Repellency, Toxicity, Gene Expression Profiling and In Silico Studies to Explore Insecticidal Potential of <i>Melaleuca alternifolia</i> Essential Oil against <i>Myzus persicae</i>

• Main Authors: Talha Ali Chohan, Tahir Ali Chohan, Lijun Zhou, Qianqian Yang, Liao Min, Haiqun Cao
• Format: Article
• Language: English
• Published: MDPI AG 2018-10-01
• Series: Toxins
• Subjects: aphid; essential oils; tea tree oil; pest control; docking; MD simulation
• Online Access: https://www.mdpi.com/2072-6651/10/11/425

In the current study, deterrent assay, contact bioassay, lethal concentration (LC) analysis and gene expression analysis were performed to reveal the repellent or insecticidal potential of <i>M. alternifolia</i> oil against <i>M. persicae</i>. <i>M. alternifolia</i> oil demonstrated an excellent deterrence index (0.8) at 2 g/L after 48 h. The oil demonstrated a pronounced contact mortality rate (72%) at a dose of 4 g/L after 24 h. Probit analysis was performed to estimate LC-values of <i>M. alternifolia</i> oil (40%) against <i>M. persicae</i> (LC₃₀ = 0.115 g/L and LC₅₀ = 0.37 g/L respectively) after 24 h. Furthermore, to probe changes in gene expression due to <i>M. alternifolia</i> oil contact in <i>M. persicae</i>, the expression of <i>HSP 60</i>, <i>FPPS I, OSD, TOL and ANT</i> genes were examined at doses of LC₃₀ and LC₅₀. Four out of the five selected genes&#8212;<i>OSD</i>, <i>ANT, HSP 60</i> and <i>FPPS I</i>&#8212;showed upregulation at LC₅₀, whereas, <i>TOL</i> gene showed maximum upregulation expression at LC₃₀. Finally, the major components of <i>M. alternifolia</i> oil (terpinen-4-ol) were docked and MD simulated into the related proteins of the selected genes to explore ligand&#8315;protein modes of interactions and changes in gene expression. The results show that <i>M. alternifolia</i> oil has remarkable insecticidal and deterrent effects and also has the ability to affect the reproduction and development in <i>M. persicae</i> by binding to proteins.