GM<\/a> crops that are resistant to herbicides:<\/strong><\/span><\/h4>\nUsage of herbicides in modern agriculture is an effective means of eliminating weeds from cultivated crops. By inactivating target proteins (usually enzymes) important for essential functions such as photosynthesis & other biosynthetic pathways, herbicides exert their action. Herbicides are also non-selective, which restricts their use because crops & weeds have common pathways. Herbicide selectivity can be accomplished by producing particular herbicide-tolerant plants to ensure the protection of crops from the herbicide applied.<\/span><\/p>\nIn plants, there are two methods for engineering herbicide resistance.<\/span><\/p>\n(a)Modification of the target herbicide action enzymes to make them insensitive to the herbicide.<\/span><\/p>\nOr<\/span><\/p>\nIn order to allow normal metabolism despite the presence of herbicide, overexpression of the target protein.<\/span><\/p>\n(b) Etoxifying the herbicide by adding the gene that degrades the herbicide prior to its action in plants.<\/span><\/p>\nResistance obtained by the first mechanism has been developed for the herbicide:<\/strong><\/span><\/h4>\n— glyphosate<\/span><\/p>\n— Atrazine and<\/span><\/p>\n— sulfonylureh.<\/span><\/p>\nIn the second strategy resistance has been obtained against:<\/span><\/p>\n— bromoxynil<\/span><\/p>\n— phosphinothrycine.<\/span><\/p>\n— 2.4 D<\/span><\/p>\nHistory to Technology <\/strong><\/span><\/h4>\nHow are these herbicides functioning? <\/strong><\/span><\/h4>\nThese herbicides target key enzymes in the plant’s metabolic pathway that disrupt the production of plant food and ultimately kill it. And how do the plants evoke tolerance for herbicides? Some may have acquired the trait through selection or mutation: or more recently, plants may be modified through genetic modification.<\/span><\/p>\n <\/p>\n
Why the growth of HT crops <\/strong><\/span><\/h4>\nWhat is new is the ability to generate a degree of tolerance for large herbicides that regulate most other green plants, in particular glyphosate & glufosinate. Having two herbicides is beneficial for the management of weeds and has limited direct effects on animal life and is not persistent. They are extremely powerful & among the best to use agrochemicals. They are, sadly, equally successful against crop plants.<\/span><\/p>\nTolerant crops 1.Glyphosate- <\/strong><\/span><\/h4>\nBy blocking the enzyme EPSPS (5-) and the enzyme involved in the biosynthesis of aromatic amino acids , vitamins & several secondary plant metabolites, glyph sate herbicides destroy plants. There are several methods by which crops can be adjusted to be tolerant of glyphosate. One solution is to add a soil bacterium gene that generates an EPSPS resistant glyphosate. Another approach is to add a separate gene from the soil bacterium that creates a degrading enzyme for glyphosate.<\/span><\/p>\nTolerant crops 2.Glufosinate- <\/strong><\/span><\/h4>\nGlufosinate herbicides contain phosphinothricin, the active ingredient that destroys plants by blocking the enzyme responsible for the synthesis of nitrogen and detoxifying ammonia as a result of plant metabolism. Tolerant glufosinate-modified crops contain a bacterial gene that produces an enzyme that detoxifies phosphorus and prevents it from causing damage. Other techniques that genetically alter crops to withstand exposure to herbicides including:\u00a0\u00a0\u00a0<\/span><\/p>\n1.Producing a new herbicide detoxifying protein:<\/span><\/p>\n2.Modifying the target protein of the herbicide so that the herbicide will not affect it. Or<\/span><\/p>\n3.Producing physical or physiological obstacles that prohibit the herbicide from entering the plant. The first two methods are the most common ways in which researchers grow herbicide-tolerant crops.<\/span><\/p>\nAdvantages of Resistant Herbicide Crops <\/strong><\/span><\/h4>\n\u2014Excellent management of weeds & therefore greater crop yields;<\/span><\/p>\n\u2014Flexibility to manage weeds later in the growth of the plant;-<\/span><\/p>\n\u2014Reduced spray numbers throughout the season;<\/span><\/p>\n\u2014Reduced use of fuel (due to less spraying);<\/span><\/p>\n\u2014Reduced compaction of the soil (because of less need for spraying on the land);<\/span><\/p>\n\u2014Use of compounds of low toxicity which do not remain active in the soil &;<\/span><\/p>\n\u2014The opportunity to use no-till or conservation \u2013 till scheme, with consequent benefits to soil structure & organisms;<\/span><\/p>\nSafety Aspects of Herbicide Tolerance Technology<\/strong><\/span><\/h4>\nTown of Toxicity & Allergens: <\/strong><\/span><\/h4>\nGovernment regulatory agencies in many nations have ruled that, relative to their non-GM counterparts, crops with herbicide-tolerant conferring proteins do not face any other environmental & health risks. In compliance with the guidelines established by relevant international organizations, added proteins are evaluated for possible toxic & allergenic activity. They are not recognized toxins or allergens from source with no history of allergen city or toxicity: & they have roles, with are well understood.<\/span><\/p>\nImpact on crops:<\/strong><\/span><\/h4>\nIn contrast to parental crops, the expression of these proteins does not harm the growth of the plant or result in poorer agronomic results. No other metabolic modifications occur in the plant, except for the expression of an additional enzyme for herbicide tolerance or the modification of an already developed enzyme. Crop persistence or invasiveness<\/span><\/p>\nA significant environmental problem for herbicide-tolerant crops is their ability to produce new weeds by crossing with wild relatives or merely persisting in the wild. However, this capacity is evaluated prior to implementation & is also tracked after planting the crop. The latest scientific evidence shows that in the absence of herbicide application, GM herbicide-tolerant crops are no more likely than their non-GM counterparts to be invasive in agricultural fields or in natural habitats. There is no evidence of improved persistence in herbicide-resistant crops currently on the market.<\/span><\/p>\nProblems with crops resistant to herbicides <\/strong><\/span><\/h4>\n\nTo grow such types of GM(Genetically Modified) crops, you need a lot of chemical substances.<\/span><\/li>\nNo other metabolic modifications occur in the plate, except for the expression of an additional enzyme for herbicide tolerance or modification of an already existing enzyme.<\/span><\/li>\nA major environmental problem associated with herbicide-tolerant crops is their ability to produce new weeds by erosing wild relatives or simply persisting in the wild,<\/span><\/li>\nBy crossing, the herbicide resistance gene can be passed into the weed from the crops. In such a situation, the weed can become tolerant of herbicides.<\/span><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"Transgenic Pants Transgenic Plants Application. Conventionally, hybridization, mutagenesis & polyploidy produce the genetic variation required for crop improvement. More recently, biotechnological methods, called variation, have become available for some genetic variations. In vitro plant cell culture produces a large amount of genetic variation, known as somaclonal variation, from which a variety of useful variants have […]<\/p>\n","protected":false},"author":2,"featured_media":607,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[98],"tags":[188,264],"yoast_head":"\n
Transgenic Plants Application - Agribusiness Education and Research International<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n \n \n\t \n\t \n\t \n