{"id":317,"date":"2024-03-23T10:07:32","date_gmt":"2024-03-23T10:07:32","guid":{"rendered":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/?post_type=chapter&#038;p=317"},"modified":"2024-11-20T12:15:43","modified_gmt":"2024-11-20T12:15:43","slug":"8-2-transgenic-plants","status":"publish","type":"chapter","link":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/chapter\/8-2-transgenic-plants\/","title":{"raw":"8.2 Transgenic plants","rendered":"8.2 Transgenic plants"},"content":{"raw":"Transgenic plants are genetically modified organisms (GMOs).\u00a0 These plants carry foreign genes introduced through genetic engineering. These plants\u00a0 can take up desirable traits such as pest resistance, enhanced nutrition, and tolerance to environmental stress and thus have revolutionized agriculture, medicine, and environmental science.Bt cotton, Bt corn, Bt potato, and Bt tobacco are a few types of transgenic plants. Endotoxin, which is present in these genetically modified plants, inhibits the activity of a variety of pests that are members of the order Lepidoptera, Coleoptera, Hymenoptera, Diptera, and Nematoda.\r\n<h3><strong>Development of Transgenic Plants<\/strong><\/h3>\r\nGenetic engineering techniques are used to create transgenic plants. These plants are produced by inserting foreign genes into a plant's genome.These genes provide the plant additional features or attributes, such enhanced nutritional value or resistance to pests, herbicides, or environmental stressors.\r\n\r\nThe following steps are typically included in the process\r\n<ol>\r\n \t<li><strong>Gene Identification and Isolation<\/strong>:\r\n<ul>\r\n \t<li>The first step involves the identification of\u00a0 the gene of interest from another organism that confers a desirable trait (e.g., pest resistance or drought tolerance).<\/li>\r\n \t<li>The donor organism\u2014such as a bacteria, mammal, or other plant\u2014has the desired gene has to be identified<\/li>\r\n \t<li>This gene is then isolated using molecular biology techniques.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Gene Cloning<\/strong>:\r\n<ul>\r\n \t<li>The isolated gene is then cloned using vectors such as plasmids or viral genomes.<\/li>\r\n \t<li>This is done by inserting the desired gene\u00a0 into a suitable vector (a carrier DNA molecule, such as a plasmid or a virus).<\/li>\r\n \t<li>To make sure the gene works correctly in the target plant, a promoter sequence\u2014which regulates gene expression\u2014is attached to it.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Gene Insertion into Plant Cells<\/strong>:\r\n<ul>\r\n \t<li>The next steps involves the introduction of\u00a0 the transgene\u00a0 into plant cells .<\/li>\r\n \t<li>This is done by using methods such as:<\/li>\r\n \t<li><strong>Agrobacterium-mediated transformation:<\/strong> The gene is inserted into the plant genome by use of Agrobacterium tumefaciens, a naturally occurring soil bacterium.\r\n<strong>Gene gun (Biolistics):<\/strong> tiny particles coated in DNA are injected into plant cells.\r\n<strong>Electroporation:<\/strong> The process of making holes in the cell membrane for DNA entrance using electric pulses.\r\n<strong>Microinjection :<\/strong> This is direct injection of DNA into the nucleus of plant cells .<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Selection and Regeneration<\/strong>:\r\n<ul>\r\n \t<li>Selectable indicators, such as resistance to antibiotics or herbicides, are used to identify plant cells that have successfully incorporated the transgene.<\/li>\r\n \t<li>Using tissue culture techniques, the transformed cells are cultivated in hormone-rich, nutrient-rich conditions to grow back into complete plants.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Screening and Verification<\/strong>:\r\n<ul>\r\n \t<li>Transgenic plants are examined using methods such as PCR, Southern blotting, or protein assays to verify the introduced gene's existence, expression, and stability.