Tolerant Corn
 Herbicide tolerance is the most common GM trait in commercial agriculture. Plants that take advantage from it are part of a weed control system that consists of a non-selective herbicide and a corresponding herbicide tolerant crop, which is obtained by genetic engineering. This way, such herbicides can be used to kill weeds without damaging the crops. (1),(2) The method saves labor and cuts soil erosion up to 90 percent.(2) Currently, two of the most used herbicide systems are Roundup Ready (active ingredient: glyphosate), commercialized by Monsanto, and LibertyLink (active ingredient: glufosinate), commercialized by Bayer. (1),(3)

Insect Resistant Corn
The soil bacterium //Bacillus thuringiensis// (//Bt//) expresses several proteins with toxin activity as insecticides for crop pests.(2),(4) Biotechnological agriculture allowed insect resistant crops to be engineered with Bt bacterium genes thus making the once insect food source a killer agent of the same,(4) lessening the use of chemical pesticides (2). The Bt toxins to engineer corn seeds with are selected for their toxicity toward economically significant insects. (4),(5) Only one gene or more («stacked» gene variety) can be used, protecting the corn from both corn-bor­er and corn-rootworm pests.(5) Bt toxins mode of action is still unknown, however, supposedly the toxin ingested by the larvae is activated in its own gut, leading to the formation of pores that release cellular fluids, ending in the larvae mortality.(4) In 1996, the first Bt corn seed was approved by US Environmental Protection Agency (USEPA) as a safe pes­ticide under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). After that, approximately a dozen different Bt corn varieties were registered.(5) Bt corn is commercialized under several different trademarks such as YieldGard by Monsanto, among others.(3)

Nonetheless, a real threat hovers over Bt technology future: insect adaptation to Bt toxins, which has already been assessed. Insect resistance management (IRM) practices are therefore important to avoid such adverse environmental effect that would lead to larger use of higher risk chemical pesticides.(4),(5) In the light of this threat, US Environmental Protection Agency (USEPA) determined several refuge requirements and management practices to Bt corn plantations.(4),(5) In Europe, the European Food Safety Authority (EFSA) has the same responsibility.(6)

Economic and Intangible Benefits
The economic benefits of choosing GM crops are translated in US in savings of $2 billion due to increased yields and reductions in cost production and conventional pesticide use. Furthermore, GM crops have been recognized to improve economies of people in developing countries, which is possible due to the small investing character of such technology, since it is incorporated into the crop seed itself.(2)  Intangible benefits include reduced insecticide use and therefore increased environmental safety, all-in-one product insect control and better pest control. Besides, in the Bt corn case, human safety and labor efficiency are increased since there is no need of handling an insecticide.(7)

Relevant Products
Herbicide Tolerant:
 * ** Product ** || ** Active Ingredient ** |||| ** Company ** ||
 * Roundup Ready || glyphosate |||| Monsanto ||
 * LibertyLink || glufosinate |||| Bayer ||
 * IMI (IR/IT) || imidazolinone |||| BASF ||

Insect Resistant:
 * || **Protect against ** || **Product ** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">**<span style="font-family: 'Calibri','sans-serif';">Bt gene ** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">**<span style="font-family: 'Calibri','sans-serif';">Company ** ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">**Single Bt gene** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Corn borer pests || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">YieldGard Corn Borer || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry 1Ab || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Monsanto ||
 * ^  ||^   || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Herculex I || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry 1F || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Dow Agro Sciences ||
 * ^  || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Corn rootworm pests || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">YieldGard Rootworm || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry 3Bb1 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Monsanto ||
 * ^  ||^   || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Herculex RW || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry34/35Ab1 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Dow Agro Sciences ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">**Stacked Bt gene** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Corn borer and corn rootworm pests || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">YieldGard Plus || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry 1Ab and Cry 3Bb1 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Monsanto ||
 * ^  ||^   || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Herculex Xtra || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Cry 1F and Cry34/35Ab1 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Dow Agro Sciences ||

Both traits:
 * || **<span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Product ** || **<span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Company ** ||
 * <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">**Stacked gene** || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">YieldGard Plus with Roundup Ready Corn 2 || <span style="display: block; font-family: Arial,Helvetica,sans-serif; text-align: center;">Monsanto ||