Plin-amiR, a pre-microRNA-based technology for controlling herbivorous insect pests

Area of Science:

• Agricultural Science
• Molecular Biology
• Entomology

Background:

• Cotton bollworm (Helicoverpa armigera) causes significant crop losses.
• Existing pest control methods like Bacillus thuringiensis (Bt) toxins face evolved insect resistance.
• New strategies are crucial for managing resistant pest populations.

Purpose of the Study:

• To develop a novel plant-based RNA interference strategy against Helicoverpa armigera.
• To investigate the efficacy of plant-expressed insect pre-microRNAs (pre-amiRs) for pest control.

Main Methods:

• Engineered insect pre-microRNA (pre-miR) transcripts containing artificial microRNAs (amiRs) targeting essential insect genes.
• Expression of these modified pre-amiRs in transgenic Nicotiana benthamiana plants.
• Assessment of plant-expressed insect pre-amiRs (plin-amiRs) for their processing and insecticidal activity against H. armigera.

Main Results:

• Modified pre-miRs were largely unprocessed within the transgenic plants.
• H. armigera feeding on plin-amiR-expressing plants exhibited increased mortality.
• Insects showed developmental abnormalities and delayed growth rates when exposed to the engineered plants.

Conclusions:

• Plant-expressed insect pre-amiRs (plin-amiRs) represent a viable new strategy for protecting crops against herbivorous insects.
• This approach offers an alternative to existing pest control methods facing resistance.
• TK-RNAi using modified pre-miRs shows promise for sustainable agricultural pest management.