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<strong>6. Commercialization and Field Testing :\u00a0<\/strong>\r\n<ul>\r\n \t<li style=\"list-style-type: none\">\r\n<ul>\r\n \t<li>The performance of the transgenic plants is evaluated in the field. Prior to commercial cultivation, regulatory approval is sought to guarantee safety.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>Agrobacterium-mediated plant transformation<\/h2>\r\nOne popular technique for transferring foreign genes into plants is agrobacterium-mediated gene transfer. This method takes advantage of the soil bacterium <em>Agrobacterium tumefaciens<\/em>' innate capacity to introduce DNA into plant cells. <strong>Crown gall disease<\/strong> in plants is caused by the bacterium Agrobacterium tumefaciens.\r\nIt causes tumors by transferring a portion of its DNA, known as T-DNA, from the Ti (tumor-inducing) plasmid into the plant genome.\r\n<h3>Ti Plasmid<\/h3>\r\nThe size of the Ti plasmid is considerable, usually between 200 and 800 kilobases.T-DNA (Transfer DNA) Region which is between 10 and 30 kilobases long, gets incorporated into the plant's DNA during infection.\r\n\r\nThe Ti plasmid contains the following genes \/regions\r\n\r\n<strong>T-DNA<\/strong>\u00a0 : this region contains genes responsible for <strong style=\"font-size: 1em\">Tumor formation:<\/strong><span style=\"font-size: 1em\"> These genes cause unchecked cell division, which results in the creation of a crown gall and tumor and <\/span><strong style=\"font-size: 1em\">Opine synthesis:<\/strong><span style=\"font-size: 1em\"> The bacterium uses the opines produced by the enzymes encoded by these genes as a source of nutrition.<\/span>\r\n\r\n<strong>Border Sequences : <\/strong>The left border (LB) and right border (RB) are two brief (about 25 base pairs) direct repeat sequences that flank the T-DNA. The removal and integration of T-DNA into the plant genome depend on these sequences.\r\n\r\n<strong>Vir (Virulence) Region :<\/strong> This area, which lies outside the T-DNA, is home to genes that facilitate the transfer process. Proteins that excise the T-DNA are encoded by the Vir genes. These Deliver the T-DNA to the nucleus of the plant cell and aid in its incorporation in the plant's genome.\r\n\r\n<strong>Origin of Replication : <\/strong>permits independent replication of the Ti plasmid in the Agrobacterium.\r\n\r\n<strong>Opine Catabolism Genes :<\/strong>Opines, which are formed by infected plant cells, can be used by Agrobacterium as a source of carbon and nitrogen\r\n<h4>Steps involved in Agrobacterium mediated gene transfer in plants<\/h4>\r\nThe following crucial steps are involved in the process:\r\n\r\n<strong>Engineering the Ti Plasmid ( disarmed Ti plasmids ):\u00a0 <\/strong>To stop tumor formation, the T-DNA's tumor-inducing genes are eliminated. The desired gene and a selectable marker gene (such as tolerance to antibiotics or herbicides) are added to the T-DNA region.\r\n\r\n<strong> Preparation of the Vector :<\/strong> A non-tumorigenic, disarmed form of the bacteria is employed.The modified Ti plasmid carrying the desired gene is introduced into Agrobacterium tumefaciens.\r\n\r\n<strong> Preparing Plant Cells : <\/strong>In order to expose cells for infection, plant tissues or explants (such as leaf discs) are injured. Agrobacterium infection susceptibility is increased by wounding.\r\n\r\n<strong>Co-Cultivation :<\/strong> The explants are incubated with Agrobacterium tumefaciens.The T-DNA containing the desired gene is then transferred by the\u00a0 bacterium into the plant cell\u2019s genome through the following steps:\r\n<ul>\r\n \t<li style=\"list-style-type: none\">\r\n<ul>\r\n \t<li><strong>Attachment<\/strong>: Agrobacterium attaches to the plant cell wall.<\/li>\r\n \t<li><strong>T-DNA Transfer:<\/strong> T-DNA is excised from the plasmid and transported into the plant cell nucleus . The bacterium\u2019s Vir (virulence) proteins mediates this transport.<\/li>\r\n \t<li><strong>Integration:<\/strong> The T-DNA then integrates randomly into the plant\u2019s chromosomal DNA.