Pest-Resistant Plants: RNA Interference (RNAi)
Mechanism of RNA interference (RNAi) and its use in developing nematode-resistant tobacco plants as a biological pest control strategy.
What is Pest-Resistant Plants: RNA Interference (RNAi)?
A biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules.
Key points
- Describe the mechanism of RNA interference (RNAi).
- Identify the key components involved in the RNAi pathway (dsRNA, Dicer, siRNA, RISC, target mRNA).
- Explain how RNAi is utilized to develop pest-resistant plants.
- Provide an example of an RNAi-based pest-resistant plant (e.g., nematode-resistant tobacco).
Common exam trap
Confusing RNAi with gene editing technologies like CRISPR, which target DNA.
Definitions
- Term
RNA Interference (RNAi)
- Meaning
A biological process in which RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules.
- Term
Double-stranded RNA (dsRNA)
- Meaning
RNA composed of two complementary strands, which acts as the trigger for the RNAi pathway.
- Term
Dicer
- Meaning
An enzyme that cleaves dsRNA and pre-microRNA into small interfering RNA (siRNA) and microRNA (miRNA) molecules, respectively.
- Term
Small Interfering RNA (siRNA)
- Meaning
Short, double-stranded RNA molecules, typically 20-25 nucleotides in length, that function in RNAi by guiding the RISC to target mRNA.
- Term
RNA-induced Silencing Complex (RISC)
- Meaning
A multiprotein complex that incorporates one strand of a small interfering RNA (siRNA) or microRNA (miRNA), and cleaves complementary mRNA.
- Term
Gene Silencing
- Meaning
The regulation of gene expression in a cell to prevent the expression of a certain gene. In RNAi, it occurs at the post-transcriptional level.
- Term
*Meloidogyne incognita*
- Meaning
A species of root-knot nematode, a major agricultural pest that infects the roots of many plants, causing galls and reducing crop yield.
Learning objectives
Describe the mechanism of RNA interference (RNAi).
Identify the key components involved in the RNAi pathway (dsRNA, Dicer, siRNA, RISC, target mRNA).
Explain how RNAi is utilized to develop pest-resistant plants.
Provide an example of an RNAi-based pest-resistant plant (e.g., nematode-resistant tobacco).
Discuss the advantages of using RNAi for pest control in agriculture.
Prerequisites
Basic understanding of DNA, RNA, and proteins.
Knowledge of the Central Dogma of Molecular Biology (transcription and translation).
Concepts of gene expression and gene regulation.
Basic understanding of genetic engineering and transgenic organisms.
Common mistakes
Confusing RNAi with gene editing technologies like CRISPR, which target DNA.
Believing RNAi directly targets DNA instead of mRNA.
Not understanding the role of dsRNA as the trigger for the RNAi pathway.
Assuming RNAi is a universal cure for all plant diseases, rather than a specific gene-silencing mechanism.
Forgetting the key enzymes/complexes involved (Dicer, RISC).
Keywords
RNAi
RNA interference
gene silencing
dsRNA
Dicer
siRNA
RISC
nematode resistance
transgenic plants
biotechnology
*Meloidogyne incognita*
post-transcriptional regulation
Practice preview
Which of the following is the primary mechanism by which RNA interference (RNAi) leads to pest resistance in plants?…
easy
What is the primary mechanism by which RNA interference (RNAi) confers pest resistance in plants?…
easy
In the development of nematode-resistant tobacco plants using RNAi, what was the source of the double-stranded RNA (dsRNA) that triggered the RNAi pathway?…
medium