28_Recombinant DNA Agriculture

Recombinant DNA in Agriculture

Overview

  • Introduction to recombinant DNA technology in agriculture.

    • Focus on genetic modifications to enhance crop traits.

    • Importance of growth hormones and their potential effects on soil.

Techniques for Introducing Recombinant DNA

  • Techniques reviewed for inserting recombinant DNA into plants.

    • Key examples discussed:

      • Beta-carotene production in rice (Golden Rice).

      • Glyphosate resistance in various crops.

GMO Crops

  • Definition and context of GMO (Genetically Modified Organisms).

    • Specifically refers to transgenic plants created through recombinant DNA technology.

Importance of Genetic Engineering in Modern Agriculture

  • Climate change necessitates the use of genetic engineering.

    • Addressing the rise of superweeds and their impact on crop production.

Key Technique: Agrobacterium tumefaciens

  • Bacterium used for plant infection; critical for genetic engineering.

    • Contains Tumor Inducing (Ti) plasmid that aids in gene transfer to plants.

    • Steps in the process include:

      • Cutting DNA with restriction enzymes.

      • Creating a recombinant Ti plasmid.

      • Introducing this plasmid into plant cells in culture.

      • Resulting in plants exhibiting new traits due to the inserted gene.

Genetic Engineering Applications

  • Luciferase Gene:

    • Example of gene manipulation.

Applications of Recombinant DNA

  • Applications include:

    • Pest resistance.

    • Cleaning up toxic wastes.

    • Producing therapeutic proteins like those that dissolve blood clots.

    • Treating stunted growth with human growth hormone.

Criticisms of GMOs

  • Possible side effects and risks:

    • Unintentional side effects leading to allergies.

    • Potential for GMO crops to contaminate natural fields.

    • Concern about reliance on GMOs reducing biodiversity.

Comparison: Conventional Breeding vs. Transgenesis

  • Conventional breeding often requires multiple backcrossing iterations.

  • Transgenesis allows for direct transfer of beneficial genes, avoiding unwanted genes from relatives.

Golden Rice Development

  • Golden Rice as an example of biotechnology in addressing Vitamin A deficiency.

  • Vitamin A deficiency (VAD) can lead to severe health issues (i.e., blindness in children).

  • Normal rice lacks beta-carotene in its grains; through genetic engineering, the necessary genes have been reactivated.

Steps in Producing Golden Rice

  1. Gene Selection: Identify and isolate genes for beta-carotene synthesis.

  2. Gene Transfer: Use plasmids and Agrobacterium to transfer these genes into rice.

  3. Crossbreeding: Integrate transgenic rice with local variants adaptable to specific climates.

Syngenta Golden Rice Project

  • Developed by Ingo Potrykus and Peter Beyer (1999).

  • FDA and Health Canada approvals in 2018; commercial growth established in the Philippines in 2021.

  • Approval revoked in 2024 by Philippine courts due to public resistance to GMO technology.

Concerns Over GMO Development

  • Societal resistance against GMOs despite potential health benefits.

  • Ethical considerations in the context of human nutrition and dietary needs.

BT Cotton and Insect Resistance

  • Mechanism of action:

    • Crystal proteins activated by insect gut enzymes.

    • Damage to midgut membranes leads to starvation or septicemia in pests.

Ethical Considerations

  • Summary of biotechnology advances in genetically modified foods.

  • Raise critical ethical concerns about environmental impact, human health, and food security.

  • Balancing the costs and benefits of GMOs will shape future agricultural practices.