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<strong> Selection and Regeneration : <\/strong><span style=\"font-size: 1em\">A selectable marker, such as resistance to antibiotics or herbicides, is used to identify plant cells that have the transgene. <\/span><span style=\"font-size: 1em\">To grow into whole plants, the chosen cells are cultivated in a nutritional medium with plant hormones.<\/span>\r\n\r\n<strong> Confirmation of Transformation : <\/strong>Successful integration and expression of the transgene are verified by molecular methods (such as Southern blot, PCR, or reporter genes like GUS).\r\n\r\n<img src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/ae\/Transfection_by_Agrobacterium.svg\/700px-Transfection_by_Agrobacterium.svg.png?20081031132512\" alt=\"File:Transfection by Agrobacterium.svg\" width=\"491\" height=\"421\" class=\"aligncenter\" \/>\r\n<pre>A.Agrobacterium cell, B. <span style=\"font-size: 1em\">Agrobacterium DNA, C. T<\/span><span style=\"font-size: 1em\">i Plasmid<\/span><\/pre>\r\n<div>\r\n<pre>a.T-DNA ; b.vir genes ; c.replication origin; d.opines catabolism\r\n\r\nD. Plant cell ; E.\u00a0Plant mitochondria ; F.Plant chloroplast ; G.Plant nucleus<\/pre>\r\n<ol>\r\n \t<li>\r\n<pre>VirA recognition<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>VirA phosphorylates VirG<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>VirG causes transcription of Vir genes<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>Vir genes cut out T-DNA and form nucleoprotein complex (\"T-complex\")<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>T-complex enters plant cytoplasm through T-pilus<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>T-DNA enters into plant nucleus through nuclear pore<\/pre>\r\n<\/li>\r\n \t<li>\r\n<pre>T-DNA achieves integration<\/pre>\r\n<\/li>\r\n<\/ol>\r\n<p style=\"text-align: center\"><a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Transfection_by_Agrobacterium.svg\" target=\"_blank\" rel=\"noopener\">\"Transfection by Agrobacterium\"<\/a><span>\u00a0by\u00a0<\/span><a>Chandres<\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\" target=\"_blank\" rel=\"noopener\">CC BY-SA 3.0<\/a><\/p>\r\n<img src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/6f\/Mango_%28Mangifera_indica%29_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_%2832589809932%29.jpg\/800px-Mango_%28Mangifera_indica%29_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_%2832589809932%29.jpg?20211120221215\" alt=\"File:Mango (Mangifera indica) Probably crown gall caused by Agrobacterium tumefaciens (32589809932).jpg\" class=\"aligncenter\" width=\"572\" height=\"429\" \/>\r\n<p style=\"text-align: center\"><a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mango_(Mangifera_indica)_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_(32589809932).jpg\" target=\"_blank\" rel=\"noopener\">\"Mango (Mangifera indica) Probably crown gall caused by Agrobacterium tumefaciens\"<\/a><span>\u00a0by\u00a0<\/span><a>Scot Nelson Via Wikimedia commons<\/a><a><\/a><a><\/a><span>\u00a0is in the\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\" target=\"_blank\" rel=\"noopener\">Public Domain, CC0<\/a><\/p>\r\n\r\n<h1>Applications of transgenic plants<\/h1>\r\n<h2>Agricultural Applications<\/h2>\r\n<strong>Production of Pest and Disease Resistance crops\u00a0<\/strong>\r\n\r\nFor instance, genes from the bacteria Bacillus thuringiensis are present in Bt crops (such as Bt cotton and Bt maize), which reduce the need for pesticides by creating a protein that is harmful to particular pests.\r\nCrop losses are reduced by plants that have been genetically modified to be resistant to bacterial, viral, or fungal diseases.\r\n\r\n<strong>Resistance to Herbicides<\/strong>\r\nCertain pesticides are tolerated by transgenic plants, enabling effective weed management without endangering crops.\r\nFor instance, roundup Glyphosate tolerance in ready soybeans makes controlling weeds easier.\r\n\r\n<strong>Stress Tolerance<\/strong>\r\n\r\nAbiotic stressors such as drought, salt, high temperatures, and unfavorable soil conditions are things that plants are designed to survive.