The carotenoid biosynthetic pathway: thinking in all dimensions

Area of Science:

• Plant biochemistry and molecular biology
• Metabolic engineering and synthetic biology

Background:

• The carotenoid biosynthetic pathway is crucial for plant photosynthesis, photoprotection, development, and producing compounds for human nutrition, flavor, and fragrance.
• Carotenoids are vital plant compounds, influencing photosynthesis, development, and human health, making their biosynthetic pathway a key target for metabolic engineering, exemplified by Golden Rice.

Purpose of the Study:

• To evaluate the possibility of predictive metabolic engineering of the carotenoid biosynthetic pathway.
• To highlight the knowledge gaps concerning the spatial organization and dynamics of the carotenoid pathway within plant cells.

Main Methods:

• Review and synthesis of current knowledge on the carotenoid biosynthetic pathway.
• Discussion of the limitations in understanding pathway assembly, enzyme localization, and substrate/product trafficking.
• Argument for investigating the three-dimensional state and dynamic nature of pathways within plastids.

Main Results:

• The current understanding of the carotenoid pathway is largely a 'parts list' with insufficient knowledge of enzyme localization, assembly, and trafficking.
• Predictive metabolic engineering is hindered by the lack of understanding of the pathway's spatial and dynamic organization.

Conclusions:

• Predictive metabolic engineering of carotenoid pathways necessitates a deeper understanding of their three-dimensional structure and dynamics within plastids.
• Development of advanced visualization tools is crucial for accurately representing the dynamic nature of biosynthetic pathways and enabling successful metabolic engineering.