Agrobacterium-mediated transformation

Definition

Agrobacterium-mediated transformation is a method of introducing foreign DNA into plant cells using the bacterium Agrobacterium tumefaciens, which naturally transfers part of its DNA (T-DNA) into the host plant's genome. This process takes advantage of the bacterium's ability to infect plants, allowing scientists to create transgenic plants that express new traits, such as disease resistance or improved nutritional content. This method has revolutionized plant biotechnology and is widely used in agricultural applications.

5 Must Know Facts For Your Next Test

1. Agrobacterium tumefaciens is a soil bacterium known for causing crown gall disease in plants by transferring T-DNA into the host's genome.
2. The process can be enhanced by using binary vectors, which facilitate the delivery of genes into Agrobacterium for subsequent transfer to plants.
3. This technique is preferred for dicotyledonous plants, as it provides higher transformation efficiency compared to monocots.
4. Agrobacterium-mediated transformation has led to the development of crops with improved resistance to pests, diseases, and environmental stressors.
5. Regeneration of whole plants from transformed cells is a critical step in this method, requiring tissue culture techniques.

Review Questions

• How does Agrobacterium tumefaciens naturally facilitate the genetic transformation of plants, and what role does T-DNA play in this process?
  • Agrobacterium tumefaciens infects plants by transferring a portion of its DNA, known as T-DNA, into the host plant's genome. This T-DNA contains genes that can confer various traits, and when scientists harness this natural process, they can introduce additional genes of interest into the plant. The successful integration of T-DNA into the plant’s genome allows the transformed plant cells to express new characteristics, making Agrobacterium a powerful tool in plant biotechnology.
• Discuss the advantages of using Agrobacterium-mediated transformation compared to other methods like biolistics in creating transgenic plants.
  • Agrobacterium-mediated transformation offers several advantages over biolistics, including higher transformation efficiency and lower damage to plant tissues. While biolistics can cause physical damage due to the high-velocity delivery of DNA, Agrobacterium’s natural infection mechanism leads to more stable integration of T-DNA without harming surrounding cells. Additionally, this method allows for precise insertion of genetic material and has been successfully used for a wide range of plant species, especially dicots.
• Evaluate the impact of agrobacterium-mediated transformation on agricultural practices and food security in modern society.
  • Agrobacterium-mediated transformation has significantly impacted agricultural practices by enabling the development of transgenic crops with enhanced traits such as pest resistance, herbicide tolerance, and improved nutritional profiles. These innovations help reduce reliance on chemical pesticides and fertilizers, leading to more sustainable farming practices. As global populations continue to grow and climate change poses new challenges to food production, these genetically modified crops can contribute to food security by increasing yield stability and providing essential nutrients, ultimately playing a crucial role in addressing hunger and malnutrition worldwide.

Related terms

Transgenic plants: Plants that have been genetically modified to contain genes from other organisms, often resulting in desirable traits.

T-DNA: Transfer DNA that is integrated into the plant's genome during Agrobacterium-mediated transformation, carrying genes of interest.

Biolistics: A different technique for transforming plant cells using high-velocity microprojectiles to deliver DNA, often used when Agrobacterium is not effective.