\r\nFor instance, rice cultivars that can withstand salt on saline soils.\r\n\r\n<strong>Increased Production and Development<\/strong>\r\nIncreased productivity results from genetic alterations that enhance growth rates, nutrient intake, and photosynthetic efficiency.\r\n<h2>Nutritional Improvements<\/h2>\r\n<strong>Biofortification<\/strong>\r\n\r\nIn order to combat malnutrition, transgenic plants are created to increase the nutritional value of food.\r\n\r\nFor instance, provitamin A (beta-carotene)-enriched golden rice helps people who are vitamin A deficient.\r\n\r\n<strong>Improved Quality<\/strong>\r\n\r\nFeatures like improved shelf life, taste, or texture are added. For instance, Flavr Savr tomatoes have a longer shelf life since they don't rot.\r\n<h2>Applications in Medicine and Pharmacy<\/h2>\r\n<strong>Manufacturing Biopharmaceuticals<\/strong>\r\nPlants serve as biofactories that produce medicinal proteins, antibodies, and vaccines. For instance, tobacco plants were modified to yield the ZMapp medication, which is used to treat Ebola.\r\n<strong>\u00a0Edible Vaccines <\/strong>\r\n\r\nAntigens produced by transgenic plants boost immunity when ingested. Hepatitis B vaccination antigen-expressing potatoes are an example.\r\n\r\n<strong>\u00a0Reduction of Allergens<\/strong>\r\nIt is possible to reduce or completely eradicate allergenic substances in crops such as wheat and peanuts.\r\n\r\n<\/div>\r\n<h2>Industrial Applications<\/h2>\r\n<strong>Biofuel Production<\/strong>\r\nTransgenic plants with altered lignin or increased cellulose content increase biomass for the manufacture of biofuel.\r\nFor instance, switchgrass that has been genetically modified to produce ethanol.\r\n\r\n<strong>Bioplastics<\/strong>\r\nBiodegradable plastics are made from modified plants.\r\nTransgenic corn that produces polyhydroxyalkanoates (PHAs) is one example.\r\n\r\n<strong>Phytoremediation<\/strong>\r\nToxins, hydrocarbons, and heavy metals are among the contaminants that are cleaned up by transgenic plants.\r\nFor instance, plants designed to take up mercury or arsenic from polluted soil.\r\n<h2>Environmental\u00a0 Applications<\/h2>\r\n<strong>Decreased Use of Chemicals<\/strong>\r\nCrops that are resistant to pests and herbicides reduce the need for chemical pesticides and herbicides, which in turn lessens pollution in the environment.\r\n\r\n<strong>\u00a0Sequestration of Carbon<\/strong>\r\nClimate change can be lessened by producing plants that have improved carbon fixation.\r\n\r\n&nbsp;\r\n<h3><strong>Examples of Transgenic Crops and Their Traits<\/strong><\/h3>\r\n<table style=\"width: 849px;height: 214px\">\r\n<thead>\r\n<tr>\r\n<th style=\"width: 276.625px\"><strong>Crop<\/strong><\/th>\r\n<th style=\"width: 320.92px\"><strong>Trait<\/strong><\/th>\r\n<th style=\"width: 209.682px\"><strong>Purpose<\/strong><\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 276.989px\">Bt cotton<\/td>\r\n<td style=\"width: 321.648px\">Insect resistance<\/td>\r\n<td style=\"width: 210.045px\">minimizes damage from pests<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 276.989px\">Golden rice<\/td>\r\n<td style=\"width: 321.648px\">Vitamin A enrichment<\/td>\r\n<td style=\"width: 210.045px\">Prevents malnutrition<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 276.989px\">Herbicide-tolerant soybean<\/td>\r\n<td style=\"width: 321.648px;text-align: left\">Herbicide resistance<\/td>\r\n<td style=\"width: 210.045px\">Makes weed control easier<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 276.989px\">Virus-resistant papaya<\/td>\r\n<td style=\"width: 321.648px\">Resistance to Papaya Ring Spot Virus<\/td>\r\n<td style=\"width: 210.045px\">Prevents viral diseases<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 276.989px\">Arctic apple<\/td>\r\n<td style=\"width: 321.648px\">Non-browning<\/td>\r\n<td style=\"width: 210.045px\">enhanced appearance and shelf life<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h3>Test Your Understanding<\/h3>\r\n<span>[h5p id=\"116\"]<\/span>\r\n\r\n<span>[h5p id=\"117\"]<\/span>","rendered":"<p>Transgenic plants are genetically modified organisms (GMOs).