Potato leafroll virus reduces Buchnera aphidocola titer and alters vector transcriptome responses

Area of Science:

• Plant-insect interactions
• Molecular entomology
• Virology

Background:

• Luteoviridae family viruses, like Potato leafroll virus (PLRV), are aphid-transmitted via a circulative, nonpropagative mechanism.
• While PLRV does not replicate in aphids (Myzus persicae), it influences aphid behavior and may involve the aphid obligate symbiont, Buchnera aphidocola.

Purpose of the Study:

• To investigate the transcriptomic changes in green peach aphids (Myzus persicae) infected with PLRV.
• To identify differentially expressed genes (DEGs) and understand their functional roles in PLRV-infected aphids.
• To assess the impact of PLRV infection on the aphid's symbiotic bacteria, Buchnera aphidocola.

Main Methods:

• Illumina sequencing was employed to generate transcriptomes for PLRV-infected and virus-free control Myzus persicae.
• Comparative transcriptome analysis identified 134 differentially expressed genes (DEGs) between the two groups.
• Gene Ontology (GO) database functional classification was used to assign functions to DEGs.

Main Results:

• 64 genes were upregulated and 70 were downregulated in PLRV-carrying aphids.
• Upregulated genes included cytochrome P450s, cuticle production, and development-related genes.
• Downregulated genes involved heat shock proteins and histone modification; PLRV also reduced Buchnera aphidocola titer and altered its metabolic and stress-response transcripts.

Conclusions:

• PLRV infection significantly alters gene expression in Myzus persicae, affecting processes like cuticle synthesis and development.
• PLRV impacts the Buchnera aphidocola symbiont, reducing its abundance and altering transcripts related to stress and metabolism.
• These findings suggest a complex interplay between PLRV, the aphid host, and its symbiont, potentially influencing aphid stress response and transmission dynamics.