Spatial Distribution and Retention in Loblolly Pine Seedlings of Exogenous dsRNAs Applied through Roots.

Area of Science:

• Plant Science
• Entomology
• Molecular Biology

Background:

• RNA interference (RNAi) using double-stranded RNA (dsRNA) is effective for insect pest control in agriculture.
• Implementation of RNAi in forestry lags due to challenges in dsRNA delivery to target pests.
• The southern pine beetle (SPB) is a significant forest pest susceptible to RNAi, but effective delivery methods are needed.

Purpose of the Study:

• To investigate the translocation and persistence of exogenous dsRNAs within woody plant tissues.
• To determine if dsRNA applied via hydroponics can be absorbed and distributed throughout the loblolly pine plant.
• To assess the potential of plant-mediated dsRNA delivery for forest pest management.

Main Methods:

• Loblolly pine (Pinus taeda) seedlings were exposed to specific dsRNAs through a hydroponic root soak method.
• Plant tissues (root, stem, crown, needle, meristem) were collected at various time points (1, 3, 5, 7 days).
• Exogenous dsRNAs were extracted, detected via gel electrophoresis, and confirmed using Sanger sequencing.

Main Results:

• Exogenously applied dsRNAs were successfully detected in all tested tissue types of loblolly pine.
• dsRNA presence was confirmed across different tissues up to 7 days post-exposure.
• Gel electrophoresis and Sanger sequencing verified the identity and integrity of the recovered dsRNAs.

Conclusions:

• Root drench application of dsRNA is a feasible method for delivering RNAi agents into host plants.
• This approach shows potential for systemic delivery of RNAi to combat tree-feeding pests like the southern pine beetle.
• Further research can optimize plant-mediated dsRNA delivery for effective forest pest suppression using RNAi technology.