Glycoproteins from Russian wheat aphid infested wheat induce defence responses

Area of Science:

• Plant Pathology
• Molecular Plant-Insect Interactions
• Biochemistry

Background:

• Elicitors trigger plant defense mechanisms against pests and pathogens.
• Russian wheat aphid (Diuraphis noxia) infestation in wheat (Triticum aestivum L.) activates specific resistance responses.
• Intercellular wash fluid (IWF) from infested plants contains molecules with elicitor activity.

Purpose of the Study:

• To investigate the elicitor activity in IWF from Russian wheat aphid-infested resistant and susceptible wheat cultivars.
• To isolate and characterize elicitor-active molecules from resistant wheat.
• To assess the role of these molecules in activating plant defense enzymes.

Main Methods:

• Collection and analysis of IWF from resistant (cv Tugela DN) and susceptible (cv Tugela) wheat.
• Assay of peroxidase and beta-1,3-glucanase activities as indicators of elicitor activity.
• Purification of elicitor-active compounds using C-18 reverse phase and concanavalin A Sepharose chromatography.
• Analysis of isolated glycoproteins by SDS-PAGE.

Main Results:

• IWF from infested resistant wheat exhibited high elicitor activity, while IWF from susceptible wheat showed little to no activity.
• Elicitor-active glycoproteins were isolated from resistant wheat IWF.
• These glycoproteins induced higher peroxidase activity in resistant wheat compared to susceptible wheat.
• The isolated glycoproteins separated into three distinct polypeptides.

Conclusions:

• The study identified plant-derived glycoproteins as potent elicitors of defense responses in wheat against Russian wheat aphid.
• These findings suggest that the isolated glycoproteins are general elicitors of plant origin.
• The research provides valuable information for developing novel plant activators to enhance crop defense.