miRNA targeting Mpp53 is involved in UV-B irradiation resistance in Myzus persicae

Area of Science:

• Molecular Biology
• Environmental Stress Response
• Insect Physiology

Background:

• Ultraviolet (UV) radiation is a significant environmental stressor impacting organisms.
• Myzus persicae (aphids) are constantly exposed to UV radiation, but their response mechanisms are not fully understood.
• MicroRNAs (miRNAs) are key regulators of gene expression, yet their role in aphid UV-B stress response remains unclear.

Purpose of the Study:

• To investigate the role of miRNAs in aphid responses to UV-B stress.
• To identify specific miRNAs that regulate genes involved in UV-B tolerance in Myzus persicae.
• To elucidate the molecular mechanisms underlying aphid adaptation to UV-B radiation.

Main Methods:

• Quantification of Mpp53 gene expression under varying UV-B exposure durations.
• miRNA prediction and screening targeting Mpp53 in Myzus persicae.
• Luciferase reporter assays to confirm miRNA-target binding and regulatory effects.
• Functional analysis of miRNA overexpression on aphid survival, reproduction, and physical characteristics under UV-B stress.

Main Results:

• Mpp53 expression increased with UV-B exposure duration, and its knockdown reduced aphid survival under UV-B stress.
• Five miRNAs (miR-305-5p, novel_50, novel_80, novel_166, and novel_61) were identified as potential Mpp53 targets.
• Novel_61 directly binds to Mpp53, downregulating its expression and leading to increased aphid mortality, reduced reproduction, and smaller body size under UV-B irradiation.

Conclusions:

• This study is the first to systematically screen and identify miRNAs involved in aphid UV-B stress response.
• Novel_61 plays a crucial role in regulating Mpp53 expression and mediating aphid survival and fitness under UV-B stress.
• The findings deepen the understanding of insect molecular responses to environmental stress and may inform pest control strategies.