Enhanced exogenous RNAi by loop-ended double-stranded RNA in plants.

Area of Science:

• Molecular Biology
• Plant Science
• Biotechnology

Background:

• Exogenous RNA interference (exoRNAi) offers potential for gene silencing but lacks robust efficiency.
• Developing effective exoRNAi technologies is crucial for various biological applications.

Purpose of the Study:

• To evaluate a novel Loop-ended dsRNA (ledRNA) design for enhancing exoRNAi efficacy.
• To assess the stability, delivery, and gene silencing capabilities of ledRNA in plants, fungi, and insects.

Main Methods:

• Designed ledRNA with a dumbbell-like structure featuring a nick site.
• Applied ledRNA topically to various plant tissues (leaves, cotyledons, meristems, roots).
• Introduced ledRNA into fungal cultures (Fusarium oxysporum) and administered orally to insects (green peach aphids).

Main Results:

• ledRNA showed higher accumulation and broader distribution in plant tissues compared to traditional hairpin RNA (hpRNA).
• Topical ledRNA application effectively silenced the FAD2 gene in N. benthamiana, increasing monounsaturated fatty acids.
• ledRNA successfully downregulated target genes in Fusarium oxysporum and reduced fecundity in Myzus persicae.

Conclusions:

• ledRNA demonstrates superior stability, uptake, and movement in plants, enhancing exoRNAi efficacy.
• ledRNA is effective across diverse kingdoms, highlighting its potential as a versatile tool for gene expression manipulation.