\u00a0 These plants carry foreign genes introduced through genetic engineering. These plants\u00a0 can take up desirable traits such as pest resistance, enhanced nutrition, and tolerance to environmental stress and thus have revolutionized agriculture, medicine, and environmental science.Bt cotton, Bt corn, Bt potato, and Bt tobacco are a few types of transgenic plants. Endotoxin, which is present in these genetically modified plants, inhibits the activity of a variety of pests that are members of the order Lepidoptera, Coleoptera, Hymenoptera, Diptera, and Nematoda.<\/p>\n<h3><strong>Development of Transgenic Plants<\/strong><\/h3>\n<p>Genetic engineering techniques are used to create transgenic plants. These plants are produced by inserting foreign genes into a plant&#8217;s genome.These genes provide the plant additional features or attributes, such enhanced nutritional value or resistance to pests, herbicides, or environmental stressors.<\/p>\n<p>The following steps are typically included in the process<\/p>\n<ol>\n<li><strong>Gene Identification and Isolation<\/strong>:\n<ul>\n<li>The first step involves the identification of\u00a0 the gene of interest from another organism that confers a desirable trait (e.g., pest resistance or drought tolerance).<\/li>\n<li>The donor organism\u2014such as a bacteria, mammal, or other plant\u2014has the desired gene has to be identified<\/li>\n<li>This gene is then isolated using molecular biology techniques.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Gene Cloning<\/strong>:\n<ul>\n<li>The isolated gene is then cloned using vectors such as plasmids or viral genomes.<\/li>\n<li>This is done by inserting the desired gene\u00a0 into a suitable vector (a carrier DNA molecule, such as a plasmid or a virus).<\/li>\n<li>To make sure the gene works correctly in the target plant, a promoter sequence\u2014which regulates gene expression\u2014is attached to it.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Gene Insertion into Plant Cells<\/strong>:\n<ul>\n<li>The next steps involves the introduction of\u00a0 the transgene\u00a0 into plant cells .<\/li>\n<li>This is done by using methods such as:<\/li>\n<li><strong>Agrobacterium-mediated transformation:<\/strong> The gene is inserted into the plant genome by use of Agrobacterium tumefaciens, a naturally occurring soil bacterium.<br \/>\n<strong>Gene gun (Biolistics):<\/strong> tiny particles coated in DNA are injected into plant cells.<br \/>\n<strong>Electroporation:<\/strong> The process of making holes in the cell membrane for DNA entrance using electric pulses.<br \/>\n<strong>Microinjection :<\/strong> This is direct injection of DNA into the nucleus of plant cells .<\/li>\n<\/ul>\n<\/li>\n<li><strong>Selection and Regeneration<\/strong>:\n<ul>\n<li>Selectable indicators, such as resistance to antibiotics or herbicides, are used to identify plant cells that have successfully incorporated the transgene.<\/li>\n<li>Using tissue culture techniques, the transformed cells are cultivated in hormone-rich, nutrient-rich conditions to grow back into complete plants.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Screening and Verification<\/strong>:\n<ul>\n<li>Transgenic plants are examined using methods such as PCR, Southern blotting, or protein assays to verify the introduced gene&#8217;s existence, expression, and stability.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p><strong>6. Commercialization and Field Testing :\u00a0<\/strong><\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li>The performance of the transgenic plants is evaluated in the field. Prior to commercial cultivation, regulatory approval is sought to guarantee safety.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Agrobacterium-mediated plant transformation<\/h2>\n<p>One popular technique for transferring foreign genes into plants is agrobacterium-mediated gene transfer. This method takes advantage of the soil bacterium <em>Agrobacterium tumefaciens<\/em>&#8216; innate capacity to introduce DNA into plant cells. <strong>Crown gall disease<\/strong> in plants is caused by the bacterium Agrobacterium tumefaciens.