Biological and Molecular Variability Among High Plains virus Isolates

Area of Science:

• Plant Pathology
• Virology
• Molecular Biology

Background:

• High Plains virus (HPV), transmitted by the wheat curl mite (WCM), causes significant maize disease in the U.S. High Plains.
• Understanding HPV variability is crucial for developing effective disease management strategies in maize (Zea mays).

Purpose of the Study:

• To investigate the molecular and biological variability of five High Plains virus isolates.
• To assess the infectivity of these isolates on a resistant maize inbred line.

Main Methods:

• Separation of HPV isolates from co-infecting Wheat streak mosaic virus.
• Time-of-flight mass spectrometry (TOFMS) to analyze amino acid sequence variability of the 32-kDa nucleoprotein (32 np).
• Inoculation of resistant maize (inbred B73) using vascular puncture inoculation (VPI) and viruliferous WCM.

Main Results:

• TOFMS revealed an 18-amino acid sequence at the N-terminus of the 32 np, with observed differences and variability among isolates.
• Three of five HPV isolates successfully infected the resistant maize inbred B73 via VPI.
• Two of these three isolates also infected B73 using WCM, though with low infection rates.

Conclusions:

• Significant molecular variability exists within High Plains virus isolates affecting maize.
• Certain HPV isolates demonstrate the ability to overcome resistance in maize, posing a threat to crop yields.
• Further research is needed to understand the implications of HPV variability for disease control in maize.