Evaluation of Rice Traits Containing H9N2 Subtype Avian Influenza HA Protein Before Commercialization

Area of Science:

• Agricultural biotechnology
• Virology
• Vaccine development

Background:

• H9N2 avian influenza virus (AIV) presents challenges in control due to low pathogenicity and high mutation rates.
• Previous research successfully produced a subunit vaccine using the H9N2 hemagglutinin (HA) protein expressed in rice endosperm, showing efficacy in chickens and mice.

Purpose of the Study:

• To assess the stable expression of the H9N2 HA gene in transgenic rice.
• To evaluate the agronomic traits and gene drift risk of these transgenic rice strains for potential vaccine commercialization.

Main Methods:

• Expression of the H9N2 HA gene in a rice endosperm reactor.
• Intermediate tests on transgenic rice strains (AIV-1 and AIV-3) to confirm gene stability and expression.
• Analysis of agronomic traits (plant height, grain number) and gene drift risk (presence of HA gene in surrounding weeds).

Main Results:

• Stable expression of the H9N2 HA gene was confirmed in transgenic rice strains (AIV-1 and AIV-3).
• Significant optimization of agronomic traits, including plant height and grain number, was observed.
• No evidence of exogenous HA gene transfer to surrounding weed populations, indicating a low risk of gene drift.

Conclusions:

• Transgenic rice expressing the H9N2 HA gene is a viable platform for subunit vaccine production.
• The developed transgenic strains exhibit improved agronomic traits and minimal environmental risk.
• This research provides crucial data supporting the commercialization of plant-based avian influenza subunit vaccines.