<br \/>\nIt causes tumors by transferring a portion of its DNA, known as T-DNA, from the Ti (tumor-inducing) plasmid into the plant genome.<\/p>\n<h3>Ti Plasmid<\/h3>\n<p>The size of the Ti plasmid is considerable, usually between 200 and 800 kilobases.T-DNA (Transfer DNA) Region which is between 10 and 30 kilobases long, gets incorporated into the plant&#8217;s DNA during infection.<\/p>\n<p>The Ti plasmid contains the following genes \/regions<\/p>\n<p><strong>T-DNA<\/strong>\u00a0 : this region contains genes responsible for <strong style=\"font-size: 1em\">Tumor formation:<\/strong><span style=\"font-size: 1em\"> These genes cause unchecked cell division, which results in the creation of a crown gall and tumor and <\/span><strong style=\"font-size: 1em\">Opine synthesis:<\/strong><span style=\"font-size: 1em\"> The bacterium uses the opines produced by the enzymes encoded by these genes as a source of nutrition.<\/span><\/p>\n<p><strong>Border Sequences : <\/strong>The left border (LB) and right border (RB) are two brief (about 25 base pairs) direct repeat sequences that flank the T-DNA. The removal and integration of T-DNA into the plant genome depend on these sequences.<\/p>\n<p><strong>Vir (Virulence) Region :<\/strong> This area, which lies outside the T-DNA, is home to genes that facilitate the transfer process. Proteins that excise the T-DNA are encoded by the Vir genes. These Deliver the T-DNA to the nucleus of the plant cell and aid in its incorporation in the plant&#8217;s genome.<\/p>\n<p><strong>Origin of Replication : <\/strong>permits independent replication of the Ti plasmid in the Agrobacterium.<\/p>\n<p><strong>Opine Catabolism Genes :<\/strong>Opines, which are formed by infected plant cells, can be used by Agrobacterium as a source of carbon and nitrogen<\/p>\n<h4>Steps involved in Agrobacterium mediated gene transfer in plants<\/h4>\n<p>The following crucial steps are involved in the process:<\/p>\n<p><strong>Engineering the Ti Plasmid ( disarmed Ti plasmids ):\u00a0 <\/strong>To stop tumor formation, the T-DNA&#8217;s tumor-inducing genes are eliminated. The desired gene and a selectable marker gene (such as tolerance to antibiotics or herbicides) are added to the T-DNA region.<\/p>\n<p><strong> Preparation of the Vector :<\/strong> A non-tumorigenic, disarmed form of the bacteria is employed.The modified Ti plasmid carrying the desired gene is introduced into Agrobacterium tumefaciens.<\/p>\n<p><strong> Preparing Plant Cells : <\/strong>In order to expose cells for infection, plant tissues or explants (such as leaf discs) are injured. Agrobacterium infection susceptibility is increased by wounding.<\/p>\n<p><strong>Co-Cultivation :<\/strong> The explants are incubated with Agrobacterium tumefaciens.The T-DNA containing the desired gene is then transferred by the\u00a0 bacterium into the plant cell\u2019s genome through the following steps:<\/p>\n<ul>\n<li style=\"list-style-type: none\">\n<ul>\n<li><strong>Attachment<\/strong>: Agrobacterium attaches to the plant cell wall.<\/li>\n<li><strong>T-DNA Transfer:<\/strong> T-DNA is excised from the plasmid and transported into the plant cell nucleus . The bacterium\u2019s Vir (virulence) proteins mediates this transport.<\/li>\n<li><strong>Integration:<\/strong> The T-DNA then integrates randomly into the plant\u2019s chromosomal DNA.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><strong> Selection and Regeneration : <\/strong><span style=\"font-size: 1em\">A selectable marker, such as resistance to antibiotics or herbicides, is used to identify plant cells that have the transgene. <\/span><span style=\"font-size: 1em\">To grow into whole plants, the chosen cells are cultivated in a nutritional medium with plant hormones.<\/span><\/p>\n<p><strong> Confirmation of Transformation : <\/strong>Successful integration and expression of the transgene are verified by molecular methods (such as Southern blot, PCR, or reporter genes like GUS).