Rerouting plant terpene biosynthesis enables momilactone pathway elucidation

Area of Science:

• Plant biochemistry
• Metabolic engineering
• Chemical ecology

Background:

• Momilactones, found in rice, exhibit allelopathic activity, inhibiting competing plant growth.
• Engineering crops for momilactone production could offer a sustainable weed management strategy.
• The complete momilactone biosynthetic pathway has not been fully elucidated, hindering production efforts.

Purpose of the Study:

• To elucidate and reconstitute the complete momilactone biosynthetic pathway in a heterologous host.
• To overcome yield limitations in multistep diterpene production.
• To validate the allelopathic activity of engineered momilactones.

Main Methods:

• Rapid gene screening in Nicotiana benthamiana.
• Rerouting diterpene biosynthesis from the chloroplast to the cytosolic mevalonate pathway.
• Isolation and bioassays of pure momilactone B.

Main Results:

• Successfully discovered and reconstituted a complete momilactone biosynthetic pathway.
• Achieved over 10-fold yield improvement in momilactone production compared to native rice systems.
• Demonstrated significant inhibition of Arabidopsis thaliana germination and root growth by momilactone B.
• Showcased broad applicability by improving forskolin and taxadiene production.

Conclusions:

• Rerouting diterpene biosynthesis to the cytosolic mevalonate pathway is an effective strategy to enhance intermediate and product yields.
• This approach enables the efficient production of allelopathic compounds like momilactones.
• The methodology is broadly applicable for the heterologous production of valuable plant natural products.