Plant Metabolic Engineering by Multigene Stacking: Synthesis of Diverse Mogrosides

Area of Science:

• Plant metabolic engineering
• Natural product biosynthesis
• Synthetic biology

Background:

• Mogrosides, health-promoting compounds from monk fruit (Siraitia grosvenorii), are valuable as natural sweeteners and in pharmaceuticals.
• Current production methods face challenges due to inadequate supply and the complexity of chemical synthesis.
• A sustainable and efficient production strategy for mogrosides is needed.

Purpose of the Study:

• To develop a metabolic engineering strategy for mogroside production in plants.
• To establish a gene stacking method for assembling multiple mogroside synthase genes.
• To enable the biosynthesis of mogrosides from 2,3-oxidosqualene in heterologous hosts.

Main Methods:

• An in-fusion based gene stacking strategy (IGS) was employed to assemble six mogroside synthase genes.
• Metabolic engineering was performed on Nicotiana benthamiana and Arabidopsis thaliana.
• High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was utilized for quantitative analysis.

Main Results:

• Engineered Arabidopsis thaliana produced siamenoside I (29.65–1036.96 ng/g FW) and mogroside III (202.75 ng/g FW).
• Engineered Nicotiana benthamiana produced mogroside III (148.30–252.73 ng/g FW) and mogroside II-E (339.27–5663.55 ng/g FW).
• Successful production of specific mogrosides in transgenic plants was confirmed.

Conclusions:

• The developed IGS approach facilitates multigene stacking for complex natural product biosynthesis.
• Metabolic engineering of plants provides a viable platform for mogroside production.
• This study presents a green toolkit for the sustainable production of valuable mogrosides.