<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/ae\/Transfection_by_Agrobacterium.svg\/700px-Transfection_by_Agrobacterium.svg.png?20081031132512\" alt=\"File:Transfection by Agrobacterium.svg\" width=\"491\" height=\"421\" class=\"aligncenter\" \/><\/p>\n<pre>A.Agrobacterium cell, B. <span style=\"font-size: 1em\">Agrobacterium DNA, C. T<\/span><span style=\"font-size: 1em\">i Plasmid<\/span><\/pre>\n<div>\n<pre>a.T-DNA ; b.vir genes ; c.replication origin; d.opines catabolism\r\n\r\nD. Plant cell ; E.\u00a0Plant mitochondria ; F.Plant chloroplast ; G.Plant nucleus<\/pre>\n<ol>\n<li>\n<pre>VirA recognition<\/pre>\n<\/li>\n<li>\n<pre>VirA phosphorylates VirG<\/pre>\n<\/li>\n<li>\n<pre>VirG causes transcription of Vir genes<\/pre>\n<\/li>\n<li>\n<pre>Vir genes cut out T-DNA and form nucleoprotein complex (\"T-complex\")<\/pre>\n<\/li>\n<li>\n<pre>T-complex enters plant cytoplasm through T-pilus<\/pre>\n<\/li>\n<li>\n<pre>T-DNA enters into plant nucleus through nuclear pore<\/pre>\n<\/li>\n<li>\n<pre>T-DNA achieves integration<\/pre>\n<\/li>\n<\/ol>\n<p style=\"text-align: center\"><a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Transfection_by_Agrobacterium.svg\" target=\"_blank\" rel=\"noopener\">&#8220;Transfection by Agrobacterium&#8221;<\/a><span>\u00a0by\u00a0<\/span><a>Chandres<\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\" target=\"_blank\" rel=\"noopener\">CC BY-SA 3.0<\/a><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/6f\/Mango_%28Mangifera_indica%29_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_%2832589809932%29.jpg\/800px-Mango_%28Mangifera_indica%29_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_%2832589809932%29.jpg?20211120221215\" alt=\"File:Mango (Mangifera indica) Probably crown gall caused by Agrobacterium tumefaciens (32589809932).jpg\" class=\"aligncenter\" width=\"572\" height=\"429\" \/><\/p>\n<p style=\"text-align: center\"><a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Mango_(Mangifera_indica)_Probably_crown_gall_caused_by_Agrobacterium_tumefaciens_(32589809932).jpg\" target=\"_blank\" rel=\"noopener\">&#8220;Mango (Mangifera indica) Probably crown gall caused by Agrobacterium tumefaciens&#8221;<\/a><span>\u00a0by\u00a0<\/span><a>Scot Nelson Via Wikimedia commons<\/a><a><\/a><a><\/a><span>\u00a0is in the\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/\" target=\"_blank\" rel=\"noopener\">Public Domain, CC0<\/a><\/p>\n<h1>Applications of transgenic plants<\/h1>\n<h2>Agricultural Applications<\/h2>\n<p><strong>Production of Pest and Disease Resistance crops\u00a0<\/strong><\/p>\n<p>For instance, genes from the bacteria Bacillus thuringiensis are present in Bt crops (such as Bt cotton and Bt maize), which reduce the need for pesticides by creating a protein that is harmful to particular pests.<br \/>\nCrop losses are reduced by plants that have been genetically modified to be resistant to bacterial, viral, or fungal diseases.<\/p>\n<p><strong>Resistance to Herbicides<\/strong><br \/>\nCertain pesticides are tolerated by transgenic plants, enabling effective weed management without endangering crops.<br \/>\nFor instance, roundup Glyphosate tolerance in ready soybeans makes controlling weeds easier.<\/p>\n<p><strong>Stress Tolerance<\/strong><\/p>\n<p>Abiotic stressors such as drought, salt, high temperatures, and unfavorable soil conditions are things that plants are designed to survive.<br \/>\nFor instance, rice cultivars that can withstand salt on saline soils.<\/p>\n<p><strong>Increased Production and Development<\/strong><br \/>\nIncreased productivity results from genetic alterations that enhance growth rates, nutrient intake, and photosynthetic efficiency.<\/p>\n<h2>Nutritional Improvements<\/h2>\n<p><strong>Biofortification<\/strong><\/p>\n<p>In order to combat malnutrition, transgenic plants are created to increase the nutritional value of food.<\/p>\n<p>For instance, provitamin A (beta-carotene)-enriched golden rice helps people who are vitamin A deficient.<\/p>\n<p><strong>Improved Quality<\/strong><\/p>\n<p>Features like improved shelf life, taste, or texture are added. For instance, Flavr Savr tomatoes have a longer shelf life since they don&#8217;t rot.