Wheat gene expression is differentially affected by a virulent Russian wheat aphid biotype

Area of Science:

• Plant-insect interactions
• Molecular plant pathology
• Agricultural entomology

Background:

• Aphid feeding triggers plant defense responses, including signaling pathways and detoxification compounds.
• Russian wheat aphid (Diuraphis noxia) causes significant damage to cereal crops worldwide.
• Wheat-aphid interactions involve compatible (susceptible) and incompatible (resistant) responses.

Purpose of the Study:

• To investigate differential gene expression in wheat during compatible and incompatible interactions with Diuraphis noxia.
• To identify early molecular markers of plant defense against aphid herbivory.
• To understand the spatial and temporal dynamics of defense signaling.

Main Methods:

• Comparative analysis of gene expression levels in wheat tissues after Diuraphis noxia infestation.
• Quantitative assessment of key defense signaling genes (LOX, AOS, AOC) and metabolic pathway genes.
• Time-course analysis of gene expression at 1, 3, 6, and 72 hours post-infestation (hpi).

Main Results:

• Jasmonate (JA)-signaling genes (LOX, AOS, AOC) and cellulose synthase were significantly upregulated earlier and to a higher extent in incompatible interactions (starting at 1 hpi).
• Glycolysis and citric acid cycle genes were downregulated in incompatible interactions, contrasting with compatible interactions.
• JA-signaling gene expression differences between feeding and non-feeding tissues suggest localized defense responses within the first 6 hpi.

Conclusions:

• Early and differential gene upregulation in defense and cell wall reinforcement pathways is a hallmark of incompatible wheat-D. noxia interactions.
• Localized defense signaling at aphid feeding sites is critical in the initial hours of interaction.
• These early molecular events are key components of Russian wheat aphid resistance in wheat.