Leveraging Walnut Somatic Embryos as a Biomanufacturing Platform for Recombinant Proteins and Metabolites

Area of Science:

• Biotechnology
• Plant biotechnology
• Molecular farming

Background:

• Biomanufacturing is crucial for producing compounds like vaccines and diagnostics.
• The COVID-19 pandemic emphasized the need for diverse biomanufacturing platforms.
• Plant-based systems offer potential for scalable and cost-effective production.

Purpose of the Study:

• To explore the potential of walnut somatic embryos as a biomanufacturing platform.
• To express SARS-CoV-2 spike proteins (receptor binding domain and ectodomain) in walnut embryos.
• To assess the production of betanin, a valuable plant pigment, in the same system.

Main Methods:

• Walnut somatic embryogenic system established and transformed.
• Stable expression of recombinant SARS-CoV-2 spike proteins achieved.
• In vitro propagation and selection of transformed embryo lines.
• Quantification of recombinant proteins and betanin pigment.

Main Results:

• Recombinant SARS-CoV-2 spike proteins detected at 3-14 µg/g dry weight.
• Betanin pigment produced at high yields (650 mg/g), exceeding red beet.
• Walnut somatic embryos demonstrated stable transformation and propagation.
• Initial yields of recombinant proteins are lower than conventional platforms but show potential.

Conclusions:

• Walnut somatic embryos represent a promising, novel biomanufacturing platform.
• The system can be optimized for producing both specialized proteins and high-value metabolites.
• This approach diversifies biomanufacturing options for research and industrial applications.