<\/p>\n<h2>Applications in Medicine and Pharmacy<\/h2>\n<p><strong>Manufacturing Biopharmaceuticals<\/strong><br \/>\nPlants serve as biofactories that produce medicinal proteins, antibodies, and vaccines. For instance, tobacco plants were modified to yield the ZMapp medication, which is used to treat Ebola.<br \/>\n<strong>\u00a0Edible Vaccines <\/strong><\/p>\n<p>Antigens produced by transgenic plants boost immunity when ingested. Hepatitis B vaccination antigen-expressing potatoes are an example.<\/p>\n<p><strong>\u00a0Reduction of Allergens<\/strong><br \/>\nIt is possible to reduce or completely eradicate allergenic substances in crops such as wheat and peanuts.<\/p>\n<\/div>\n<h2>Industrial Applications<\/h2>\n<p><strong>Biofuel Production<\/strong><br \/>\nTransgenic plants with altered lignin or increased cellulose content increase biomass for the manufacture of biofuel.<br \/>\nFor instance, switchgrass that has been genetically modified to produce ethanol.<\/p>\n<p><strong>Bioplastics<\/strong><br \/>\nBiodegradable plastics are made from modified plants.<br \/>\nTransgenic corn that produces polyhydroxyalkanoates (PHAs) is one example.<\/p>\n<p><strong>Phytoremediation<\/strong><br \/>\nToxins, hydrocarbons, and heavy metals are among the contaminants that are cleaned up by transgenic plants.<br \/>\nFor instance, plants designed to take up mercury or arsenic from polluted soil.<\/p>\n<h2>Environmental\u00a0 Applications<\/h2>\n<p><strong>Decreased Use of Chemicals<\/strong><br \/>\nCrops that are resistant to pests and herbicides reduce the need for chemical pesticides and herbicides, which in turn lessens pollution in the environment.<\/p>\n<p><strong>\u00a0Sequestration of Carbon<\/strong><br \/>\nClimate change can be lessened by producing plants that have improved carbon fixation.<\/p>\n<p>&nbsp;<\/p>\n<h3><strong>Examples of Transgenic Crops and Their Traits<\/strong><\/h3>\n<table style=\"width: 849px;height: 214px\">\n<thead>\n<tr>\n<th style=\"width: 276.625px\"><strong>Crop<\/strong><\/th>\n<th style=\"width: 320.92px\"><strong>Trait<\/strong><\/th>\n<th style=\"width: 209.682px\"><strong>Purpose<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"width: 276.989px\">Bt cotton<\/td>\n<td style=\"width: 321.648px\">Insect resistance<\/td>\n<td style=\"width: 210.045px\">minimizes damage from pests<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 276.989px\">Golden rice<\/td>\n<td style=\"width: 321.648px\">Vitamin A enrichment<\/td>\n<td style=\"width: 210.045px\">Prevents malnutrition<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 276.989px\">Herbicide-tolerant soybean<\/td>\n<td style=\"width: 321.648px;text-align: left\">Herbicide resistance<\/td>\n<td style=\"width: 210.045px\">Makes weed control easier<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 276.989px\">Virus-resistant papaya<\/td>\n<td style=\"width: 321.648px\">Resistance to Papaya Ring Spot Virus<\/td>\n<td style=\"width: 210.045px\">Prevents viral diseases<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 276.989px\">Arctic apple<\/td>\n<td style=\"width: 321.648px\">Non-browning<\/td>\n<td style=\"width: 210.045px\">enhanced appearance and shelf life<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Test Your Understanding<\/h3>\n<p><span><\/p>\n<div id=\"h5p-116\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-116\" class=\"h5p-iframe\" data-content-id=\"116\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Genetic Engineering\"><\/iframe><\/div>\n<\/div>\n<p><\/span><\/p>\n<p><span><\/p>\n<div id=\"h5p-117\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-117\" class=\"h5p-iframe\" data-content-id=\"117\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Genetic Engineering\"><\/iframe><\/div>\n<\/div>\n<p><\/span><\/p>\n","protected":false},"author":1,"menu_order":2,"template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"pb_show_title":"on","pb_short_title":"Transgenic plants ","pb_subtitle":"Transgenic 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